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Sample records for reservoir dam nj

  1. Investigating leaks in dams and reservoirs

    International Nuclear Information System (INIS)

    2003-01-01

    Millions of people throughout the world depend on dams and reservoirs for electricity, water and flood protection. Dams require significant investment to build and maintain, and yet their usefulness and integrity are constantly threatened by leakage and sedimentation. Isotope hydrology techniques, combined with conventional analytical methods, are a cost-effective tool to reduce such threats. The International Atomic Energy Agency is promoting their use to protect these investments and improve management, particularly by supporting specialized teams of scientists and engineers to investigate dam leakage in African countries on request. (IAEA)

  2. The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

    International Nuclear Information System (INIS)

    Amini, Ali Reza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

    2008-01-01

    To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams

  3. Seismic response of concrete gravity dams with finite reservoir

    International Nuclear Information System (INIS)

    Baumber, T.; Ghobarah, A.

    1992-01-01

    In most previous analyses of dam responses to earthquake ground motion, the upstream reservoir is assumed to be infinite in length and completely straight. The meandering nature of the river system, however, results in the creation of a finite length reservoir upstream of the dam structure. A study was carried out to examine the effects of the finite length of the reservoir on the dynamic behavior of the monolith. The effect of excitation of the far end of the boundary on the monolith's response is also of interest. The dam-foundation-reservoir system is modelled using a sub-structuring approach. The analysis is conducted in the frequency domain and utilizes the finite element technique. The water in the reservoir is assumed to be compressible, inviscid, and irrotational. The upstream reservoir is assumed to have a rectangular cross-section. It was found that the finite length reservoir assumption results in supplementary response peaks in the monolith's response. The finite reservoir length allows the reservoir to resonate both in horizontal and vertical directions. The magnitude and spacing of these supplementary response peaks are dependent on the length of the reservoir. The phase of the ground motion which affects the far end boundary of the reservoir was also found to have a significant effect on the dam monolith's response. 8 refs., 5 figs

  4. 33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the Interior, through his agent, the Lower Colorado River Authority (LCRA) shall operate the Marshall Ford Dam...

  5. Can Dams and Reservoirs Cause Earthquakes?

    Indian Academy of Sciences (India)

    induced earthquakes in that region. Figure 1. A cartoon to illus- trate the spatial relation- ships between dam, reser- ... learning experience for us graduate students. Thus, on that ... infallibility and persuasiveness as in Euclidean geometry. The.

  6. DAM-LAKEFRONT PLAZA: Revitalization of an Agriculture Reservoir Dam in Kashar-Tirana/Albania

    Directory of Open Access Journals (Sweden)

    Valbona Koçi

    2014-12-01

    Full Text Available The Dam-Lakefront Plaza in Kashar-Tirana/Albania is a research project that proposes not only the re-consideration and reinforcement of the artificial Reservoirs Dams built during Socialism in Albania, but envisions the maintenance of dams and revitalization of the lakeside area promoting the public-private collaboration. In addition, it envisions the generation of qualitative and lively public spaces in sub-urban areas as well. Admitting the artificial lakes as specific nodes of man-made infrastructure in the landscape, and consequently the dams (together with the drainage channels as important hydrotechnic elements of the flood protection infrastructure, this research intends to elaborate on one type of landscape infrastructure - the vertical screens, offering a mediation between the natural and built landscape.

  7. Mapping seepage through the River Reservoir Dam near Eagar, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Rollins, P.

    2005-06-30

    This article describes the actions taken to address an unusual amount of water seepage from the left abutment weir-box of the River Reservoir dam built in 1896 near Eagar, Arizona. Upon noting the seepage in March 2004, the operator, Round Valley Water Users Association, contacted the State of Arizona who funded the investigation and subsequent remediation activities through an emergency fund. The dam was originally built with local materials and did not include a clay core. It was modified at least four times. The embankment sits on basalt bedrock and consists of clayey soils within a rock-fill shell. AquaTrack technology developed by Willowstick Technologies was used to assess the deteriorating situation. AquaTrack uses a low voltage, low amperage audio-frequency electrical current to energize the groundwater or seepage. This made it possible to follow the path of groundwater between the electrodes. A magnetic field was created which made it possible to locate and map the field measurements. The measured magnetic field data was processed, contoured and correlated to other hydrogeologic information. This identified the extent and preferential flow paths of the seepage. The survey pinpointed the area with the greatest leakage in both the horizontal and vertical directions. Fluorescent dyes were also used for tracer work to confirm previous findings that showed a serious seepage problem. The water of the reservoir was lowered to perform remedial measures to eliminate the risk of immediate failure. Funding for a more permanent repair is pending. 10 figs.

  8. Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2011 - February 2012

    Science.gov (United States)

    Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.; Hatton, Tyson W.

    2013-01-01

    The movements and dam passage of juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. The purpose of the study was to provide information to aid with decisions about potential alternatives for improving downstream passage conditions for juvenile salmonids in this flood-control reservoir. In 2011, a total of 411 hatchery fish and 26 wild fish were tagged and released during a 3-month period in the spring, and another 356 hatchery fish and 117 wild fish were released during a 3-month period in the fall. A series of 16 autonomous hydrophones throughout the reservoir and 12 hydrophones in a collective system near the dam outlet were used to determine general movements and dam passage of the fish over the life of the acoustic transmitter, which was expected to be about 3 months. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back to the head of the reservoir. Most fish were detected near the temperature control tower at least once. The median time from release near the head of the reservoir to detection within about 100 meters of the dam outlet at the temperature control tower was between 5.7 and 10.8 days, depending on season and fish origin. Dam passage events occurred over a wider range of dates in the spring and summer than in the fall and winter, but dam passage numbers were greatest during the fall and winter. A total of 10.5 percent (43 of 411) of the hatchery fish and 15.4 percent (4 of 26) of the wild fish released in the spring are assumed to have passed the dam, whereas a total of 25.3 percent (90 of 356) of the hatchery fish and 16.9 percent (30 of 117) of the wild fish released in the fall are assumed to have passed the dam. A small number of fish passed the dam after their transmitters had stopped working and were detected at

  9. Investigation of seasonal thermal flow in a real dam reservoir using 3-D numerical modeling

    Directory of Open Access Journals (Sweden)

    Üneş Fatih

    2015-03-01

    Full Text Available Investigations indicate that correct estimation of seasonal thermal stratification in a dam reservoir is very important for the dam reservoir water quality modeling and water management problems. The main aim of this study is to develop a hydrodynamics model of an actual dam reservoir in three dimensions for simulating a real dam reservoir flows for different seasons. The model is developed using nonlinear and unsteady continuity, momentum, energy and k-ε turbulence model equations. In order to include the Coriolis force effect on the flow in a dam reservoir, Coriolis force parameter is also added the model equations. Those equations are constructed using actual dimensions, shape, boundary and initial conditions of the dam and reservoir. Temperature profiles and flow visualizations are used to evaluate flow conditions in the reservoir. Reservoir flow’s process and parameters are determined all over the reservoir. The mathematical model developed is capable of simulating the flow and thermal characteristics of the reservoir system for seasonal heat exchanges. Model simulations results obtained are compared with field measurements obtained from gauging stations for flows in different seasons. The results show a good agreement with the field measurements.

  10. Information collection and processing of dam distortion in digital reservoir system

    Science.gov (United States)

    Liang, Yong; Zhang, Chengming; Li, Yanling; Wu, Qiulan; Ge, Pingju

    2007-06-01

    The "digital reservoir" is usually understood as describing the whole reservoir with digital information technology to make it serve the human existence and development furthest. Strictly speaking, the "digital reservoir" is referred to describing vast information of the reservoir in different dimension and space-time by RS, GPS, GIS, telemetry, remote-control and virtual reality technology based on computer, multi-media, large-scale memory and wide-band networks technology for the human existence, development and daily work, life and entertainment. The core of "digital reservoir" is to realize the intelligence and visibility of vast information of the reservoir through computers and networks. The dam is main building of reservoir, whose safety concerns reservoir and people's safety. Safety monitoring is important way guaranteeing the dam's safety, which controls the dam's running through collecting the dam's information concerned and developing trend. Safety monitoring of the dam is the process from collection and processing of initial safety information to forming safety concept in the brain. The paper mainly researches information collection and processing of the dam by digital means.

  11. Large Dam Effects on Flow Regime and Hydraulic Parameters of river (Case study: Karkheh River, Downstream of Reservoir Dam

    Directory of Open Access Journals (Sweden)

    Farhang Azarang

    2017-06-01

    Full Text Available Introduction: The critical role of the rivers in supplying water for various needs of life has led to engineering identification of the hydraulic regime and flow condition of the rivers. Hydraulic structures such dams have inevitable effects on their downstream that should be well investigated. The reservoir dams are the most important hydraulic structures which are the cause of great changes in river flow conditions. Materials and Methods: In this research, an accurate assessment was performed to study the flow regime of Karkheh river at downstream of Karkheh Reservoir Dam as the largest dam in Middle East. Karkheh River is the third waterful river of Iran after Karun and Dez and the third longest river after the Karun and Sefidrud. The Karkheh Dam is a large reservoir dam built in Iran on the Karkheh River in 2000. The Karkheh Reservoir Dam is on the Karkheh River in the Northwestern Khouzestan Province, the closest city being Andimeshk to the east. The part of Karkheh River, which was studied in this research is located at downstream of Karkheh Reservoir Dam. This interval is approximately 94 km, which is located between PayePol and Abdolkhan hydrometric stations. In this research, 138 cross sections were used along Karkheh River. Distance of cross sections from each other was 680m in average. The efficient model of HEC-RAS has been utilized to simulate the Karkheh flow conditions before and after the reservoir dam construction using of hydrometric stations data included annually and monthly mean discharges, instantaneous maximum discharges, water surface profiles and etc. Three defined discharges had been chosen to simulate the Karkheh River flow; maximum defined discharge, mean defined discharge and minimum defined discharge. For each of these discharges values, HEC-RAS model was implemented as a steady flow of the Karkheh River at river reach of study. Water surface profiles of flow, hydraulic parameters and other results of flow regime in

  12. Dam-Break Flood Analysis Upper Hurricane Reservoir, Hartford, Vermont

    National Research Council Canada - National Science Library

    Acone, Scott

    1995-01-01

    .... Various dam break flood conditions were modeled and inundation maps developed. Based on this analysis the dam is rated a Class 2 or significant hazard category in terms of its potential to cause downstream damage...

  13. Design and Construction of Dams, Reservoirs, and Balancing Lakes

    International Nuclear Information System (INIS)

    Lemperiere, F.

    2003-01-01

    The general data presented in sections two and three gives an idea of the extreme diversity of the millions of very large or very small dams worldwide. Dam design and construction methods for the most usual types of large dams are presented and justified in section four. The possibility and usefulness of building as many dams in the 21. century as have been built in the 20. is analyzed in section six. (author)

  14. Three-dimensional migration behavior of juvenile salmonids in reservoirs and near dams

    OpenAIRE

    Li, Xinya; Deng, Zhiqun D.; Fu, Tao; Brown, Richard S.; Martinez, Jayson J.; McMichael, Geoffrey A.; Trumbo, Bradly A.; Ahmann, Martin L.; Renholds, Jon F.; Skalski, John R.; Townsend, Richard L.

    2018-01-01

    To acquire 3-D tracking data on juvenile salmonids, Juvenile Salmon Acoustic Telemetry System (JSATS) cabled hydrophone arrays were deployed in the forebays of two dams on the Snake River and at a mid-reach reservoir between the dams. The depth distributions of fish were estimated by statistical analyses performed on large 3-D tracking data sets from ~33,500 individual acoustic tagged yearling and subyearling Chinook salmon and juvenile steelhead at the two dams in 2012 and subyearling Chinoo...

  15. Use of isotopes techniques during the life cycle of dams and reservoirs: cases in Latin American

    International Nuclear Information System (INIS)

    Leon, S.H.

    2006-01-01

    In fact, the combined use of isotope and conventional techniques is considered a reliable tool for studying problems related to dam safety and has become a new culture for civil / dam engineers, hydro geologists and researchers who involve in water resource management fields. The use of natural (environmental) and artificial isotopes as tracers together with systematic analyses of the hydrochemistry, electrical conductivity and temperature profiles data during the investigation and monitoring of leakage and seepage in dams and reservoirs are now becoming popular among the dam owners in seeking the best solution for dam related problems. Many studies and experiences worldwide on effective dam management programmes have indicated that any investigation about leakages and seepages are not possible to be accomplished successfully without synergic application of the conventional technologies and isotopic techniques. The major advancement in this area is the measurements study for establishment of baseline hydrogeology at each hydraulic work project like dams and reservoirs. The parameters include hydro chemicals, isotopic and geologic in each basin, river, reservoir, dams, tunnels and groundwater which provide high value information for decision making during all the stages in the life cycle of the dams. Many hydroelectric and water supply projects in latin america apply these investigation strategies. The main target is to investigate and understand the water movement around the dam and its vicinity. Then the specialised work teams will decide for the effective and economic monitoring activities and the implementation of the recommended remedial measures to ensure high standards of safety and security of the large dams and reservoirs. A typical example of specific leakage investigation of la Honda dam is briefly discussed. (Author)

  16. Effect of reservoir characteristics on the response of concrete gravity dams

    International Nuclear Information System (INIS)

    Baumber, T.; Ghobarah, A.

    1992-01-01

    In most previous analyses of dam responses to earthquake ground motion, the upstream reservoir is assumed to be infinite in length with horizontal bottom. This is rarely the actual geometry of a reservoir, as the upstream valley typically has complex geometry. A study was carried out to examine the effects of the geometry of the reservoir on the dynamic behavior of the monolith. The dam-foundation-reservoir system is modelled using a sub-structuring approach. The reservoir is modelled using a finite element formulation. The absorptive capacity of the reservoir's foundation is idealized as a one-dimensional boundary condition at the reservoir-foundation interface. The reservoir bottom is assumed to be sloping. It was found that the assumed shape of the upstream reservoir significantly affects the overall response of the dam-foundation-reservoir system. The frequencies and magnitudes of the response peaks are affected by the geometry of the reservoir. It was also found that the value of the wave reflection coefficient at the reservoir bottom has a significant effect on the system's response. 6 refs., 5 figs

  17. Environmental-impact assessment of dams and reservoir projects (review and a case study)

    International Nuclear Information System (INIS)

    Shah, S.M.

    2009-01-01

    Dams and reservoirs are among one of the most sensitive of all development Project, in terms of pervasiveness of their influence in altering the environmental conditions and resources. In the present study, major dams and reservoir projects are reviewed, from the environmental point of view. Dams and Reservoir projects bring about major changes in the immediate environment, thus affecting public health, settlements, farmlands, roads and historical sites. Impacts on human population and wildlife may be profound. Tropical diseases, involving fresh-water hosts or vectors in their transmission, are often common around new reservoirs. Large lakes create limnological changes, excessive evaporation, seepage, disturbance in water-table and increased tendencies of landslides and earthquakes. Micro climatic changes are possible, such as fog formation, increased cloudiness and modified rainfall-patterns. Retention of sediment results in silting up of reservoirs. Water shortages on mountain rivers may leave unsightly dry river-beds below a dam. Sediment deposition and growth of vegetation in reservoir affects the water-extraction for navigation power-generation and fishing. Various dams and reservoir projects in the world are critically studied, in terms of creating environmental impacts. The Kala Bagh Dam project (Pakistan), which is ready for construction, has been analysed as a case study, by matrix method. Analyses show that adverse effects of this dam are less than the benefits. It is recommended that based on the experience, appropriate lines and strategies may be drawn up to evaluate the local projects. Multidisciplinary experts need to be involved, for assessing environmental impacts and suggesting mitigation measures, to combat the adverse effects. (author)

  18. National Dam Safety Program. Clove Lake Dam (NJ 00259) Delaware River Basin, Shimers Brook, Sussex County, New Jersey. Phase I Inspection Report.

    Science.gov (United States)

    1981-08-01

    it be reclassified as low hazard. The spillway will pass the 100-year flood and is considered adequate. e. Ownership. The dam is owned by Clubhouse ...Associates. For information, contact Mr. Gerald Roby, Clubhouse Associates, RD 4, Box 108, Montague, New Jersey 07827. f. Purpose. The Clove Lake Dam...into what appears to be a man-made lake downstream of Clove Lake Dam about 0.5 mile. Although no homes are presently constructed around this downstream

  19. Dam break flood wave under different reservoir's capacities and ...

    Indian Academy of Sciences (India)

    Farhad Hooshyaripor

    2017-07-14

    Jul 14, 2017 ... Dam failure has been the subject of many hydraulic engineering studies due to its ... the role of the side slopes on dam break flood wave, such that lower side slope ... improve the inputs and advance our knowledge about the.

  20. The quality of surface waters of the dam reservoir Mexa, Northeast of Algeria

    Directory of Open Access Journals (Sweden)

    Bahroun Sofia

    2017-09-01

    Full Text Available In this work, we have conducted a physicochemical study that assesses the impact of agricultural activities and urban domestic wastewater on the surface water quality of the dam reservoir Mexa in the area of El-Taref, which is located in the eastern coastal basin of Constantine. 36 samplings have been conducted for three years (2010, 2011 and 2012, at the rate of one sampling per month on the dam reservoir water; 36 samples have been analysed. The samples taken have been subjected to an in situ measurement of physicochemical parameters (temperature, hydrogen potential, electric conductivity and dissolved oxygen and laboratory analysis (anions, cations, biological oxygen demand, chemical oxygen demand, organic matter, phosphate, nitrate, nitrite and ammonium. Concentrations of various organic and inorganic pollutants varied from one month to another and from one year to another. From a temporal point of view, the contamination of water of the dam reservoir Mexa varies according to climatic conditions, being generally low during the winter period and high during the low-flow periods. The results obtained reveal that water of the dam reservoir Mexa is fairly contaminated. It is certain that the dam reservoir is subject to pollution of agricultural and urban origin.

  1. Dharmic projects, imperial reservoirs, and new temples of India: An historical perspective on dams in India

    Directory of Open Access Journals (Sweden)

    Morrison Kathleen

    2010-01-01

    Full Text Available As international attention continues to focus on large dam projects across Asia, it is worth noting that conflicts over the politics of and environmental changes caused by dams in India are not new. Population dislocation, siltation, disease, floods caused by catastrophic dam failure, raised water tables, high costs and low returns-all of these concerns, and others, can be discussed in the context of reservoir projects ten, one hundred, or even one thousand years old. In this paper, I identify some of the major issues in the political ecology of contemporary dam projects and show how these same issues have played out in southern India over the last thousand years, suggesting that historical attention to the cultural and political context of reservoir construction might help us to understand some aspects of contemporary conflicts.

  2. Assessing the Habitat Suitability of Dam Reservoirs: A Quantitative Model and Case Study of the Hantan River Dam, South Korea

    Directory of Open Access Journals (Sweden)

    Hyeongsik Kang

    2016-11-01

    Full Text Available The main objective of this study was to investigate ecologically healthy regions near a dam reservoir. This study developed a model for assessing habitat suitability as a proxy for the ecological value of reservoirs. Three main factors comprising nine assessment variables were selected and classified as having a habitat suitability (HS between 0 and 1: (1 geomorphic factors of altitude, slope steepness, and slope aspect; (2 vegetation factors of forest physiognomy, vegetation type, and tree age; and (3 ecological factors of land cover, ecological quality index, and environmental conservation value assessment. The spatial distribution of the nine HS indices was determined using geographic information systems and combined into one HS index value to determine ecologically healthy regions. The assessment model was applied to areas surrounding the Hantan River Dam, South Korea. To verify the model, wildlife location data from the national ecosystem survey of the Ministry of Environment were used. Areas with an HS index between 0.73 and 1 were found to contain 72% of observed wildlife locations. Ecologically healthy areas were identified by adding the indices of each variable. The methods shown here will be useful for establishing ecological restoration plans for dam reservoirs in South Korea.

  3. Modeling of Reservoir Inflow for Hydropower Dams Using Artificial ...

    African Journals Online (AJOL)

    The stream flow at the three hydropower reservoirs in Nigeria were modeled using hydro-meteorological parameters and Artificial Neural Network (ANN). The model revealed positive relationship between the observed and the modeled reservoir inflow with values of correlation coefficient of 0.57, 0.84 and 0.92 for Kainji, ...

  4. The impact of foundation conditions on the design and construction of the Snake Lake Reservoir dams

    International Nuclear Information System (INIS)

    Griffin, G. D.

    1998-01-01

    Unique aspects of the design and construction of two small dams for the Snake Lake Reservoir Project and some of the lessons learned in the process are described. The outstanding feature of this project was that although relatively close together and in the same post-glacial channel, the foundations of the two dams were quite different. The West Dam had permeable silt, sand and gravel with deep bedrock, while the East Dam had impermeable high plastic clay and shallow bedrock as foundation. The challenge to the design was to develop a cross section that would work for both foundation conditions. The final design turned out to be an impermeable fill with toe berms accommodating the variability in the foundations. Instrumentation was used to determine when the second construction stage should commence. At the end of the construction, the reservoir was partially filled relying on the instrumentation to suggest when that would be safe enough to proceed without impacting the overall embankment stability. In the event, the West Dam foundation soils proved to be several orders of magnitude higher than estimated from grain size analyses, requiring installation of a relief valve after construction was completed. Apart from that, dam construction proceeded smoothly and the instrumentation performed as expected.12 refs., 7 figs

  5. Detecting fluid leakage of a reservoir dam based on streaming self-potential measurements

    Science.gov (United States)

    Song, Seo Young; Kim, Bitnarae; Nam, Myung Jin; Lim, Sung Keun

    2015-04-01

    Between many reservoir dams for agriculture in suburban area of South Korea, water leakage has been reported several times. The dam under consideration in this study, which is located in Gyeong-buk, in the south-east of the Korean Peninsula, was reported to have a large leakage at the right foot of downstream side of the reservoir dam. For the detection of the leakage, not only geological survey but also geophysical explorations have been made for precision safety diagnosis, since the leakage can lead to dam failure. Geophysical exploration includes both electrical-resistivity and self-potential surveys, while geological surveys water permeability test, standard penetration test, and sampling for undisturbed sample during the course of the drilling investigation. The geophysical explorations were made not only along the top of dam but also transverse the heel of dam. The leakage of water installations can change the known-heterogeneous structure of the dam body but also cause streaming spontaneous (self) potential (SP) anomaly, which can be detected by electrical resistivity and SP measurements, respectively. For the interpretation of streaming SP, we used trial-and-error method by comparing synthetic SP data with field SP data for model update. For the computation, we first invert the resistivity data to obtain the distorted resistivity structure of the dam levee then make three-dimensional electrical-resistivity modeling for the streaming potential distribution of the dam levee. Our simulation algorithm of streaming SP distribution based on the integrated finite difference scheme computes two-dimensional (2D) SP distribution based on the distribution of calculated flow velocities of fluid for a given permeability structure together with physical properties. This permeability is repeatedly updated based on error between synthetic and field SP data, until the synthetic data match the field data. Through this trial-and-error-based SP interpretation, we locate the

  6. Review on applications of artificial intelligence methods for dam and reservoir-hydro-environment models.

    Science.gov (United States)

    Allawi, Mohammed Falah; Jaafar, Othman; Mohamad Hamzah, Firdaus; Abdullah, Sharifah Mastura Syed; El-Shafie, Ahmed

    2018-05-01

    Efficacious operation for dam and reservoir system could guarantee not only a defenselessness policy against natural hazard but also identify rule to meet the water demand. Successful operation of dam and reservoir systems to ensure optimal use of water resources could be unattainable without accurate and reliable simulation models. According to the highly stochastic nature of hydrologic parameters, developing accurate predictive model that efficiently mimic such a complex pattern is an increasing domain of research. During the last two decades, artificial intelligence (AI) techniques have been significantly utilized for attaining a robust modeling to handle different stochastic hydrological parameters. AI techniques have also shown considerable progress in finding optimal rules for reservoir operation. This review research explores the history of developing AI in reservoir inflow forecasting and prediction of evaporation from a reservoir as the major components of the reservoir simulation. In addition, critical assessment of the advantages and disadvantages of integrated AI simulation methods with optimization methods has been reported. Future research on the potential of utilizing new innovative methods based AI techniques for reservoir simulation and optimization models have also been discussed. Finally, proposal for the new mathematical procedure to accomplish the realistic evaluation of the whole optimization model performance (reliability, resilience, and vulnerability indices) has been recommended.

  7. Water Quality Characteristics of Sembrong Dam Reservoir, Johor, Malaysia

    Science.gov (United States)

    Mohd-Asharuddin, S.; Zayadi, N.; Rasit, W.; Othman, N.

    2016-07-01

    A study of water quality and heavy metal content in Sembrong Dam water was conducted from April - August 2015. A total of 12 water quality parameters and 6 heavy metals were measured and classified based on the Interim National Water Quality Standard of Malaysia (INWQS). The measured and analyzed parameter variables were divided into three main categories which include physical, chemical and heavy metal contents. Physical and chemical parameter variables were temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), turbidity, pH, nitrate, phosphate, ammonium, conductivity and salinity. The heavy metals measured were copper (Cu), lead (Pb), aluminium (Al), chromium (Cr), ferum (Fe) and zinc (Zn). According to INWQS, the water salinity, conductivity, BOD, TSS and nitrate level fall under Class I, while the Ph, DO and turbidity lie under Class IIA. Furthermore, values of COD and ammonium were classified under Class III. The result also indicates that the Sembrong Dam water are not polluted with heavy metals since all heavy metal readings recorded were falls far below Class I.

  8. Geographical Overview of the Three Gorges Dam and Reservoir, China - Geologic Hazards and Environmental Impacts

    Science.gov (United States)

    Highland, Lynn M.

    2008-01-01

    The Three Gorges Dam and Reservoir on the Yangtze River, China, has been an ambitious and controversial project. The dam, the largest in the world as of 2008, will provide hydropower, help to manage flood conditions, and increase the navigability of the Yangtze River. However, this massive project has displaced human and animal populations and altered the stability of the banks of the Yangtze, and it may intensify the seismic hazard of the area. It has also hindered archeological investigations in the reservoir and dam area. This report, originally in the form of a Microsoft PowerPoint presentation, gives a short history and overview of the dam construction and subsequent consequences, especially geologic hazards already noted or possible in the future. The report provides photographs, diagrams, and references for the reader's further research - a necessity, because this great undertaking is dynamic, and both its problems and successes continue to evolve. The challenges and consequences of Three Gorges Dam will be closely watched and documented as lessons learned and applied to future projects in China and elsewhere.

  9. Negligible contribution of reservoir dams to organic and inorganic transport in the lower Mimi River, Japan

    Science.gov (United States)

    Nukazawa, Kei; Kihara, Kousuke; Suzuki, Yoshihiro

    2017-12-01

    Rivers fulfill an essential ecological role by forming networks for material transport from upland forests to coastal areas. The way in which dams affect the organic and inorganic cycles in such systems is not well understood. Herein, we investigated the longitudinal profiles of the various components of the water chemistry across three cascade dams in Japan: the Yamasubaru Dam, Saigou Dam, and Ohuchibaru Dam, which are situated along the sediment-productive Mimi River in different flow conditions. We analyzed the following water quality components: suspended solids (SS), turbidity, total iron (TFe), dissolved iron (DFe), total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), humic substance (HS), and major ionic components (Na+, Mg2+, Ca2+, Cl-, NO3-, and SO42-) in the downstream channels of the three dams during the low-intermediate-flow and high-flow events from 2012 to 2014. We estimated hourly loads of each component using hourly turbidity data and discharge data (i.e., L-Q model) separately, and the results are integrated to estimate the annual fluxes. The annual fluxes between the methods were compared to verify predictability of the conventional L-Q models. Annual flux of TOC, TN, DFe, and HS estimated by the turbidity displayed similar values, whereas the flux of SS, TFe, and TP tended to increase downstream of the dams. Among the dams, estimated flux proportions for TP and TFe were higher during high-flow events (74%-94%). Considering geographic conditions (e.g., absence of major tributary between the dams), the result implies that accumulated TP and TFe in the reservoirs may be flushed and transported downstream with SS over the short height dams during flood events. Assuming this process, the reservoir dams probably make only a fractional contribution to the organic and inorganic transport in the catchment studied. The percent flux errors for SS, TFe, and TP fluxes ranged from -7.2% to -97% (except for the TP flux in 2013), which

  10. Characterization of transient groundwater flow through a high arch dam foundation during reservoir impounding

    Directory of Open Access Journals (Sweden)

    Yifeng Chen

    2016-08-01

    Full Text Available Even though a large number of large-scale arch dams with height larger than 200 m have been built in the world, the transient groundwater flow behaviors and the seepage control effects in the dam foundations under difficult geological conditions are rarely reported. This paper presents a case study on the transient groundwater flow behaviors in the rock foundation of Jinping I double-curvature arch dam, the world's highest dam of this type to date that has been completed. Taking into account the geological settings at the site, an inverse modeling technique utilizing the time series measurements of both hydraulic head and discharge was adopted to back-calculate the permeability of the foundation rocks, which effectively improves the uniqueness and reliability of the inverse modeling results. The transient seepage flow in the dam foundation during the reservoir impounding was then modeled with a parabolic variational inequality (PVI method. The distribution of pore water pressure, the amount of leakage, and the performance of the seepage control system in the dam foundation during the entire impounding process were finally illustrated with the numerical results.

  11. Numerical Simulations of Spread Characteristics of Toxic Cyanide in the Danjiangkou Reservoir in China under the Effects of Dam Cooperation

    Directory of Open Access Journals (Sweden)

    Libin Chen

    2014-01-01

    Full Text Available Many accidents of releasing toxic pollutants into surface water happen each year in the world. It is believed that dam cooperation can affect flow field in reservoir and then can be applied to avoiding and reducing spread speed of toxic pollutants to drinking water intake mouth. However, few studies investigated the effects of dam cooperation on the spread characteristics of toxic pollutants in reservoir, especially the source reservoir for water diversion with more than one dam. The Danjiangkou Reservoir is the source reservoir of the China’ South-to-North Water Diversion Middle Route Project. The human activities are active within this reservoir basin and cyanide-releasing accident once happened in upstream inflow. In order to simulate the spread characteristics of cyanide in the reservoir in the condition of dam cooperation, a three-dimensional water quality model based on the Environmental Fluid Dynamics Code (EFDC has been built and put into practice. The results indicated that cooperation of two dams of the Danjiangkou Reservoir could be applied to avoiding and reducing the spread speed of toxic cyanide in the reservoir directing to the water intake mouth for water diversions.

  12. National Dam Safety Program. Lindys Lake Dam (NJ00201), Passaic River Basin, Branch of West Brook, Passaic County, New Jersey. Phase 1 Inspection Report.

    Science.gov (United States)

    1980-02-01

    shallow ground moraine over rock. The downstream channel is described as swamp. The rock is described on Geologic Overlay Sheet 22, as hornblende granite ...DAM 410-04’ hqa Scale: I" =I Mite LEGEND: PRECAMBRIAN gh Mostly Hornblende Granite and Gneiss. hqa Hyperstene-Quartz- And esine.-Gneiss. GEOLOGIC MAP L...A.J. 0o2o/) S CZ6 -§&S5 /,r/ C,4 7-1 ,4V-etaoe Dep4e&/LaL L* rt~~~c~~t4’A aeS’ OP~ ~ A AI 3CD PS?7V7,/ & zAer ’, ! v’.’:7- z - 6 c ,, ,, ,,g

  13. Examination of dam induced sedimentation of small reservoir near Brennbergbánya

    Science.gov (United States)

    Csáfordi, P.; Kalicz, P.; Gribovszki, Z.; Kucsara, M.

    2009-04-01

    The dams' affects on the stream system also involve accelerated sedimentation of reservoirs, change of water and sediment regime. In consequence of sedimentation the lifetime and the recreational potential of reservoirs decrease and management practices have to be applied. The area of our study is a small forested catchment, where the erosion of forested land and the sedimentation of Brennberg Reservoir were investigated in relationship with each other. The Brennberg Reservoir has been built in 1981. It has been silting up forcefully since that time. It has to be dredged with hydraulic earth-moving to preserve its landscape-aesthetical function for the future. We have surveyed the surface to establish the rate of sedimentation. The results of this measurement were processed with a GIS software (named Digiterra Map). There were several uncertainties during our surveying in the field. Therefore three other methods were applied based on GIS and a simply mathematical calculation. The amount of deposited sediment was determined with these methods. Then we compared the results to each other. The annual specific soil loss was estimated according to results of our measurement. Keywords: dam impact, reservoir sedimentation, GIS

  14. Forward modeling of seepage of reservoir dam based on ground penetrating radar

    Directory of Open Access Journals (Sweden)

    Xueli WU

    2017-08-01

    Full Text Available The risk of the reservoir dam seepage will bring the waste of water resources and the loss of life and property. The ground penetrating radar (GPR is designed as a daily inspection system of dams to improve the existing technology which can't determine the actual situation of the dam seepage tunnel coordinates. The finite difference time domain (FDTD is used to solve the Yee's grids discreatization in two-dimensional space, and its electromagnetic distribution equation is obtained as well. Based on the actual structure of reservoir dam foundation, the ideal model of air layer, concrete layer, clay layer and two water seepage holes is described in detail, and the concrete layer interference model with limestone interference point is established. The system architecture is implemented by using MATLAB, and the forward modeling is performed. The results indicate that ground penetrating radar can be used for deep target detection. Through comparing the detection spectrum of three kinds of frequency electromagnetic wave by changing the center frequency of the GPR electromagnetic wave of 50 MHz, 100 MHz and 200 MHz, it is concluded that the scanning result is more accurate at 100 MHz. At the same time, the simulation results of the interference model show that this method can be used for the detection of complex terrain.

  15. Reservoir stratification affects methylmercury levels in river water, plankton, and fish downstream from Balbina hydroelectric dam, Amazonas, Brazil.

    Science.gov (United States)

    Kasper, Daniele; Forsberg, Bruce R; Amaral, João H F; Leitão, Rafael P; Py-Daniel, Sarah S; Bastos, Wanderley R; Malm, Olaf

    2014-01-21

    The river downstream from a dam can be more contaminated by mercury than the reservoir itself. However, it is not clear how far the contamination occurs downstream. We investigated the seasonal variation of methylmercury levels in the Balbina reservoir and how they correlated with the levels encountered downstream from the dam. Water, plankton, and fishes were collected upstream and at sites between 0.5 and 250 km downstream from the dam during four expeditions in 2011 and 2012. Variations in thermal stratification of the reservoir influenced the methylmercury levels in the reservoir and in the river downstream. Uniform depth distributions of methylmercury and oxygen encountered in the poorly stratified reservoir during the rainy season collections coincided with uniformly low methylmercury levels along the river downstream from the dam. During dry season collections, the reservoir was strongly stratified, and anoxic hypolimnion water with high methylmercury levels was exported downstream. Methylmercury levels declined gradually to 200 km downstream. In general, the methylmercury levels in plankton and fishes downstream from the dam were higher than those upstream. Higher methylmercury levels observed 200-250 km downstream from the dam during flooding season campaigns may reflect the greater inflow from tributaries and flooding of natural wetlands that occurred at this time.

  16. Economic and social importance of dam reservoirs – a study of the Soła River cascade

    Directory of Open Access Journals (Sweden)

    Andrzej Jaguś

    2018-02-01

    Full Text Available The paper is devoted to the functions of dam reservoirs in terms of their socioeconomic usefulness. Three dam reservoirs of the Soła cascade were chosen (Tresna, Porąbka, Czaniec as the example that are located in the southern part of Silesian Provence. The cascade is an integrated retention system, but particular reservoirs have different functions. The role of reservoirs in flood protection (Tresna, Porąbka, drinking water supply (Czaniec, electricity production (Porąbka/Porąbka-Żar, recreation (Porąbka, Tresna, supply of rock aggregate (Tresna was depicted as well. The high importance of the cascade for economic development of the region was demonstrated. Finally, the controversies about the construction and utility of dam reservoirs were discussed.

  17. Dam! Dam! Dam!

    International Nuclear Information System (INIS)

    McCully, P.

    1997-01-01

    The author of ''Silenced Rivers'' a book questioning the desirability of dam building and hydroelectric power generation argues the main themes of his book in this paper. Despite being hailed by politicians as good solutions to power generation problems, and enthusiastically pursued in China, the U.S.A., the former Soviet Union, India and Japan, dams have far-reaching ecological and human consequences. The ecosystems lost to flooding, and the agricultural land use lost, the human cost in terms of homes and employment lost to reservoirs, disease from water-borne infections such as malaria, and the hazards of dams overflowing or breaking are all factors which are against the case for dam construction. The author argues the hydroelectric power may be renewable, but the social, agricultural and ecological costs are too high to justify it as a method of first choice. (UK)

  18. Dams

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset �is generated from from the Vermont Dam Inventory (VDI). The VDI is managed by the VT DEC's Dam Safety and Hydrology Section and contains information...

  19. Determination of geostatistically representative sampling locations in Porsuk Dam Reservoir (Turkey)

    Science.gov (United States)

    Aksoy, A.; Yenilmez, F.; Duzgun, S.

    2013-12-01

    Several factors such as wind action, bathymetry and shape of a lake/reservoir, inflows, outflows, point and diffuse pollution sources result in spatial and temporal variations in water quality of lakes and reservoirs. The guides by the United Nations Environment Programme and the World Health Organization to design and implement water quality monitoring programs suggest that even a single monitoring station near the center or at the deepest part of a lake will be sufficient to observe long-term trends if there is good horizontal mixing. In stratified water bodies, several samples can be required. According to the guide of sampling and analysis under the Turkish Water Pollution Control Regulation, a minimum of five sampling locations should be employed to characterize the water quality in a reservoir or a lake. The European Union Water Framework Directive (2000/60/EC) states to select a sufficient number of monitoring sites to assess the magnitude and impact of point and diffuse sources and hydromorphological pressures in designing a monitoring program. Although existing regulations and guidelines include frameworks for the determination of sampling locations in surface waters, most of them do not specify a procedure in establishment of monitoring aims with representative sampling locations in lakes and reservoirs. In this study, geostatistical tools are used to determine the representative sampling locations in the Porsuk Dam Reservoir (PDR). Kernel density estimation and kriging were used in combination to select the representative sampling locations. Dissolved oxygen and specific conductivity were measured at 81 points. Sixteen of them were used for validation. In selection of the representative sampling locations, care was given to keep similar spatial structure in distributions of measured parameters. A procedure was proposed for that purpose. Results indicated that spatial structure was lost under 30 sampling points. This was as a result of varying water

  20. A coupled FE and scaled boundary FE-approach for the earthquake response analysis of arch dam-reservoir-foundation system

    International Nuclear Information System (INIS)

    Wang Yi; Lin Gao; Hu Zhiqiang

    2010-01-01

    For efficient and accurate modelling of arch dam-reservoir-foundation system a coupled Finite Element method (FEM) and Scaled Boundary Finite Element method (SBFEM) is developed. Both the dam-foundation interaction and the dam-reservoir interaction including the effect of reservoir boundary absorption are taken into account. The arch dam is modelled by FEM, while the reservoir domain and the unbounded foundation are modelled by SBFEM. In order to make comparison with the results available in the literature, the Morrow Point arch dam is selected for numerical analysis. The analyses are carried out in the frequency domain, and then the time-domain response of the dam-reservoir-foundation system is obtained by Inverse Fourier Transform.

  1. Finite Element Analysis of Dam-Reservoir Interaction Using High-Order Doubly Asymptotic Open Boundary

    Directory of Open Access Journals (Sweden)

    Yichao Gao

    2011-01-01

    Full Text Available The dam-reservoir system is divided into the near field modeled by the finite element method, and the far field modeled by the excellent high-order doubly asymptotic open boundary (DAOB. Direct and partitioned coupled methods are developed for the analysis of dam-reservoir system. In the direct coupled method, a symmetric monolithic governing equation is formulated by incorporating the DAOB with the finite element equation and solved using the standard time-integration methods. In contrast, the near-field finite element equation and the far-field DAOB condition are separately solved in the partitioned coupled methodm, and coupling is achieved by applying the interaction force on the truncated boundary. To improve its numerical stability and accuracy, an iteration strategy is employed to obtain the solution of each step. Both coupled methods are implemented on the open-source finite element code OpenSees. Numerical examples are employed to demonstrate the performance of these two proposed methods.

  2. Flood hydrology and dam-breach hydraulic analyses of four reservoirs in the Black Hills, South Dakota

    Science.gov (United States)

    Hoogestraat, Galen K.

    2011-01-01

    Extensive information about the construction of dams or potential downstream hazards in the event of a dam breach is not available for many small reservoirs within the Black Hills National Forest. In 2009, the U.S. Forest Service identified the need for reconnaissance-level dam-breach assessments for four of these reservoirs within the Black Hills National Forest (Iron Creek, Horsethief, Lakota, and Mitchell Lakes) with the potential to flood downstream structures. Flood hydrology and dam-breach hydraulic analyses for the four selected reservoirs were conducted by the U.S. Geological Survey in cooperation with the U.S. Forest service to estimate the areal extent of downstream inundation. Three high-flow breach scenarios were considered for cases when the dam is in place (overtopped) and when a dam break (failure) occurs: the 100-year recurrence 24-hour precipitation, 500-year recurrence peak flow, and the probable maximum precipitation. Inundation maps were developed that show the estimated extent of downstream floodwaters from simulated scenarios. Simulation results were used to determine the hazard classification of a dam break (high, significant, or low), based primarily on the potential for loss of life or property damage resulting from downstream inundation because of the flood surge.The inflow design floods resulting from the two simulated storm events (100-year 24-hour and probable maximum precipitation) were determined using the U.S. Army Corps of Engineers Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS). The inflow design flood for the 500-year recurrence peak flow was determined by using regional regression equations developed for streamflow-gaging stations with similar watershed characteristics. The step-backwater hydraulic analysis model, Hydrologic Engineering Center's River Analysis System (HEC-RAS), was used to determine water-surface profiles of in-place and dam-break scenarios for the three inflow design floods that were

  3. Billy Shaw Dam and Reservoir: Environmental assessment and finding of no significant impacts

    International Nuclear Information System (INIS)

    1997-03-01

    This notice announces BPA's decision to fund the construction, operation, and maintenance of the Billy Shaw Dam and Reservoir on the Duck Valley Reservation. This project is part of a continuing effort to address system-wide fish and wildlife losses caused by the development of the hydropower system in the Columbia River Basin. BPA has prepared an Environmental Assessment (EA) evaluating the potential environmental impacts of the proposed project. Based on the analysis in the EA, BPA has determined that the Proposed Action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and BPA is issuing this FONSI

  4. Billy Shaw Dam and Reservoir : Environmental Assessment and Finding of No Significant Impacts.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration; Shoshone-Paiute Tribes of the Duck Valley Reservation, Nevada.

    1997-03-01

    This notice announces BPA`s decision to fund the construction, operation, and maintenance of the Billy Shaw Dam and Reservoir on the Duck Valley Reservation. This project is part of a continuing effort to address system-wide fish and wildlife losses caused by the development of the hydropower system in the Columbia River Basin. BPA has prepared an Environmental Assessment (EA) evaluating the potential environmental impacts of the proposed project. Based on the analysis in the EA, BPA has determined that the Proposed Action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and BPA is issuing this FONSI.

  5. 3-D CFD simulations of hydrodynamics in the Sulejow dam reservoir

    Directory of Open Access Journals (Sweden)

    Ziemińska-Stolarska Aleksandra

    2015-12-01

    Full Text Available This paper reports the processes by which a single-phase 3-D CFD model of hydrodynamics in a 17-km-long dam reservoir was developed, verified and tested. A simplified VOF model of flow was elaborated to determine the effect of wind on hydrodynamics in the lake. A hexahedral mesh with over 17 million elements and a k-ω SST turbulence model were defined for single-phase simulations in steady-state conditions. The model was verified on the basis of the extensive flow measurements (StreamPro ADCP, USA. Excellent agreement (average error of less than 10% between computed and measured velocity profiles was found. The simulation results proved a strong effect of wind on hydrodynamics in the lake, especially on the development of the water circulation pattern in the lacustrine zone.

  6. Landslide-Generated Waves in a Dam Reservoir: The Effects of Landslide Rheology and Initial Submergence

    Science.gov (United States)

    Yavari Ramsheh, S.; Ataie-Ashtiani, B.

    2017-12-01

    Recent studies revealed that landslide-generated waves (LGWs) impose the largest tsunami hazard to our shorelines although earthquake-generated waves (EGWs) occur more often. Also, EGWs are commonly followed by a large number of landslide hazards. Dam reservoirs are more vulnerable to landslide events due to being located in mountainous areas. Accurate estimation of such hazards and their destructive consequences help authorities to reduce their risks by constructive measures. In this regard, a two-layer two-phase Coulomb mixture flow (2LCMFlow) model is applied to investigate the effects of landslide characteristics on LGWs for a real-sized simplification of the Maku dam reservoir, located in the North of Iran. A sensitivity analysis is performed on the role of landslide rheological and constitutive parameters and its initial submergence in LGW characteristics and formation patterns. The numerical results show that for a subaerial (SAL), a semi-submerged (SSL), and a submarine landslide (SML) with the same initial geometry, the SSLs can create the largest wave crest, up to 60% larger than SALs, for dense material. However, SMLs generally create the largest wave troughs and SALs travel the maximum runout distances beneath the water. Regarding the two-phase (solid-liquid) nature of the landslide, when interestial water is isolated from the water layer along the water/landslide interface, a LGW with up to 30% higher wave crest can be created. In this condition, increasing the pore water pressure within the granular layer results in up to 35% higher wave trough and 40% lower wave crest at the same time. These results signify the importance of appropriate description of two-phase nature and rheological behavior of landslides in accurate estimation of LGWs which demands further numerical, physical, and field studies about such phenomena.

  7. Displacement response of a concrete arch dam to seasonal temperature fluctuations and reservoir level rise during the first filling period: evidence from geodetic data

    Directory of Open Access Journals (Sweden)

    Cemal Ozer Yigit

    2016-07-01

    Full Text Available The present study evaluates the dynamic behaviour of the Ermenek Dam, the second highest dam in Turkey, based on conventional geodetic measurements and Finite Element Model (FEM analyses during its first filling period. In total, eight periods of measured deformation are considered from the end of construction until the reservoir reached its full capacity. The displacement response of the dam to the reservoir level and to seasonal temperature variations is examined in detail. Time series of apparent total displacements at the middle of the crest of the dam exhibits periodicity and linear trends. Correlation analysis revealed that periodic and linear displacement responses of the dam are related to variations of seasonal temperature and linearly increased reservoir level, respectively, indicating a relation between temperature, water load and dam deformation. It is also concluded that measured deformations based on geodetic data show good agreement with the predicted deformation obtained by the FEM analysis.

  8. Survival estimates for the passage of juvenile salmonids through Snake River dams and reservoirs, 1996. Annual report

    International Nuclear Information System (INIS)

    Smith, S.G.; Muir, W.D.; Hockersmith, E.E.; Achord, S.; Eppard, M.B.; Ruehle, T.E.; Williams, J.G.

    1998-02-01

    In 1996, the National Marine Fisheries Service and the University of Washington completed the fourth year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake River. Actively migrating smolts were collected near the head of Lower Granite Reservoir and at Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Individual smolts were subsequently detected at PIT-tag detection facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day and Bonneville Dams. Survival estimates were calculated using the Single-Release (SR) and Paired-Release (PR) Models. Timing of releases of tagged hatchery steelhead (O. mykiss) from the head of Lower Granite Reservoir and yearling chinook salmon (O. tshawytscha) from Lower Granite Dam in 1996 spanned the major portion of their juvenile migrations. Specific research objectives in 1996 were to (1) estimate reach and project survival in the Snake River using the Single-Release and Paired-Release Models throughout the yearling chinook salmon and steelhead migrations, (2) evaluate the performance of the survival-estimation models under prevailing operational and environmental conditions in the Snake River, and (3) synthesize results from the 4 years of the study to investigate relationships between survival probabilities, travel times, and environmental factors such as flow levels and water temperature

  9. Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1996 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.

    1998-02-01

    In 1996, the National Marine Fisheries Service and the University of Washington completed the fourth year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake River. Actively migrating smolts were collected near the head of Lower Granite Reservoir and at Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Individual smolts were subsequently detected at PIT-tag detection facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day and Bonneville Dams. Survival estimates were calculated using the Single-Release (SR) and Paired-Release (PR) Models. Timing of releases of tagged hatchery steelhead (O. mykiss) from the head of Lower Granite Reservoir and yearling chinook salmon (O. tshawytscha) from Lower Granite Dam in 1996 spanned the major portion of their juvenile migrations. Specific research objectives in 1996 were to (1) estimate reach and project survival in the Snake River using the Single-Release and Paired-Release Models throughout the yearling chinook salmon and steelhead migrations, (2) evaluate the performance of the survival-estimation models under prevailing operational and environmental conditions in the Snake River, and (3) synthesize results from the 4 years of the study to investigate relationships between survival probabilities, travel times, and environmental factors such as flow levels and water temperature.

  10. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    increase in hatchery Chinook catch in 2002 was due to a 3.1 fold increase in hatchery production and differences in flow between years. Changes in hatchery and wild steelhead catch are probably due to differences in flow between years. Travel time (d) and migration rate (km/d) through Lower Granite Reservoir for PIT-tagged Chinook salmon and steelhead trout marked at the Snake River trap were affected by discharge. Statistical analysis of 2002 data detected a relation between migration rate and discharge for hatchery and wild Chinook salmon. For hatchery and wild Chinook salmon there was a 4.7-fold and a 3.7-fold increase in migration rate, respectively, between 50 and 100 kcfs. For steelhead trout tagged at the Snake River trap, statistical analysis detected a significant relation between migration rate and Lower Granite Reservoir inflow discharge. For hatchery and wild steelhead trout, there was a 1.8-fold and a 1.7-fold increase in migration rate, respectively, between 50 and 100 kcfs. Travel time and migration rate to Lower Granite Dam for fish marked at the Salmon River trap were calculated. Statistical analysis of the 2002 data detected a significant relation between migration rate and Lower Granite Reservoir inflow discharge for wild Chinook salmon and hatchery steelhead trout. The analysis was unable to detect a relation between migration rate and discharge for hatchery Chinook salmon. The lack of a detectable relation was probably a result of the migration rate data being spread over a very narrow range of discharge. Not enough data were available to perform the analysis for wild steelhead trout. Migration rate increased 4.3-fold for wild Chinook salmon and 2.2-fold for hatchery steelhead between 50 kcfs and 100 kcfs. Fish tagged with passive integrated transponder (PIT) tags at the Snake River trap were interrogated at four dams with PIT tag detection systems (Lower Granite, Little Goose, Lower Monumental, and McNary dams). Because of the addition of the fourth

  11. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    flows. There were zero days when the trap was out of operation due to high flow or debris. The decrease in hatchery Chinook catch in 2003 was partially due to differences in flow between years because there was a 5.9% increase in hatchery production in the Salmon River drainage in 2003. The decrease in hatchery steelhead catch may be partially due to a 13% decrease in hatchery production in the Salmon River drainage in 2003. Travel time (d) and migration rate (km/d) through Lower Granite Reservoir for PIT-tagged Chinook salmon and steelhead trout marked at the Snake River trap were affected by discharge. Statistical analysis of 2003 data detected a relation between migration rate and discharge for wild Chinook salmon but was unable to detect a relation for hatchery Chinook. The inability to detect a migration rate discharge relation for hatchery Chinook was probably caused by age 0 fall Chinook being mixed in with the age 1 Chinook. Age 0 fall Chinook migrate much slower than age 1 Chinook, which would confuse the ability to detect the migration rate discharge relation. For wild Chinook salmon there was a 1.4-fold increase in migration rate, respectively, between 50 and 100 kcfs. For steelhead trout tagged at the Snake River trap, statistical analysis detected a significant relation between migration rate and Lower Granite Reservoir inflow discharge. For hatchery and wild steelhead trout, there was a 1.7-fold and a 1.9-fold increase in migration rate, respectively, between 50 and 100 kcfs. Travel time and migration rate to Lower Granite Dam for fish marked at the Salmon River trap were calculated. Statistical analysis of the 2003 data detected a significant relation between migration rate and Lower Granite Reservoir inflow discharge for hatchery Chinook salmon, wild Chinook salmon and hatchery steelhead trout. Not enough data were available to perform the analysis for wild steelhead trout. Migration rate increased 14-fold for hatchery Chinook salmon, 8.3-fold for wild

  12. Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Muir, William D.

    1995-02-01

    In 1994, the National Marine Fisheries Service and the University of Washington completed the second year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through the dams and reservoirs of the Snake River. Actively migrating smolts were collected at selected locations above, at, and below Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Survival estimates were calculated using the Single-Release, Modified Single-Release, and Paired-Release Models.

  13. National Program for Inspection of Non-Federal Dams. Lower Reservoir Dam (NH 00048), NHWRB Number 108.05, Connecticut River Basin, Hanover, New Hampshire. Phase I Inspection Report.

    Science.gov (United States)

    1979-11-01

    reservoirs, Upper Reservoir and Reservoir No. 3. The reservoir supplies to the water destribution system by gravity. h. Design and Construction History. o...continual supply to the water , destribution system as the main service area is fed by gravity. The waste pipe is usually closed. The flashboards on...however, no design calculations or b construction data were revealed.. The visual inspection revealed that the dam is in poor condition. The visual

  14. Estimating the Optimal Capacity for Reservoir Dam based on Reliability Level for Meeting Demands

    Directory of Open Access Journals (Sweden)

    Mehrdad Taghian

    2017-02-01

    Full Text Available Introduction: One of the practical and classic problems in the water resource studies is estimation of the optimal reservoir capacity to satisfy demands. However, full supplying demands for total periods need a very high dam to supply demands during severe drought conditions. That means a major part of reservoir capacity and costs is only usable for a short period of the reservoir lifetime, which would be unjustified in economic analysis. Thus, in the proposed method and model, the full meeting demand is only possible for a percent time of the statistical period that is according to reliability constraint. In the general methods, although this concept apparently seems simple, there is a necessity to add binary variables for meeting or not meeting demands in the linear programming model structures. Thus, with many binary variables, solving the problem will be time consuming and difficult. Another way to solve the problem is the application of the yield model. This model includes some simpler assumptions and that is so difficult to consider details of the water resource system. The applicationof evolutionary algorithms, for the problems have many constraints, is also very complicated. Therefore, this study pursues another solution. Materials and Methods: In this study, for development and improvement the usual methods, instead of mix integer linear programming (MILP and the above methods, a simulation model including flow network linear programming is used coupled with an interface manual code in Matlab to account the reliability based on output file of the simulation model. The acre reservoir simulation program (ARSP has been utilized as a simulation model. A major advantage of the ARSP is its inherent flexibility in defining the operating policies through a penalty structure specified by the user. The ARSP utilizes network flow optimization techniques to handle a subset of general linear programming (LP problems for individual time intervals

  15. Bursting Events in Pressure Flushing with Expanding Bottom Outlet Channel within Dam Reservoir

    Directory of Open Access Journals (Sweden)

    soheila Tofighi

    2017-01-01

    Full Text Available Introduction: Currently, large dams in the world, due to the high amount of sediments in the reservoir, especially around the intake, have operational problems. One of the solutions for this problem is pressure flushing. In this type of flushing, a mixture of water and sediment is removed from bottom outlets form dam reservoir and a funnel shaped crater is created in the vicinity of the outlet opening. In laboratory experiments carried out in this study, pressure flushing with the expansion of bottom outlet within the reservoir and its statistical analysis of bursting events were investigated. The structure of the turbulent flow is not fully understood due to their complexity and random nature. Klein et al. Introduced the turbulence bursting in this kind of flow and Nezo and Nakagora suggested that the events resulting from turbulence bursting has a significant effect of transferring the sediment particles. Materials and Methods: For the purposes of this study, the experiments were conducted with a physical model with 7m length, 1.4m width, and 1.5m height, consisting of three parts namely the inlet of the model, the main reservoir, and settling basin. The main reservoir of the model was 5m long and the sediments were placed within this part of the model. The sediment particles were non-cohesive silica with uniform size and with median diameter (d50 1.15mm and geometrics standard deviation (σg 1.37. Experiments carried out with different discharges and water depths above the bottom outlet in different expansion size of outlet channel in constant sediment level of 20cm above the center of the outlet channel. The model was slowly filled with water until the water surface elevation reached to a desired level. The bottom outlet was manually opened, after a while sedimentwere discharged with the water flow in very high concentrations through the outlet channel (sudden discharge and a funnel shaped crater was formed in front of it. After the run of

  16. Reservoir Operation Rules for Controlling Algal Blooms in a Tributary to the Impoundment of Three Gorges Dam

    Directory of Open Access Journals (Sweden)

    Jijian Lian

    2014-10-01

    Full Text Available Since the first impoundment of Three Gorges Dam in 2003, algal blooms occur frequently in the near-dam tributaries. It is widely recognized that the impoundment-induced change in hydrodynamic condition with the lower current velocity will make the eutrophication problem even more severe when an excessive amount of nutrients is already loaded into a reservoir and/or its tributaries. Operation tests carried out by Three Gorges Corporation in 2010 point to some feasible reservoir operation schemes that may have positive impacts on reducing the algal bloom level. In our study, an attempt is made to obtain, through a numerical hydrodynamic and water quality modeling and analysis, the reservoir operation rules that would reduce the level of algal blooms in the Xiangxi River (XXR, a near-dam tributary. Water movements and algal blooms in XXR are simulated and analyzed under different scenarios of one-day water discharge fluctuation or two-week water level variation. The model results demonstrate that the reservoir operations can further increase the water exchange between the mainstream of the Three Gorges Reservoir (TGR and the XXR tributary and thus move a larger amount of algae into the deep water where it will die. Analysis of the model results indicate that the water discharge fluctuation constituted of a lower valley-load flow and a larger flow difference for the short-term operation (within a day, the rise in water level for the medium-term operation (e.g., over weeks, and the combination of the above two for the long-term operation (e.g., over months can be the feasible reservoir operation rules in the non-flood season for TGR.

  17. Energy dissipation by submarine obstacles during landslide impact on reservoir - potentially avoiding catastrophic dam collapse

    Science.gov (United States)

    Kafle, Jeevan; Kattel, Parameshwari; Mergili, Martin; Fischer, Jan-Thomas; Tuladhar, Bhadra Man; Pudasaini, Shiva P.

    2017-04-01

    Dense geophysical mass flows such as landslides, debris flows and debris avalanches may generate super tsunami waves as they impact water bodies such as the sea, hydraulic reservoirs or mountain lakes. Here, we apply a comprehensive and general two-phase, physical-mathematical mass flow model (Pudasaini, 2012) that consists of non-linear and hyperbolic-parabolic partial differential equations for mass and momentum balances, and present novel, high-resolution simulation results for two-phase flows, as a mixture of solid grains and viscous fluid, impacting fluid reservoirs with obstacles. The simulations demonstrate that due to the presence of different obstacles in the water body, the intense flow-obstacle-interaction dramatically reduces the flow momentum resulting in the rapid energy dissipation around the obstacles. With the increase of obstacle height overtopping decreases but, the deflection and capturing (holding) of solid mass increases. In addition, the submarine solid mass is captured by the multiple obstacles and the moving mass decreases both in amount and speed as each obstacle causes the flow to deflect into two streams and also captures a portion of it. This results in distinct tsunami and submarine flow dynamics with multiple surface water and submarine debris waves. This novel approach can be implemented in open source GIS modelling framework r.avaflow, and be applied in hazard mitigation, prevention and relevant engineering or environmental tasks. This might be in particular for process chains, such as debris impacts in lakes and subsequent overtopping. So, as the complex flow-obstacle-interactions strongly and simultaneously dissipate huge energy at impact such installations potentially avoid great threat against the integrity of the dam. References: Pudasaini, S. P. (2012): A general two-phase debris flow model. J. Geophys. Res. 117, F03010, doi: 10.1029/ 2011JF002186.

  18. Survival estimates for the passage of juvenile chinook salmon through Snake River dams and reservoirs. Annual report 1993

    International Nuclear Information System (INIS)

    Iwamoto, R.N.; Muir, W.D.; Sandford, B.P.; McIntyre, K.W.; Frost, D.A.; Williams, J.G.; Smith, S.G.; Skalski, J.R.

    1994-04-01

    A pilot study was conducted to estimate survival of hatchery-reared yearling chinook salmon through dams and reservoirs on the Snake River. The goals of the study were to: (1) field test and evaluate the Single-Release, Modified-Single-Release, and Paired-Release Models for the estimation of survival probabilities through sections of a river and hydroelectric projects; (2) identify operational and logistical constraints to the execution of these models; and (3) determine the usefulness of the models in providing estimates of survival probabilities. Field testing indicated that the numbers of hatchery-reared yearling chinook salmon needed for accurate survival estimates could be collected at different areas with available gear and methods. For the primary evaluation, seven replicates of 830 to 1,442 hatchery-reared yearling chinook salmon were purse-seined from Lower Granite Reservoir, PIT tagged, and released near Nisqually John boat landing (River Kilometer 726). Secondary releases of PIT-tagged smolts were made at Lower Granite Dam to estimate survival of fish passing through turbines and after detection in the bypass system. Similar secondary releases were made at Little Goose Dam, but with additional releases through the spillway. Based on the success of the 1993 pilot study, the authors believe that the Single-Release and Paired-Release Models will provide accurate estimates of juvenile salmonid passage survival for individual river sections, reservoirs, and hydroelectric projects in the Columbia and Snake Rivers

  19. Survival Estimates for the Passage of Juvenile Chinook Salmon through Snake River Dams and Reservoirs, 1993 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Robert N.; Sandford, Benjamin P.; McIntyre, Kenneth W.

    1994-04-01

    A pilot study was conducted to estimate survival of hatchery-reared yearling chinook salmon through dams and reservoirs on the Snake River. The goals of the study were to: (1) field test and evaluate the Single-Release, Modified-Single-Release, and Paired-Release Models for the estimation of survival probabilities through sections of a river and hydroelectric projects; (2) identify operational and logistical constraints to the execution of these models; and (3) determine the usefulness of the models in providing estimates of survival probabilities. Field testing indicated that the numbers of hatchery-reared yearling chinook salmon needed for accurate survival estimates could be collected at different areas with available gear and methods. For the primary evaluation, seven replicates of 830 to 1,442 hatchery-reared yearling chinook salmon were purse-seined from Lower Granite Reservoir, PIT tagged, and released near Nisqually John boat landing (River Kilometer 726). Secondary releases of PIT-tagged smolts were made at Lower Granite Dam to estimate survival of fish passing through turbines and after detection in the bypass system. Similar secondary releases were made at Little Goose Dam, but with additional releases through the spillway. Based on the success of the 1993 pilot study, the authors believe that the Single-Release and Paired-Release Models will provide accurate estimates of juvenile salmonid passage survival for individual river sections, reservoirs, and hydroelectric projects in the Columbia and Snake Rivers.

  20. SILTATION AND EROSION PROCESSES ON A TRIBUTARY OF LAKE ITAIPU DUE A DAM RESERVOIR

    Directory of Open Access Journals (Sweden)

    Cristiano Poleto

    2012-12-01

    creating an imbalance between the small amount of sediment transported after the hydroelectric and flow transport capacity. There are two cases occurring in a dam: 1 the dam upstream has a reduction of velocity and it start a process of sedimentation that will accelerate its siltation and reducing its useful life, 2 dam downstream has water velocity again and then initiate erosion process due the lack of sediments in the liquid mass. It can be concluded that changes of use and occupation of land in the watershed generate increased occurrence of peak flow and sediment transport, but the inadequate management of the area (with removal of riparian vegetation and lack of energy sinks in outputs of drainage systems potentiates the increasing the instability of water bodies morphology. In case of presence of reservoirs, the alterations are worst because they create siltation and erosion process at the same river.

  1. Coordinate reduction for the seismic analysis of dam-foundation-reservoir systems with non-proportional damping

    International Nuclear Information System (INIS)

    Mehai, L.; Paultre, P.; Leger, P.

    1992-01-01

    In the design of dams to withstand seismic events, recent studies have shown that the dam-foundation and dam-reservoir interactions have a significant influence on the dynamic response of the dam. The hypothesis of proportional damping is not realistic for such structures, in which the mechanisms of energy dissipation present notable differences between their various components. A comparative study is presented of different methods of resolution of linear systems with non-proportional damping, using recent techniques of coordinate reduction. Parametric studies were conducted on a 2-dimensional finite element model of a concrete gravity dam-foundation system. The comparison focuses essentially on the numerical efficiency and precision in the calculation of dynamic parameters (displacements, accelerations, and internal stresses) and in the distribution of damping energy among the components of the system. The evaluation of the energy dissipated in the absorbing boundaries has indicated that the algorithms retained for reducing the coordinates in real and complex space conveniently model the conditions at the limits of the structure. The high degree of numerical stability and the efficiency of the interative procedure of Ibrahimbegovic and Wilson (1989), applied to systems with a large number of degrees of freedom, has been confirmed. 10 refs., 8 figs

  2. Evaluation of uncertainty in dam-break analysis resulting from dynamic representation of a reservoir; Evaluation de l'incertitude due au modele de representation du reservoir dans les analyses de rupture de barrage

    Energy Technology Data Exchange (ETDEWEB)

    Tchamen, G.W.; Gaucher, J. [Hydro-Quebec Production, Montreal, PQ (Canada). Direction Barrage et Environnement, Unite Barrages et Hydraulique

    2010-08-15

    Owners and operators of high capacity dams in Quebec have a legal obligation to conduct dam break analysis for each of their dams in order to ensure public safety. This paper described traditional hydraulic methodologies and models used to perform dam break analyses. In particular, it examined the influence of the reservoir drawdown submodel on the numerical results of a dam break analysis. Numerical techniques from the field of fluid mechanics and aerodynamics have provided the basis for developing effective hydrodynamic codes that reduce the level of uncertainties associated with dam-break analysis. A static representation that considers the storage curve was compared with a dynamic representation based on Saint-Venant equations and the real bathymetry of the reservoir. The comparison was based on breach of reservoir, maximum water level, flooded area, and wave arrival time in the valley downstream. The study showed that the greatest difference in attained water level was in the vicinity of the dam, and the difference decreased as the distance from the reservoir increased. The analysis showed that the static representation overestimated the maximum depth and inundated area by as much as 20 percent. This overestimation can be reduced by 30 to 40 percent by using dynamic representation. A dynamic model based on a synthetic trapezoidal reconstruction of the storage curve was used, given the lack of bathymetric data for the reservoir. It was concluded that this model can significantly reduce the uncertainty associated with the static model. 7 refs., 9 tabs., 7 figs.

  3. Smolt monitoring at the head of Lower Granite Reservoir and Lower Granite Dam, 1998.; ANNUAL

    International Nuclear Information System (INIS)

    2000-01-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka, during the 1998 spring outmigration at migrant traps on the Snake and Salmon rivers. All hatchery chinook salmon released above Lower Granite Dam 19 1998 were marked with a fin-clip. Total annual hatchery chinook salmon catch at the Snake River trap was 226% of the 1997 number and 110% of the 1996 catch. The wild chinook catch was 120% of the 1997 catch but was only 93% of 1996. Hatchery steelhead trout catch was 501% of 1997 numbers but only 90% of the 1996 numbers. Wild steelhead trout catch was 569% of 1997 and 125% of the 1996 numbers. The Snake River trap collected 106 age-0 chinook salmon. During 1998, for the first time, the Snake River trap captured a significant number of hatchery sockeye salmon (1,552) and hatchery coho salmon O. kisutch (166). Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations began on March 8 and were terminated for the season due to high flows on June 12. The trap was out of operation for 34 d during the season due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 476% and wild chinook salmon catch was 137% of 1997 numbers and 175% and 82% of 1996 catch, respectively. The hatchery steelhead trout collection in 1998 was 96% of the 1997 catch and 13% of the 1996 numbers. Wild steelhead trout collection in 1998 was 170% of the 1997 catch and 37% of the 1996 numbers. Travel time (d) and migration rate (km/d) through Lower Granite Reservoir for PIT-tagged chinook salmon and steelhead trout, marked at the head of the reservoir were affected by discharge. For fish tagged at the Snake River trap, statistical analysis of 1998 detected a significant relation between migration rate and discharge. For hatchery and

  4. Rapid reservoir erosion, hyperconcentrated flow, and downstream deposition triggered by breaching of 38 m tall Condit Dam, White Salmon River, Washington

    Science.gov (United States)

    Wilcox, Andrew C.; O'Connor, James E.; Major, Jon J.

    2014-01-01

    Condit Dam on the White Salmon River, Washington, a 38 m high dam impounding a large volume (1.8 million m3) of fine-grained sediment (60% sand, 35% silt and clay, and 5% gravel), was rapidly breached in October 2011. This unique dam decommissioning produced dramatic upstream and downstream geomorphic responses in the hours and weeks following breaching. Blasting a 5 m wide hole into the base of the dam resulted in rapid reservoir drawdown, abruptly releasing ~1.6 million m3 of reservoir water, exposing reservoir sediment to erosion, and triggering mass failures of the thickly accumulated reservoir sediment. Within 90 min of breaching, the reservoir's water and ~10% of its sediment had evacuated. At a gauging station 2.3 km downstream, flow increased briefly by 400 m3 s−1during passage of the initial pulse of released reservoir water, followed by a highly concentrated flow phase—up to 32% sediment by volume—as landslide-generated slurries from the reservoir moved downstream. This hyperconcentrated flow, analogous to those following volcanic eruptions or large landslides, draped the downstream river with predominantly fine sand. During the ensuing weeks, suspended-sediment concentration declined and sand and gravel bed load derived from continued reservoir erosion aggraded the channel by >1 m at the gauging station, after which the river incised back to near its initial elevation at this site. Within 15 weeks after breaching, over 1 million m3 of suspended load is estimated to have passed the gauging station, consistent with estimates that >60% of the reservoir's sediment had eroded. This dam removal highlights the influence of interactions among reservoir erosion processes, sediment composition, and style of decommissioning on rate of reservoir erosion and consequent downstream behavior of released sediment.

  5. [Effects of cascading hydropower dams operation on the structure and distribution pattern of benthic macroinvertebrate assemblages in Manwan Reservoir, Southwest China].

    Science.gov (United States)

    Li, Jin Peng; Dong, Shi Kui; Peng, Ming Chun; Wu, Xuan; Zhou, Fang; Yu, Yin

    2017-12-01

    Benthic macroinvertebrate assemblages are one of the biological groups in aquatic ecosystem most sensitive to the habitat change and degradation, and can be a biological indicator for the aquatic ecosystem change and succession in cascading hydropower dam reservoir. The middle and lower reaches of the Lancang River are key spot for international biodiversity conservation and ecological studies on the effects of cascading hydropower dam exploitation. In this study, the reservoir of Manwan hydropower dam, the first dam in Lancang-Mekong river main stream, was selected as the study site. The benthic macroinvertebrate assemblages were sampled in 2011 and 2016 respectively. Meanwhile, the survey data before impounding (natural river, 1996) and early stage of single dam (1997) were collected to conduct the overall analysis for structure, distribution pattern and evolution of benthic macroinvertebrate assemblages. The results showed that the dominant biological group was gradually changed from the Oligochaeta and Insecta to the Mollusca. Along the longitudinal gradient, the density and biomass of the benthic macroinvertebrate assemblages were remarkably increased in reservoir, especially in the lacustrine zone. As for the functional feeding group, the predator and gatherer-collector changed into filter-collector predominantly in lacustrine zone. With the cascading dams operation, the biotic index indicated that the water quality of reservoir in 2016 was better than in 2011. The evolution of benthic macroinvertebrate assemblages in the Manwan Reservoir was related to the operation of Xiaowan dam in the upper reach, the hydrological regime and siltation in the reservoir, and would continue with dynamic changes with the operation of the cascading hydropower dam.

  6. Impact of damming on the Chironomidae of the upper zone of a tropical run-of-the-river reservoir.

    Science.gov (United States)

    Brandimarte, A L; Anaya, M; Shimizu, G Y

    2016-06-01

    We examined the effects of the Mogi-Guaçu river damming (São Paulo State, Brazil) on the Chironomidae fauna. Pre, during, and post-filling sampling was carried out in the main channel and margins of one site in the upper zone of the reservoir, using a modified Petersen grab (325 cm2). We evaluated the total, subfamily, and tribe densities and also their relative abundance. Analysis of genera included densities, relative abundance, richness, and dominance. The Rosso's ecological value index (EVI) determined the ecological importance of each genus. There was a tendency of decrease of the total Chironomidae density, increase in the percentage of Chironomini, and decrease in densities and percentages of Orthocladiinae and Tanytarsini. These changes in percentage were respectively related to Polypedilum, Lopescladius, and Rheotanytarsus, the genera with the highest EVI values. After-filling richness was lower in the margins and dominance of genera did not change significantly. Chironomidae in the margins was more sensitive to damming than in the main channel. This difference in sensibility sustains the use of Chironomidae as bioindicators. Damming impact was indicated by the reduction of both genera richness in the margins and relative abundance of groups typical of faster waters. The results have highlighted the need for multi-habitat analysis combined with a before-after sampling approach in the environmental impact studies concerning the damming impact on the benthic fauna.

  7. Preliminary Three-Dimensional Simulation of Sediment and Cesium Transport in the Ogi Dam Reservoir using FLESCOT – Task 6, Subtask 2

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Kurikami, Hiroshi; Yokuda, Satoru T.

    2014-03-28

    After the accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, the Japan Atomic Energy Agency and the Pacific Northwest National Laboratory initiated a collaborative project on environmental restoration. In October 2013, the collaborative team started a task of three-dimensional modeling of sediment and cesium transport in the Fukushima environment using the FLESCOT (Flow, Energy, Salinity, Sediment Contaminant Transport) code. As the first trial, we applied it to the Ogi Dam Reservoir that is one of the reservoirs in the Japan Atomic Energy Agency’s (JAEA’s) investigation project. Three simulation cases under the following different temperature conditions were studied: • incoming rivers and the Ogi Dam Reservoir have the same water temperature • incoming rivers have lower water temperature than that of the reservoir • incoming rivers have higher water temperature than that of the reservoir. The preliminary simulations suggest that seasonal temperature changes influence the sediment and cesium transport. The preliminary results showed the following: • Suspended sand, and cesium adsorbed by sand, coming into the reservoirs from upstream rivers is deposited near the reservoir entrance. • Suspended silt, and cesium adsorbed by silt, is deposited farther in the reservoir. • Suspended clay, and cesium adsorbed by clay, travels the farthest into the reservoir. With sufficient time, the dissolved cesium reaches the downstream end of the reservoir. This preliminary modeling also suggests the possibility of a suitable dam operation to control the cesium migration farther downstream from the dam. JAEA has been sampling in the Ogi Dam Reservoir, but these data were not yet available for the current model calibration and validation for this reservoir. Nonetheless these preliminary FLESCOT modeling results were qualitatively valid and confirmed the applicability of the FLESCOT code to the Ogi Dam Reservoir, and in general to other reservoirs in

  8. Isotopic composition of nitrate and particulate organic matter in a pristine dam reservoir of western India: Implications for biogeochemical processes

    Digital Repository Service at National Institute of Oceanography (India)

    Bardhan, P.; Naqvi, S.W.A.; Karapurkar, S.G.; Shenoy, D.M.; Kurian, S.; Naik, H.

    , 767–779, 2017 www.biogeosciences.net/14/767/2017/ doi:10.5194/bg-14-767-2017 © Author(s) 2017. CC Attribution 3.0 License. Isotopic composition of nitrate and particulate organic matter in a pristine dam reservoir of western India: implications... basis. Samples for nitrate isotopic measurements were col- lected from 2011. The facility for nitrate isotope analysis was Biogeosciences, 14, 767–779, 2017 www.biogeosciences.net/14/767/2017/ P. Bardhan et al.: Isotopic composition of nitrate and POM...

  9. Predicting spread of invasive exotic plants into de-watered reservoirs following dam removal on the Elwha River, Olympic National Park, Washington

    Science.gov (United States)

    Woodward, Andrea; Torgersen, Christian E.; Chenoweth, Joshua; Beirne, Katherine; Acker, Steve

    2011-01-01

    The National Park Service is planning to start the restoration of the Elwha River ecosystem in Olympic National Park by removing two high head dams beginning in 2011. The potential for dispersal of exotic plants into dewatered reservoirs following dam removal, which would inhibit restoration of native vegetation, is of great concern. We focused on predicting long-distance dispersal of invasive exotic plants rather than diffusive spread because local sources of invasive species have been surveyed. We included the long-distance dispersal vectors: wind, water, birds, beavers, ungulates, and users of roads and trails. Using information about the current distribution of invasive species from two surveys, various geographic information system techniques and models, and statistical methods, we identified high-priority areas for Park staff to treat prior to dam removal, and areas of the dewatered reservoirs at risk after dam removal.

  10. Sedimentary record and anthropogenic pollution of a complex, multiple source fed dam reservoirs: An example from the Nové Mlýny reservoir, Czech Republic.

    Science.gov (United States)

    Sedláček, Jan; Bábek, Ondřej; Nováková, Tereza

    2017-01-01

    While numerous studies of dam reservoirs contamination are reported world-wide, we present a missing link in the study of reservoirs sourced from multiple river catchments. In such reservoirs, different point sources of contaminants and variable composition of their sedimentary matrices add to extremely complex geochemical patterns. We studied a unique, step-wise filled Nové Mlýny dam reservoir, Czech Republic, which consists of three interconnected sub-basins. Their source areas are located in units with contrasting geology and different levels and sources of contamination. The aim of this study is to provide an insight into the provenance of the sediment, including lithogenic elements and anthropogenic pollutants, to investigate the sediment dispersal across the reservoir, and to assess the heavy metal pollution in each basin. The study is based on multi-proxy stratigraphic analysis and geochemistry of sediment cores. There is a considerable gradient in the sediment grain size, brightness, MS and geochemistry, which reflects changing hydrodynamic energy conditions and primary pelagic production of CaCO 3 . The thickness of sediments generally decreases from proximal to distal parts, but underwater currents can accumulate higher amounts of sediments in distal parts near the thalweg line. Average sedimentation rates vary over a wide range from 0.58cm/yr to 2.33cm/yr. In addition, the petrophysical patterns, concentrations of lithogenic elements and their ratios made it possible to identify two main provenance areas, the Dyje River catchment (upper basin) and the Svratka and Jihlava River catchments (middle and lower basin). Enrichment factors (EF) were used for distinguishing the anthropogenic element contribution from the local background levels. We found moderate Zn and Cu pollution (EF ~2 to 5) in the upper basin and Zn, Cu and Pb (EF ~2 to 4.5) in the middle basin with the peak contamination in the late 1980s, indicating that the two basins have different

  11. Dynamic Response of Dam-Reservoir Systems: Review and a Semi-Analytical Proposal

    Directory of Open Access Journals (Sweden)

    Paulo Marcelo Vieira Ribeiro

    Full Text Available Abstract This paper presents a review of current techniques employed for dynamic analysis of concrete gravity dams under seismic action. Traditional procedures applied in design bureaus, such as the Pseudo-Static method, often neglect structural dynamic properties, as well as ground amplification effects. A practical alternative arises with the Pseudo-Dynamic method, which considers a simplified spectrum response in the fundamental mode. The authors propose a self-contained development and detailed examples of this latter method, including a comparison with finite element models using transient response of fluid-structure systems. It is verified that application of the traditional procedure should be done carefully and limited to extremely rigid dams. On the other hand, the proposed development is straightforward and in agreement with finite element results for general cases where dam flexibility plays an important role.

  12. Dynamics of fluctuations of Cs-137 contents in the bottom sediment in limnetic dam reservoir Goczalkowice

    International Nuclear Information System (INIS)

    Kwapulinski, J.; Majchrzyk, H.; Kalita, T.; Miroslawski, J.

    1986-01-01

    The results of 137 Cs studies in bottom sediment in the Goczalkowice reservoir are presented. The determined coefficients of aquatic migration, difusion in bottom sediment and water in vertical section confirm zonal nature of 137 Cs occurrance and accumulation in the reservoir. 5 refs., 1 fig., 6 tabs. (author)

  13. Assessment of Short Term Flood Operation Strategies Using Numerical Weather Prediction Data in YUVACΙK DAM Reservoir, Turkey

    Science.gov (United States)

    Uysal, G.; Yavuz, O.; Sensoy, A.; Sorman, A.; Akgun, T.; Gezgin, T.

    2011-12-01

    Yuvacik Dam Reservoir Basin, located in the Marmara region of Turkey with 248 km2 drainage area, has steep topography, mild and rainy climate thus induces high flood potential with fast flow response, especially to early spring and fall precipitation events. Moreover, the basin provides considerable snowmelt contribution to the streamflow during melt season since the elevation ranges between 80 - 1548 m. The long term strategies are based on supplying annual demand of 142 hm3 water despite a relatively small reservoir capacity of 51 hm3. This situation makes short term release decisions as the challenging task regarding the constrained downstream safe channel capacity especially in times of floods. Providing the demand of 1.5 million populated city of Kocaeli is the highest priority issue in terms of reservoir management but risk optimization is also required due to flood regulation. Although, the spillway capacity is 1560 m3/s, the maximum amount of water to be released is set as 100 m3/s by the regional water authority taking into consideration the downstream channel capacity which passes through industrial region of the city. The reservoir is a controlled one and it is possible to hold back the 15 hm3 additional water by keeping the gates closed. Flood regulation is set to achieve the maximum possible flood attenuation by using the full flood-control zone capacity in the reservoir before making releases in excess of the downstream safe-channel capacity. However, the operators still need to exceed flood regulation zones to take precautions for drought summer periods in order to supply water without any shortage that increases the risk in times of flood. Regarding to this circumstances, a hydrological model integrated reservoir modeling system, is applied to account for the physical behavior of the system. Hence, this reservoir modeling is carried out to analyze both previous decisions and also the future scenarios as a decision support tool for operators. In the

  14. Dams: impacts on the species diversity; Impacts des reservoirs sur la biodiversite

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Domingos de [Quebec Univ., Montreal, PQ (Canada). Dept. de Sciences Biologiques, Inst. de Sciences de l`Environnement

    1996-12-31

    Always you change one ecosystem, you have impacts on the species diversity. The work try to show some impacts of dams for hydroelectric power generation. First of all the author analyses the impacts on the habitats and ecosystems. He considers the problems on a variety of species, since plants and animals that living on the border of the river until the fishes, birds, invertebrates and the mammals. The example of 3 dams, La Grande, Opinaca and Caniapiseau, on Quebec, Canada, are used to give support to the work 14 refs., 1 tab.

  15. The morphodynamics of sediment movement through a reservoir during dam removal

    OpenAIRE

    Bromley, Chris

    2008-01-01

    Dam removal has recently emerged as a growing trend in river rehabilitation in the United States. The rate of dam removal has been increasing rapidly since 2000, but is doing so with large gaps in our understanding of how the fluvial system will respond to this disturbance. Most of the structures removed to date have been relatively small and, in the vast majority of cases, have not received any pre- or post-removal monitoring. Very few large structures have been removed but, when such remova...

  16. PREDICTION OF RESERVOIR FLOW RATE OF DEZ DAM BY THE PROBABILITY MATRIX METHOD

    Directory of Open Access Journals (Sweden)

    Mohammad Hashem Kanani

    2012-12-01

    Full Text Available The data collected from the operation of existing storage reservoirs, could offer valuable information for the better allocation and management of fresh water rates for future use to mitigation droughts effect. In this paper the long-term Dez reservoir (IRAN water rate prediction is presented using probability matrix method. Data is analyzed to find the probability matrix of water rates in Dez reservoir based on the previous history of annual water entrance during the past and present years(40 years. The algorithm developed covers both, the overflow and non-overflow conditions in the reservoir. Result of this study shows that in non-overflow conditions the most exigency case is equal to 75%. This means that, if the reservoir is empty (the stored water is less than 100 MCM this year, it would be also empty by 75% next year. The stored water in the reservoir would be less than 300 MCM by 85% next year if the reservoir is empty this year. This percentage decreases to 70% next year if the water of reservoir is less than 300 MCM this year. The percentage also decreases to 5% next year if the reservoir is full this year. In overflow conditions the most exigency case is equal to 75% again. The reservoir volume would be less than 150 MCM by 90% next year, if it is empty this year. This percentage decreases to 70% if its water volume is less than 300 MCM and 55% if the water volume is less than 500 MCM this year. Result shows that too, if the probability matrix of water rates to a reservoir is multiplied by itself repeatedly; it converges to a constant probability matrix, which could be used to predict the long-term water rate of the reservoir. In other words, the probability matrix of series of water rates is changed to a steady probability matrix in the course of time, which could reflect the hydrological behavior of the watershed and could be easily used for the long-term prediction of water storage in the down stream reservoirs.

  17. Long-Term Changes in Sediment and Nutrient Delivery from Conowingo Dam to Chesapeake Bay: Effects of Reservoir Sedimentation.

    Science.gov (United States)

    Zhang, Qian; Hirsch, Robert M; Ball, William P

    2016-02-16

    Reduction of suspended sediment (SS), total phosphorus (TP), and total nitrogen is an important focus for Chesapeake Bay watershed management. The Susquehanna River, the bay's largest tributary, has drawn attention because SS loads from behind Conowingo Dam (near the river's mouth) have been rising dramatically. To better understand these changes, we evaluated histories of concentration and loading (1986-2013) using data from sites above and below Conowingo Reservoir. First, observed concentration-discharge relationships show that SS and TP concentrations at the reservoir inlet have declined under most discharges in recent decades, but without corresponding declines at the outlet, implying recently diminished reservoir trapping. Second, best estimates of mass balance suggest decreasing net deposition of SS and TP in recent decades over a wide range of discharges, with cumulative mass generally dominated by the 75∼99.5th percentile of daily Conowingo discharges. Finally, stationary models that better accommodate effects of riverflow variability also support the conclusion of diminished trapping of SS and TP under a range of discharges that includes those well below the literature-reported scour threshold. Overall, these findings suggest that decreased net deposition of SS and TP has occurred at subscour levels of discharge, which has significant implications for the Chesapeake Bay ecosystem.

  18. Effect of a dam on the optical properties of different-sized fractions of dissolved organic matter in a mid-subtropical drinking water source reservoir.

    Science.gov (United States)

    Sun, Qiyuan; Jiang, Juan; Zheng, Yuyi; Wang, Feifeng; Wu, Chunshan; Xie, Rong-Rong

    2017-11-15

    The presence of a dam on a river is believed to have a key role in affecting changes in the components of the chromophoric dissolved organic matter (CDOM) in reservoirs. However, questions remain about the mechanisms that control these changes. In this study, we used tangential ultrafiltration, fluorescence spectrum and phytoplankton cell density detection to explore the impacts of a dam on the CDOM components in the Shanzai Reservoir, a source of drinking water. The results demonstrated each CDOM size fraction comprised two main components, namely C1 (protein-like substance) and C2 (humic-like substance). The C1 content had a higher value in areas with slow flow than in the normal river channel, while the C2 contents were generally stable in the flow direction. The topography of the reservoir site affected the structure of the CDOM components based on changes in the hydraulic conditions caused by the dam. The variations in the CDOM components, hydraulic parameters and fluorescence indices in the river flow direction indicated that the contribution of the phytoplankton to the CDOM content increased as the distance to the dam decreased, phytoplankton metabolism enhanced C1 content of the 1-10kDa molecular weights range fraction. Further, the contributions of different phytoplankton biomass to C1 proved that the dam changed the hydraulic conditions, had secondary effects on the metabolism of the phytoplankton, and resulted in changes in the structure of the CDOM components. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Phytoplankton of the Boguchany reservoir in 2016-2017 at the stations in front of the hydroelectric dam

    Directory of Open Access Journals (Sweden)

    M. V. Usoltseva

    2017-12-01

    Full Text Available The species structure and seasonal dynamics of the phytoplankton of the dam area of the Boguchany Reservoir were studied in the first years of operation of the hydroelectric power station in 2016-2017. Two peaks of algal bloom are noted in spring and summer. Mass species were: diatom Stephanodiscus minutulus and dinophyte Gymnodinium baicalense in spring; diatoms Asterionella formosa and Fragilaria crotonensis, blue-green Dolichospermum lemmermannii, D. flosaquae, D. flosaquae f. spiroides and Aphanizomenon flosaquae; green Sphaerocystis planctonica and dinophyte Ceratium hirundinella in summer; diatoms F. crotonensis and A. formosa, cryptophytic Rhodomonas pusilla and Cryptomonas ovata in autumn. The cryptophyte R. pusilla and the Cryptomonas species were dominated under the ice. The maximum number of phytoplankton (9 million cells in liter was recorded in the spring. According to the indixes of saprobity, the purity of water corresponded to II-III quality classes (pure and moderately polluted water.

  20. Abiquiu Dam and Reservoir, Rio Grande Basin, Rio Chama, New Mexico. Embankment Criteria and Performance Report.

    Science.gov (United States)

    1987-04-01

    EMBANKMENT CRITERIA AND PERFORMANCE REPORT PERTINENT DATA 1. General Data. LOCATION: Rio Arriba County, New Mexico, on the Rio Chama at river mile 33. PURPOSE...is located across the Rio Chama, approximately 30 miles upstream from its confluence with the Rio Grande, in Rio Arriba County, New Mexico. The dam is...6600- 4 i ’. 6600 65060- -60 6600- a + v6500s-go FA**v~w -6500 6300- 60 - ~ ~ ~ wo Ala filll------------------ EMBNKEN SECTION62 *LDN WOR SAFEL VAIE

  1. Revegetation of the riparian zone of the Three Gorges Dam Reservoir leads to increased soil bacterial diversity.

    Science.gov (United States)

    Ren, Qingshui; Li, Changxiao; Yang, Wenhang; Song, Hong; Ma, Peng; Wang, Chaoying; Schneider, Rebecca L; Morreale, Stephen J

    2018-06-06

    As one of the most active components in soil, bacteria can affect soil physicochemical properties, its biological characteristics, and even its quality and health. We characterized dynamics of the soil bacterial diversity in planted (with Taxodium distichum) and unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR), in southwestern China, in order to accurately quantify the changes in long-term soil bacterial community structure after revegetation. Measurements were taken annually in situ in the TGDR over the course of 5 years, from 2012 to 2016. Soil chemical properties and bacterial diversity were analyzed in both the planted and unplanted soil. After revegetation, the soil chemical properties in planted soil were significantly different than in unplanted soil. The effects of treatment, time, and the interaction of both time and treatment had significant impacts on most diversity indices. Specifically, the bacterial community diversity indices in planted soil were significantly higher and more stable than that in unplanted soil. The correlation analyses indicated that the diversity indices correlated with the pH value, organic matter, and soil available nutrients. After revegetation in the riparian zone of the TGDR, the soil quality and health is closely related to the observed bacterial diversity, and a higher bacterial diversity avails the maintenance of soil functionality. Thus, more reforestation should be carried out in the riparian zone of the TGDR, so as to effectively mitigate the negative ecological impacts of the dam. Vegetating the reservoir banks with Taxodium distichum proved successful, but planting mixed stands of native tree species could promote even higher riparian soil biodiversity and improved levels of ecosystem functioning within the TGDR.

  2. Forecasting analysis of runoff for reservoir regulation of dams and weirs in terms of hydro power plant operation

    International Nuclear Information System (INIS)

    Maradjieva, Mariana; Nikolov, Nikola

    2008-01-01

    In order to meet the needs of Hydropower Plant (HPP) production new algorithms and software were developed for daily, seasonal, annual and long-term control of the runoff for the design of dam and weirs. This control is carried out for monitored periods from 20 to 50 years. The control depends on economic considerations, namely that the accepted probability of required water power is 90%, i.e. concerning the runoff and in this way for the useful volume of water dams. The research is accomplished by a design with the observations. First the hydrometric stations are selected at the available analogy with the building project and then the correlative connection is found assessed by general and true correlative coefficients. The transferring to the project of the observations for the average annual and average monthly water discharges is made with the coefficient of the analogy. The theoretical probability curves are chosen with a minimum dispersion. By the last curves the average monthly distributions are settled with probability from 2% to 90% by statistical method. During the investigated period of the regulation the volumes of discharge, overflow and shortage are calculated as and the determination for the accepted volume of the reservoir if the normative probability of the need is executed. As well the power output of the HPP and its participation in the coverage of the charge diagram on the peak load, under peak load, daily and nightly part are determined in separate observed or forecasting periods. The upper problems about the design and the operation of HPP, water output, reservoir volume and coverage of the charge diagram are solved by iterations. Practical examples are given for the runoff and for the time forecasting system.

  3. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Brimmer, Arnold F.

    1994-10-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss smolts during the 1994 spring outmigration at migrant traps on the Snake River, Clearwater River, and Salmon River. The 1994 snowpack was among the lowest since the beginning of the present drought, and the subsequent runoff was very poor. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1994. Total annual (hatchery + wild) chinook salmon catch at the Snake River trap was 1.5 times greater than in 1993. Hatchery and wild steelhead trout catches were similar to 1993. The Snake River trap collected 30 age 0 chinook salmon. Hatchery chinook salmon catch at the Clearwater River trap was 3.5 times higher than in 1993, and wild chinook salmon catch was 4.2 times higher. Hatchery steelhead trout trap catch was less than half of 1993 numbers because the trap was fishing near the north shore during the majority of the hatchery steelhead movement due to flow augmentations from Dworshak. Wild steelhead trout trap catch was 2 times higher than in 1993. The Salmon River trap was operated for about a month longer in 1994 than in 1993 due to extremely low flows. Hatchery chinook salmon catch was 1.4 times greater in 1994 than the previous year. Wild chinook salmon catch was slightly less in 1994. The 1994 hatchery steelhead trout collection did not change significantly from 1993 numbers. Wild steelhead trout collection in 1994 was 59% of the 1993 catch. Fish tagged with Passive Integrated Transponder (PIT) tags at the Snake River trap were interrogated at four dams with PIT tag detection systems (Lower Granite, Little Goose, Lower Monumental, and McNary dams). Because of the addition of the fourth interrogation site (Lower Monumental) in 1993, cumulative interrogation data is not comparable with the prior five years (1988-1992).

  4. Considerations in Managing the Fill Rate of the Grand Ethiopian Renaissance Dam Reservoir Using a System Dynamics Approach.

    Science.gov (United States)

    Keith, Bruce; Ford, David N.; Horton, Radley M.

    2016-01-01

    The purpose of this study is to evaluate simulated fill rate scenarios for the Grand Ethiopian Renaissance Dam while taking into account plausible climate change outcomes for the Nile River Basin. The region lacks a comprehensive equitable water resource management strategy, which creates regional security concerns and future possible conflicts. We employ climate estimates from 33 general circulation models within a system dynamics model as a step in moving toward a feasible regional water resource management strategy. We find that annual reservoir fill rates of 8-15% are capable of building hydroelectric capacity in Ethiopia while concurrently ensuring a minimum level of stream flow disruption into Egypt before 2039. Insofar as climate change estimates suggest a modest average increase in stream flow into the Aswan, climate changes through 2039 are unlikely to affect the fill rate policies. However, larger fill rates will have a more detrimental effect on stream flow into the Aswan, particularly beyond a policy of 15%. While this study demonstrates that a technical solution for reservoir fill rates is feasible, the corresponding policy challenge is political. Implementation of water resource management strategies in the Nile River Basin specifically and Africa generally will necessitate a national and regional willingness to cooperate.

  5. New approaches to screening infrastructure investments in multi-reservoir systems- Evaluating proposed dams in Ethiopia and Kenya

    Science.gov (United States)

    Harou, J. J.; Geressu, R. T.; Hurford, A. P.

    2014-12-01

    Two approaches have been used traditionally to screen infrastructure investments in multi-reservoir systems: scenario analysis of a few simulated designs and deterministic optimization, sometimes using hydro-economic models or screening optimization models. Simulation models realistically represent proposed water systems and can easily include multiple performance metrics; however each prospective system operating rules need to be formulated and simulated for each proposed design (time consuming. Optimization models have been used to overcome this burden. Screening optimization models use integer or non-linear programming and can be challenging to apply to large and/or multi-objective systems. Hydro-economic models that use deterministic (implicit stochastic) optimization must be modified to examine each different plan and they cannot always reproduce realistic or politically acceptable system operations. In this presentation we demonstrate the application of a new screening approach to multi-reservoir systems where operating rules and new assets (dams) are simultaneously optimized in a multi-criteria context. Results are not least cost investment plans that satisfy reliability or other engineering constraints, but rather Pareto-optimal sets of asset portfolios that work well under historical and/or future scenarios. This is achieved by using stakeholder-built simulation models linked to multi-criteria search algorithms (e.g. many objective evolutionary algorithms, MOEA). Typical output is demonstrated through two case-studies on the Tana and Blue Nile rivers where operating rules and reservoir assets are efficiently screened together considering stakeholder-defined metrics. The focus on the Tana system is how reservoir operating rules and new irrigation schemes should be co-managed to limit ecological damages. On the Nile system, we identify Blue Nile river reservoir capacities that least negatively impact downstream Nile nations. Limitations and new directions of

  6. Archaeological Reconnaissance in the 50 Year Flood Easement Lands. Harry S. Truman Dam and Reservoir, Missouri

    Science.gov (United States)

    1983-01-01

    No. 14. Knoxville. Chomko, Stephen A. 1978 Phillips Spring, 23111216: A Multicomponent Site in the Western Missouri Ozarkq. Plains Anthropologist 23...Office of the State Archaeologist, Iniversity of Iowa Report 11. Iowa City. Pp. 163-166. Henry, Donald 0., Barbara Butler and Stephen A. Hall 1979 The...North America. M- Graw -Hill. New York. 1 ~168 .Iohnson, Alfred E. 1968 Archaeological Investigations in the Clinton Reservoir Area, Eastern Kansas

  7. Simulation of Sediment and Cesium Transport in the Ukedo River and the Ogi Dam Reservoir during a Rainfall Event using the TODAM Code

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Yokuda, Satoru T.; Kurikami, Hiroshi

    2014-03-28

    The accident at the Fukushima Daiichi Nuclear Power Plant in March 2011 caused widespread environmental contamination. Although decontamination activities have been performed in residential areas of the Fukushima area, decontamination of forests, rivers, and reservoirs is still controversial because of the economical, ecological, and technical difficulties. Thus, an evaluation of contaminant transport in such an environment is important for safety assessment and for implementation of possible countermeasures to reduce radiation exposure to the public. The investigation revealed that heavy rainfall events play a significant role in transporting radioactive cesium deposited on the land surface, via soil erosion and sediment transport in rivers. Therefore, we simulated the sediment and cesium transport in the Ukedo River and its tributaries in Fukushima Prefecture, including the Ogaki Dam Reservoir, and the Ogi Dam Reservoir of the Oginosawa River in Fukushima Prefecture during and after a heavy rainfall event by using the TODAM (Time-dependent, One-dimensional Degradation And Migration) code. The main outcomes are the following: • Suspended sand is mostly deposited on the river bottom. Suspended silt and clay, on the other hand, are hardly deposited in the Ukedo River and its tributaries except in the Ogaki Dam Reservoir in the Ukedo River even in low river discharge conditions. • Cesium migrates mainly during high river discharge periods during heavy rainfall events. Silt and clay play more important roles in cesium transport to the sea than sand does. • The simulation results explain variations in the field data on cesium distributions in the river. Additional field data currently being collected and further modeling with these data may shed more light on the cesium distribution variations. • Effects of 40-hour heavy rainfall events on clay and cesium transport continue for more than a month. This is because these reservoirs slow down the storm-induced high

  8. Post flooding damage assessment of earth dams and historical reservoirs using non-invasive geophysical techniques

    Science.gov (United States)

    Sentenac, Philippe; Benes, Vojtech; Budinsky, Vladimir; Keenan, Helen; Baron, Ron

    2017-11-01

    This paper describes the use of four geophysical techniques to map the structural integrity of historical earth reservoir embankments which are susceptible to natural decay with time. The four techniques that were used to assess the post flood damage were 1. A fast scanning technique using a dipole electromagnetic profile apparatus (GEM2), 2. Electrical Resistivity Tomography (ERT) in order to obtain a high resolution image of the shape of the damaged/seepage zone, 3. Self-Potential surveys were carried out to relate the detected seepage evolution and change of the water displacement inside the embankment, 4. The washed zone in the areas with piping was characterised with microgravimetry. The four geophysical techniques used were evaluated against the case studies of two reservoirs in South Bohemia, Czech Republic. A risk approach based on the Geophysical results was undertaken for the reservoir embankments. The four techniques together enabled a comprehensive non-invasive assessment whereby remedial action could be recommended where required. Conclusions were also drawn on the efficiency of the techniques to be applied for embankments with wood structures.

  9. Movements of adult Atlantic salmon through a reservoir above a hydroelectric dam: Loch Faskally

    International Nuclear Information System (INIS)

    Gowans, A.R.D.; Priede, I.G.

    1999-01-01

    Movements of adult Atlantic salmon were determined as they migrated through Loch Faskally, a 4-km long hydroelectric reservoir in North-east Scotland. The horizontal and vertical movements of four salmon were monitored for periods of 4-7 days using depth-sensing acoustic transmitters in June-July 1995. Each fish began sustained directed upstream movements within 5.5 h after release at swimming speeds of 0.15-0.40 bl s -1 . Three fish reached the head of the loch after 7.25-17 h, but then returned downstream. The four fish remained in the upper half of the loch for 15-51 days, making localized movements. Mean depths of fish were 3.7-4.0 m (max 20.7 m). Two fish were recorded at significantly shallower depths at night during the day. Departure from the loch coincided with periods of high water flow into the reservoir. In May-July 1996, 17 radio-tagged salmon entered Loch Faskally and reached the head of the loch in 3 h-5.8 days (mean 39 h). The durations of stay in the loch varied from 3 h 50 min to 67.4 days (mean 10.9 days). Only two radio-tagged salmon left the loch under conditions of high water flow into the loch. (author)

  10. Designing multi-reservoir system designs via efficient water-energy-food nexus trade-offs - Selecting new hydropower dams for the Blue Nile and Nepal's Koshi Basin

    Science.gov (United States)

    Harou, J. J.; Hurford, A.; Geressu, R. T.

    2015-12-01

    Many of the world's multi-reservoir water resource systems are being considered for further development of hydropower and irrigation aiming to meet economic, political and ecological goals. Complex river basins serve many needs so how should the different proposed groupings of reservoirs and their operations be evaluated? How should uncertainty about future supply and demand conditions be factored in? What reservoir designs can meet multiple goals and perform robustly in a context of global change? We propose an optimized multi-criteria screening approach to identify best performing designs, i.e., the selection, size and operating rules of new reservoirs within multi-reservoir systems in a context of deeply uncertain change. Reservoir release operating rules and storage sizes are optimized concurrently for each separate infrastructure design under consideration across many scenarios representing plausible future conditions. Outputs reveal system trade-offs using multi-dimensional scatter plots where each point represents an approximately Pareto-optimal design. The method is applied to proposed Blue Nile River reservoirs in Ethiopia, where trade-offs between capital costs, total and firm energy output, aggregate storage and downstream irrigation and energy provision for the best performing designs are evaluated. The impact of filling period for large reservoirs is considered in a context of hydrological uncertainty. The approach is also applied to the Koshi basin in Nepal where combinations of hydropower storage and run-of-river dams are being considered for investment. We show searching for investment portfolios that meet multiple objectives provides stakeholders with a rich view on the trade-offs inherent in the nexus and how different investment bundles perform differently under plausible futures. Both case-studies show how the proposed approach helps explore and understand the implications of investing in new dams in a global change context.

  11. Laboratory tests of bentonite stabilization of bottom sediments from a dam reservoir in relation to their usage in municipal solid waste landfill liners

    Directory of Open Access Journals (Sweden)

    Karolina Koś

    2016-09-01

    Full Text Available Geotechnical parameters of bottom sediments from a dam reservoir (Rzeszowski Reservoir, Poland with bentonite addition are presented in the paper. Tests were carried out in the aspect of the possible usage of sediments as a material for soil liners in Municipal Solid Waste Landfill. Mentioned sediments did not fulfilled the permeability and plasticity criteria defined for soils that can be used in liners. The bentonite addition caused, among other things, a decrease in permeability coefficient and increase in plasticity index. Based on the carried out tests it was stated that sediments with 6% addition of bentonite fulfil all requirements and can be used for liners in MSWL.

  12. Technical Note: Stability of a Levee Made of Bottom Sediments From a Dam Reservoir

    Directory of Open Access Journals (Sweden)

    Koś Karolina

    2015-02-01

    Full Text Available Stability analysis of a levee made of the bottom sediments from Czorsztyn-Niedzica Reservoir is presented in the paper. These sediments were classified as silty sands and, based on the authors' own research, their geotechnical parameters were beneficial, so the possibility of using this material for the hydraulic embankments was considered. Stability and filtration calculations were carried out for a levee that had the same top width - 3 m, slope inclinations 1:2 and different heights: 4, 6 and 8 m. Two methods were used: analytical and numerical. Calculations were carried out without and with a steady and unsteady seepage filtration. Based on the analysis carried out it was stated that the levee made of the bottom sediments is stable even at the height of 8.0 m, although because of the seepage on the downstream side it is recommended to use a drainage at the toe of the slope.

  13. Circulation of copper in the biotic compartments of a freshwater dammed reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Vinot, I.; Pihan, J.C

    2005-01-01

    This study concerns a chronic copper release in an aquatic ecosystem: Mirgenbach reservoir; which is characterized by high salinity, conductivity and hardness, a eutrophic state and a high temperature. To study the bioavailability of copper in the biotic compartments, the sampling covered the entire food chain (phyto- and zooplankton, macroalgae, aquatic plants, crustaceans, mollusks, and fish). Of the organisms present, the filter feeder Dreissena polymorpha, the detritivorous Bithynia tentaculata and Orconectes limosus were most contaminated by copper. The level of copper found in fish was the lowest. Body copper concentrations recorded in the present study show large variability between species even in some that are closely related. In most cases, however, the metal handling strategy, feeding habits, morphology and ecology can, at least partially, explain the metal content recorded. Pollution factors have been used to assess the state of contamination of the food chain. This study showed finally that the copper in the lake is bioavailable and bioaccumulated by organisms up to high levels and some effects of long-term toxicity of copper on benthic community and planktonic biomass were pointed out.

  14. Circulation of copper in the biotic compartments of a freshwater dammed reservoir

    International Nuclear Information System (INIS)

    Vinot, I.; Pihan, J.C.

    2005-01-01

    This study concerns a chronic copper release in an aquatic ecosystem: Mirgenbach reservoir; which is characterized by high salinity, conductivity and hardness, a eutrophic state and a high temperature. To study the bioavailability of copper in the biotic compartments, the sampling covered the entire food chain (phyto- and zooplankton, macroalgae, aquatic plants, crustaceans, mollusks, and fish). Of the organisms present, the filter feeder Dreissena polymorpha, the detritivorous Bithynia tentaculata and Orconectes limosus were most contaminated by copper. The level of copper found in fish was the lowest. Body copper concentrations recorded in the present study show large variability between species even in some that are closely related. In most cases, however, the metal handling strategy, feeding habits, morphology and ecology can, at least partially, explain the metal content recorded. Pollution factors have been used to assess the state of contamination of the food chain. This study showed finally that the copper in the lake is bioavailable and bioaccumulated by organisms up to high levels and some effects of long-term toxicity of copper on benthic community and planktonic biomass were pointed out

  15. Circulation of copper in the biotic compartments of a freshwater dammed reservoir.

    Science.gov (United States)

    Vinot, I; Pihan, J C

    2005-01-01

    This study concerns a chronic copper release in an aquatic ecosystem: Mirgenbach reservoir; which is characterized by high salinity, conductivity and hardness, a eutrophic state and a high temperature. To study the bioavailability of copper in the biotic compartments, the sampling covered the entire food chain (phyto- and zooplankton, macroalgae, aquatic plants, crustaceans, mollusks, and fish). Of the organisms present, the filter feeder Dreissena polymorpha, the detritivorous Bithynia tentaculata and Orconectes limosus were most contaminated by copper. The level of copper found in fish was the lowest. Body copper concentrations recorded in the present study show large variability between species even in some that are closely related. In most cases, however, the metal handling strategy, feeding habits, morphology and ecology can, at least partially, explain the metal content recorded. Pollution factors have been used to assess the state of contamination of the food chain. This study showed finally that the copper in the lake is bioavailable and bioaccumulated by organisms up to high levels and some effects of long-term toxicity of copper on benthic community and planktonic biomass were pointed out.

  16. Sedimentological and Geomorphological Effects of Reservoir Flushing: The Cachi Reservoir, Costa Rica, 1996

    DEFF Research Database (Denmark)

    Brandt, Anders; Swenning, Joar

    1999-01-01

    Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs......Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs...

  17. PAH distribution and mass fluxes in the Three Gorges Reservoir after impoundment of the Three Gorges Dam.

    Science.gov (United States)

    Deyerling, Dominik; Wang, Jingxian; Hu, Wei; Westrich, Bernhard; Peng, Chengrong; Bi, Yonghong; Henkelmann, Bernhard; Schramm, Karl-Werner

    2014-09-01

    Mass fluxes of polycyclic aromatic hydrocarbons (PAHs) were calculated for the Three Gorges Reservoir (TGR) in China, based on concentration and discharge data from the Yangtze River. Virtual Organisms (VOs) have been applied during four campaigns in 2008, 2009 (twice) and 2011 at sampling sites distributed from Chongqing to Maoping. The total PAH mass fluxes ranged from 110 to 2,160 mg s(-1). Highest loads were determined at Chongqing with a decreasing trend towards Maoping in all four sampling campaigns. PAH remediation capacity of the TGR was found to be high as the mass flux reduced by more than half from upstream to downstream. Responsible processes are thought to be adsorption of PAH to suspended particles, dilution and degradation. Furthermore, the dependence of PAH concentration upon water depth was investigated at Maoping in front of the Three Gorges Dam. Although considerable differences could be revealed, there was no trend observable. Sampling of water with self-packed filter cartridges confirmed more homogenous PAH depth distribution. Moreover, PAH content of suspended particles was estimated from water concentrations gathered by VOs based on a water-particle separation model and subsequently compared to PAH concentration measured in water and in filter cartridges. It could be shown that the modeled data predicts the concentration caused by particle-bound PAHs to be about 6 times lower than PAHs dissolved in water. Besides, the model estimates the proportions of 5- and 6-ring PAHs being higher than in water phase. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Longitudinal variability of phosphorus fractions in sediments of a canyon reservoir due to cascade dam construction: a case study in Lancang River, China.

    Directory of Open Access Journals (Sweden)

    Qi Liu

    Full Text Available Dam construction causes the accumulation of phosphorus in the sediments of reservoirs and increases the release rate of internal phosphorus (P loading. This study investigated the longitudinal variability of phosphorus fractions in sediments and the relationship between the contents of phosphorus fractions and its influencing factors of the Manwan Reservoir, Lancang River, Yunnan Province, China. Five sedimentary phosphorus fractions were quantified separately: loosely bound P (ex-P; reductant soluble P (BD-P; metal oxide-bound P (NaOH-P; calcium-bound P (HCl-P, and residual-P. The results showed that the total phosphorus contents ranged from 623 to 899 µg/g and were correlated positively with iron content in the sediments of the reservoir. The rank order of P fractions in sediments of the mainstream was HCl-P>NaOH-P>residual-P>BD-P>ex-P, while it was residual-P>HCl-P>NaOH-P>BD-P>ex-P in those of the tributaries. The contents of bio-available phosphorus in the tributaries, including ex-P, BD-P and NaOH-P, were significantly lower than those in the mainstream. The contents of ex-P, BD-P, NaOH-P showed a similar increasing trend from the tail to the head of the Manwan Reservoir, which contributed to the relatively higher content of bio-available phosphorus, and represents a high bio-available phosphorus releasing risk within a distance of 10 km from Manwan Dam. Correlation and redundancy analyses showed that distance to Manwan Dam and the silt/clay fraction of sediments were related closely to the spatial variation of bio-available phosphorus.

  19. Trends and evolution of contamination in a well-dated water reservoir sedimentary archive: the Brno Dam, Moravia, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Sedláček, J.; Bábek, O.; Matys Grygar, Tomáš

    2013-01-01

    Roč. 69, č. 8 (2013), s. 2581-2593 ISSN 1866-6280 Institutional support: RVO:61388980 Keywords : Brno Dam * Dam sediments * Cs-137 dating * Heavy metals * Eutrophication Subject RIV: DD - Geochemistry Impact factor: 1.572, year: 2013

  20. People and dams: environmental and socio-economic changes induced by a reservoir in Fincha'a watershed, western Ethiopia

    NARCIS (Netherlands)

    Bezuayehu, T.O.

    2006-01-01

    Dams that store water for electricity, irrigation, domestic water supply or flood control have been constructed for thousands of years worldwide. In too many cases, an unacceptable and often unnecessary price has been paid by watershed inhabitants to secure dam benefits, especially in social and

  1. National Program for Inspection of Non-Federal Dams. Babson Reservoir Dam (MA 00187), Massachusetts-Rhode Island Coastal Basin, Gloucester, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1978-11-01

    DIVISION, CORPS OF ENGINEERSWALTHAM, MASS 02154 NTIS GRA&n F NOVEMBER 1978 DTIC TAB Ŕ Justiftcati n r r D stributijon/ Availabilit -" os Dist jSpecial...flashboards removed and can pass the PMF outflow of 1530 cfs (750 csm) with the water level 0.6 ft.Ui below the top of the concrete core wall. Within... water treatment plant and responsible for the day-to-day operation of the dam. He represented the owner during this investigation. His address and

  2. Sedimentary record and anthropogenic pollution of a complex, multiple source fed dam reservoirs: An example from the Nove Mlyny reservoir, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Sedláček, J.; Bábek, O.; Nováková, Tereza

    2017-01-01

    Roč. 574, JAN (2017), s. 1456-1471 ISSN 0048-9697 Institutional support: RVO:61388980 Keywords : Reservoirs * Multi-proxy stratigraphic analysis * Sediment accumulation rates * Heavy metals * Enrichment factors Subject RIV: DD - Geochemistry OBOR OECD: Geology Impact factor: 4.900, year: 2016

  3. Environmental Assessment, Repair of the Dam at Non-Potable Reservoir #1, United States Air Force Academy, Colorado

    Science.gov (United States)

    2015-08-01

    expected and are not analyzed further in this EA. Utilities. The electrical, natural gas, water, and sanitary sewer requirements of the Proposed...therefore, no increase in utility usage or sanitary and solid waste generation would occur. Utility connections that run alongside the existing dam...for evaluation of the soils suitability for native revegetation. An acceptable topsoil shall have a loam, sandy loam, clay loam, or silt loam texture

  4. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2001-2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, Richard; Williams, John G.; Smith, Steven G. (Northwest and Alaska Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    2002-06-01

    In 2001, the National Marine Fisheries Service and the University of Washington completed the ninth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from passive integrated transponder (PIT)-tagged fish. We PIT tagged and released at Lower Granite Dam a total of 17,028 hatchery and 3,550 wild steelhead. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream of the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using the Single-Release Model. Primary research objectives in 2001 were to: (1) estimate reach and project survival and travel time in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2001 for PIT-tagged yearling chinook salmon and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures with a minimum of text. More details on methodology and statistical models used are provided in previous reports cited in the text. Results for summer-migrating chinook salmon will be reported separately.

  5. Artificial dam lakes as suitable habitats for exotic invertebrates: Ostracoda ecology and distribution in reservoirs of the Eastern Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Escrivà A.

    2014-01-01

    Full Text Available Reservoirs are the most common deep lakes in Spain, as a consequence of water needs and dry climate. Although these aquatic systems can play an important ecological role in such an area with few large natural lakes, they can also provide new habitats for exotic species, which can colonize ecosystems that native species have not explored yet. Here we present our results for a biannual survey of the ostracod fauna from 24 reservoirs in Xúquer River basin. We check which variables affect ostracod presence, test for differences between winter and summer assemblages, and compare our data with previous available ostracod records from the same river drainage network. Our results reveal that ostracod presence is positively related to high diversity of the invertebrate community and reservoir volume, and negatively with phosphorus concentration. Among the 22 species found, it is noteworthy the first Iberian record of Ilyocypris getica and the second European record of Candonocypris novaezelandiae. Ostracod assemblages significantly vary between summer and winter, and strong differences are found between ostracod communities of reservoirs and those from their connected rivers. Remarkably higher frequency of exotic species in the reservoirs confirms previous findings about the facilitation that artificial ecosystems confer to aquatic invasions.

  6. Dam removal: Listening in

    Science.gov (United States)

    Foley, M. M.; Bellmore, J. R.; O'Connor, J. E.; Duda, J. J.; East, A. E.; Grant, G. E.; Anderson, C. W.; Bountry, J. A.; Collins, M. J.; Connolly, P. J.; Craig, L. S.; Evans, J. E.; Greene, S. L.; Magilligan, F. J.; Magirl, C. S.; Major, J. J.; Pess, G. R.; Randle, T. J.; Shafroth, P. B.; Torgersen, C. E.; Tullos, D.; Wilcox, A. C.

    2017-07-01

    Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

  7. Response of currents and water quality to changes in dam operations in Hoover Reservoir, Columbus, Ohio, August 24–28, 2015

    Science.gov (United States)

    Vonins, Branden L.; Jackson, P. Ryan

    2017-05-25

    Hoover Reservoir, an important drinking water supply for the City of Columbus, Ohio, has been the source of a series of taste and odor problems in treated drinking water during the past few years. These taste and odor problems were caused by the compounds geosmin and 2-methylisoborneol, which are thought to have been related to cyanobacteria blooms. In an effort to reduce the phosphorus available for cyanobacteria blooms at fall turnover, the City of Columbus began experimenting with the dam’s selective withdrawal system to remove excess phosphorus in the hypolimnion, which is released from bottom sediments during summer anoxic conditions.The U.S. Geological Survey completed two synoptic survey campaigns to assess distributions of water quality and water velocity in the lower part of Hoover Reservoir to provide information on the changes to reservoir dynamics caused by changing dam operations. One campaign (campaign 1) was done while water was being withdrawn from the reservoir through the dam’s middle gate and the other (campaign 2) while water was being withdrawn through the dam’s lower gate. Velocities were measured using an acoustic Doppler current profiler, and water-quality parameters were measured using an autonomous underwater vehicle equipped with water-quality sensors. Along with the water-quality and water-velocity data, meteorological, inflow and outflow discharges, and independent water-quality data were compiled to monitor changes in other parameters that affect reservoir behavior. Monthly nutrient data, collected by the City of Columbus, were also analyzed for trends in concentration during periods of expected stratification.Based on the results of the two campaigns, when compared to withdrawing water through the middle gate, withdrawing water through the lower gate seemed to increase shear-driven mixing across the thermocline, which resulted in an increase in the depth of the epilimnion throughout the lower part of Hoover Reservoir. The

  8. The effect of depth, distance from dam and habitat on spatial distribution of fish in an artificial reservoir

    Czech Academy of Sciences Publication Activity Database

    Prchalová, Marie; Kubečka, Jan; Čech, Martin; Frouzová, Jaroslava; Draštík, Vladislav; Hohausová, Eva; Jůza, Tomáš; Kratochvíl, Michal; Matěna, Josef; Peterka, Jiří; Říha, Milan; Tušer, Michal; Vašek, Mojmír

    2009-01-01

    Roč. 18, č. 2 (2009), s. 247-260 ISSN 0906-6691 R&D Projects: GA AV ČR(CZ) 1QS600170504; GA ČR(CZ) GA206/07/1392; GA MZe(CZ) QH81046 Institutional research plan: CEZ:AV0Z60170517 Keywords : horizontal distribution * vertical distribution * gillnet * reservoir * Cyprinidae * Percidae * redundancy analysis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.512, year: 2009

  9. Dams designed to fail

    Energy Technology Data Exchange (ETDEWEB)

    Penman, A. [Geotechnical Engineering Consultants, Harpenden (United Kingdom)

    2004-09-01

    New developments in geotechnical engineering have led to methods for designing and constructing safe embankment dams. Failed dams can be categorized as those designed to fail, and those that have failed unexpectedly. This presentation outlined 3 dam failures: the 61 m high Malpasset Dam in France in 1959 which killed 421; the 71 m high Baldwin Hills Dam in the United States in 1963 which killed 5; and, the Vajont Dam in Italy in 1963 which killed 2,600 people. Following these incidents, the International Commission for Large Dams (ICOLD) reviewed regulations on reservoir safety. The 3 dams were found to have inadequate spillways and their failures were due to faults in their design. Fuse plug spillways, which address this problem, are designed to fail if an existing spillway proves inadequate. They allow additional discharge to prevent overtopping of the embankment dam. This solution can only be used if there is an adjacent valley to take the additional discharge. Examples of fuse gates were presented along with their effect on dam safety. A research program is currently underway in Norway in which high embankment dams are being studied for overtopping failure and failure due to internal erosion. Internal erosion has been the main reason why dams have failed unexpectedly. To prevent failures, designers suggested the use of a clay blanket placed under the upstream shoulder. However, for dams with soft clay cores, these underblankets could provide a route for a slip surface and that could lead to failure of the upstream shoulder. It was concluded that a safe arrangement for embankment dams includes the use of tipping gates or overturning gates which always fail at a required flood water level. Many have been installed in old and new dams around the world. 14 refs., 19 figs.

  10. Evaluation of the hydraulic and biological performance of the portable floating fish collector at Cougar Reservoir and Dam, Oregon, 2014

    Science.gov (United States)

    Beeman, John W.; Evans, Scott D.; Haner, Philip V.; Hansel, Hal C.; Hansen, Amy C.; Hansen, Gabriel S.; Hatton, Tyson W.; Sprando, Jamie M.; Smith, Collin D.; Adams, Noah S.

    2016-01-12

    The biological and hydraulic performance of a new portable floating fish collector (PFFC) located in a cul-de-sac within the forebay of Cougar Dam, Oregon, was evaluated during 2014. The purpose of the PFFC was to explore surface collection as a means to capture juvenile salmonids at one or more sites using a small, cost-effective, pilot-scale device. The PFFC used internal pumps to draw attraction flow over an inclined plane about 3 meters (m) deep, through a flume at a design velocity of as much as 6 feet per second (ft/s), and to empty a small amount of water and any entrained fish into a collection box. Performance of the PFFC was evaluated at 64 cubic feet per second (ft3/s) (Low) and 109 ft3/s (High) inflow rates alternated using a randomized-block schedule from May 27 to December 16, 2014. The evaluation of the biological performance was based on trap catch; behaviors, locations, and collection of juvenile Chinook salmon (Oncorhynchus tshawytscha) tagged with acoustic transmitters plus passive integrated transponder (PIT) tags; collection of juvenile Chinook salmon implanted with only PIT tags; and untagged fish monitored near and within the PFFC using acoustic cameras. The evaluation of hydraulic performance was based on measurements of water velocity and direction of flow in the PFFC.

  11. Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hockersmith, Eric E.

    1999-03-01

    This report consists of two parts describing research activities completed during 1997 under Bonneville Power Administration Project Number 93-29. Part 1 provides reach survival and travel time estimates for 1997 for PIT-tagged hatchery steelhead and yearling chinook salmon in the Snake and Columbia Rivers. The results are reported primarily in the form of tables and figures with a minimum of text. More detailed information on methodology and the statistical models used in the analysis are provided in previous annual reports cited in the text. Analysis of the relationships among travel time, survival, and environmental factors for 1997 and previous years of the study will be reported elsewhere. Part 2 of this report describes research to determine areas of loss and delay for juvenile hatchery salmonids above Lower Granite Reservoir.

  12. War damages and reconstruction of Peruca dam

    International Nuclear Information System (INIS)

    Nonveiller, E.; Sever, Z.

    1999-01-01

    The paper describes the heavy damages caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the damages were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the damaged core in the central dam part as the impermeable dam element and to rebuild the central clay core at the dam abutments. Reconstruction works are described

  13. Smolt monitoring at the head of lower granite reservoir and lower Granite Dam, annual report 1999 operations.; ANNUAL

    International Nuclear Information System (INIS)

    United States. Bonneville Power Administration. Division of Fish and Wildlife; Idaho. Dept. of Fish and Game.

    2001-01-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 1999 spring out-migration at migrant traps on the Snake River and Salmon River. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1999. Total annual hatchery chinook salmon catch at the Snake River trap was 440% of the 1998 number. The wild chinook catch was 603% of the previous year's catch. Hatchery steelhead trout catch was 93% of 1998 numbers. Wild steelhead trout catch was 68% of 1998 numbers. The Snake River trap collected 62 age-0 chinook salmon. During 1998 the Snake River trap captured 173 hatchery and 37 wild/natural sockeye salmon and 130 hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations began on March 14 and were terminated for the season due to high flows on May 25. The trap was out of operation for 18 d during the season due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 214%, and wild chinook salmon catch was 384% of 1998 numbers. The hatchery steelhead trout collection in 1999 was 210% of the 1998 numbers. Wild steelhead trout collection in 1999 was 203% of the 1998 catch. Trap operations began on March 14 and were terminated for the season due to high flows on May 21. The trap was out of operation for 17 d during the season due to high flow and debris

  14. Smolt monitoring at the head of Lower Granite Reservoir and Lower Granite Dam, annual report 1997 operations.; ANNUAL

    International Nuclear Information System (INIS)

    United States. Bonneville Power Administration. Division of Fish and Wildlife.

    1999-01-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss smolts during the 1997 spring out-migration at migrant traps on the Snake River and Salmon River. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1997. Total annual hatchery chinook salmon catch at the Snake River trap was 49% of the 1996 number but only 6% of the 1995 catch. The wild chinook catch was 77% of the 1996 but was only 13% of 1995. Hatchery steelhead trout catch was 18% of 1996 numbers but only 7% of the 1995 numbers. Wild steelhead trout catch was 22% of 1996 but only 11% of the 1995 numbers. The Snake River trap collected eight age-0 chinook salmon and one sockeye/kokanee salmon O. nerka. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations were terminated for the season due to high flows and trap damage on May 8 and were out of operation for 23 d due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 37% and wild chinook salmon catch was 60% of 1996 numbers but only 5% and 11% of 1995 catch, respectively. The 1997 hatchery steelhead trout collection was 13% of the 1996 catch and 32% of the 1995 numbers. Wild steelhead trout collection in 1997 was 21% of the 1996 catch and 13% of the 1995 numbers. Trap operations were terminated for the season due to high flows and trap damage on May 7 and were out of operation for 19 d due to high flow and debris

  15. Survey of Potential Hanford Site Contaminants in the Upper Sediment for the Reservoirs at McNary, John Day, The Dalles, and Bonneville Dams, 2003

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Gregory W.; Priddy, M; Yokel, Jerel W.; Delistraty, Damon A.; Stoops, Thomas M.

    2005-02-01

    This report presents the results from a multi-agency cooperative environmental surveillance study. of the study looked at sediment from the pools upstream from dams on the Columbia River that are downstream from Hanford Site operations. The radiological and chemical conditions existing in the upper-level sediment found in the pools upstream from McNary Dam, John Day Dam, The Dalles Lock and Dam, and Bonneville Dam were evaluated. This study also evaluated beach sediment where available. Water samples were collected at McNary Dam to further evaluate potential Hanford contaminants in the lower Columbia River. Samples were analyzed for radionuclides, chemicals, and physical parameters. Results from this study were compared to background values from sediment and water samples collect from the pool upstream of Priest Rapids Dam (upstream of the Hanford Site) by the Hanford Site Surface Environmental Surveillance Project.

  16. 33 CFR 80.501 - Tom's River, NJ to Cape May, NJ.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tom's River, NJ to Cape May, NJ. 80.501 Section 80.501 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Fifth District § 80.501 Tom's River, NJ to Cape May, NJ...

  17. A GIS based approach for the prediction of the dam break flood hazard – A case study of Zardezas reservoir “Skikda, Algeria”

    Directory of Open Access Journals (Sweden)

    Derdous Oussama

    2015-12-01

    Full Text Available The construction of dams in rivers can offer many advantages, however the consequences resulting from their failure could result in major damage, including loss of life and property destruction. To mitigate the threats of dam break it is essential to appreciate the characteristics of the potential flood in realistic manner. In this study an approach based on the integration of hydraulic modelling and GIS has been used to assess the risks resulting from a potential failure of Zardezas dam, a concrete dam located in Skikda, in the North East of Algeria. HEC-GeoRAS within GIS was used to extract geometric information from a digital elevation model and then imported into HEC-RAS. Flow simulation of the dam break was performed using HEC-RAS and results were mapped using the GIS. Finally, a flood hazard map based on water depth and flow velocity maps was created in GIS environment. According to this map the potential failure of Zardezas dam will place a large number in people in danger. The present study has shown that Application of Geographical Information System (GIS techniques in integration with hydraulic modelling can significantly reduce the time and the resources required to forecast potential dam break flood hazard which can play a crucial role in improving both flood disaster management and land use planning downstream of dams.

  18. Moisture and temperature in a proppant-enveloped silt block of a recharge dam reservoir: Laboratory experiment and 1-D mathematical modelling

    Directory of Open Access Journals (Sweden)

    Anvar Kacimov

    2018-01-01

    Full Text Available Mosaic 3-D cascade of parallelepiped-shaped silt blocks, which sandwich sand- lled cracks, has been discovered in the eld and tested in lab experiments. Controlled wetting-drying of these blocks, collected from a dam reservoir, mimics field ponding-desiccation conditions of the topsoil layer subject to caustic solar radiation, high temperature and wind, typical in the Batinah region of Oman. In 1-D analytical modelling of a transient Richards’ equation for vertical evaporation, the method of small perturbations is applied, assuming that the relative permeability is Avery-anov’s 3.5-power function of the moisture content and capillary pressure is a given (measured function. A linearized advective dispersion equation is solved with respect to the second term in the series expansion of the moisture content as a function of spatial coordinates and time. For a single block of a nite thickness we solve a boundary value problem with a no- ow condition at the bottom and a constant moisture content at the surface. Preliminary comparisons with theta-, TDR- probes measuring the moisture content and temperature at several in-block points are made. Results corroborate that a 3-D heterogeneity of soil physical properties, in particular, horizontal and vertical capillary barriers emerging on the interfaces between silt and sand generate eco-niches with stored soil water compartments favourable for lush vegetation in desert conditions. Desiccation significantly increases the temperature in the blocks and re-wetting of the blocks reduces the daily average and peak temperatures, the latter by almost 15°C. This is important for planning irrigation in smartly designed soil substrates and sustainability of wild plants in the region where the top soil peak temperature in the study area exceeds 70°C in Summer but smartly structured soils maintain lash vegetation. Thee layer of dry top-blocks acts as a thermal insulator for the subjacent layers of wet blocks that

  19. Health impacts of large dams

    International Nuclear Information System (INIS)

    Lerer, L.B.

    1999-01-01

    Large dams have been criticized because of their negative environmental and social impacts. Public health interest largely has focused on vector-borne diseases, such as schistosomiasis, associated with reservoirs and irrigation projects. Large dams also influence health through changes in water and food security, increases in communicable diseases, and the social disruption caused by construction and involuntary resettlement. Communities living in close proximity to large dams often do not benefit from water transfer and electricity generation revenues. A comprehensive health component is required in environmental and social impact assessments for large dam projects

  20. 33 CFR 80.170 - Sandy Hook, NJ to Tom's River, NJ.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sandy Hook, NJ to Tom's River, NJ. 80.170 Section 80.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.170 Sandy Hook, NJ to Tom's River...

  1. Prediction of downstream geomorphological changes after dam construction: A stream power approach

    DEFF Research Database (Denmark)

    Brandt, Anders

    2000-01-01

    physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry......physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry...

  2. Seston fluxes in the dam of a Colombian tropical reservoir Fluxos de seston na barragem de um reservatório tropical Colombiano

    Directory of Open Access Journals (Sweden)

    Yimmy Montoya Moreno

    2010-09-01

    Full Text Available AIM: Quantify sedimentation rates in Rio Grande II reservoir, his temporal fluctuation, and the degree of mineralization of the material that reaches the sediment; METHODS: A system of five sedimentation traps was used to evaluate temporal variability of seston flux and the total sedimentation in the dam of Río Grande II reservoir Antioquia-Colombia (6° 32, 62' N, 75° 27, 27' W; RESULTS: The flux total solids presented a mean value of 4540 g.m-2.d-1 with a range oscillating between 229 and 18573 g.m-2.d-1, being the fixed and suspended fraction the most of the total solids. It was evidenced that the largest fluxes were presented between the fourth and the fifth trap (the nearest to the bottom due to hypolimnetic fluxes which contain materials of the tributaries and resuspended material. The first three traps collected particles that settled from the column of water without evaluate the overtrapping for resuspension. In some samplings the mineralization between the third and fourth trap was maximum (100%. The fluxes of seston particles presented a mean value of 3554 g.m-2.d-1 with a range between 810 and 18955 g.m-2.d-1, being predominant the inorganic fraction; CONCLUSIONS: The seston is mainly of allochthonous origin and variated in the time and in the vertical level. There was not found a significant relationship between level of the reservoir and the mixing depth with the fluxes of total sedimentation and seston; however there was relation between seston concentration and wind speed.OBJETIVO: Quantificar taxas de sedimentação no reservatório do Rio Grande II, sua flutuação temporal, bem como o grau de mineralização do material que chega ao sedimento; MÉTODOS: Foi utilizado um sistema de cinco armadilhas de sedimentação para avaliar a variabilidade temporal do fluxo total de seston e a sedimentação no reservatório Rio Grande II, Antioquia-Colombia (6° 32, 62' N, 75° 27, 27' W; RESULTADOS: Fluxos de seston na barragem de um

  3. Dynamic tests at the Outardes 3 dam

    International Nuclear Information System (INIS)

    Proulx, J.; Paultre, P.; Duron, Z.; Tai Mai Phat; Im, O.

    1992-01-01

    At the Outardes 3 gravity dam, part of the Manicouagan-Outardes hydroelectric complex in northeastern Quebec, forced vibration tests were carried out using an eccentric mass shaker attached to the dam crest at three different locations. Accelerations were measured along the crest and in the inspection galleries, and hydrodynamic pressures were measured along the upstream dam face and at various locations in the reservoir. The tests were designed to analyze the effects of gravity dam-reservoir interactions and to generate a data base for calibrating finite element models used in studying the dynamic behavior of gravity dams. Experimental results are presented in order to demonstrate the quality of the data obtained and the effectiveness of the experimental procedures. Modes of vibration were observed which corresponded to those obtained by finite element analysis. It is shown that techniques recently developed for dynamic tests on large dams can be successfully used on gravity dams. 3 refs., 6 figs

  4. Assessment of dam construction impact on hydrological regime changes in lowland river – A case of study: the Stare Miasto reservoir located on the Powa River

    Directory of Open Access Journals (Sweden)

    Sojka Mariusz

    2016-09-01

    Full Text Available The purpose of the presented research is analysis and assessment of the Stare Miasto reservoir impact on the hydrological regime changes of the Powa River. The reservoir was built in 2006 and is located in the central part of Poland. The total area of inundation in normal conditions is 90.68 ha and its capacity is 2.159 mln m3. Hydrological regime alteration of the Powa River is analysed on the basis of daily flows from the Posoka gauge station observed during period 1974–2014. Assessment of hydrological regime changes is carried out on the basis of Range of Variability Approach (RVA method. All calculations are made by means of Indicators of Hydrologic Alteration (IHA software version 7.1.0.10. The analysis shows that the Stare Miasto reservoir has a moderate impact on hydrological regime of the Powa River. Construction of the reservoir has positive effect on stability of minimal flows, which are important for protection of river ecosystems. The results obtained indicate that the Stare Miasto reservoir reduces a spring peak flow and enables to moderate control of floods.

  5. National Program for Inspection of Non-Federal Dams. Bearhole Reservoir (MA 00073), Westfield River Basin, West Springfield, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1981-06-01

    SAutomatic . Manual I . Operative Yes I , No Co~ents: All controls operable per Water Departxent oersonnel. I Drawdown present Yes I , No Operative Yes_ , No... controls a 6-inch valve for dewatering the raw water wet well. One raw water supply gate was fully opened; the other opened 1-inch, and the 24-inch outlet...development). ,B- I B-2 w J---.-.z-- OtL ’S: OT7LET CONTROLS AND DRADMN Westerly end of dam - conc. overflow D.I. sluiceway No. Location and T7pe:I2

  6. Dworshak Dam impacts assessment and fisheries investigation -- Kokanee depth distribution in Dworshak Reservoir and implications toward minimizing entrainment. Annual progress report, January--December 1994

    International Nuclear Information System (INIS)

    Maiolie, M.A.; Elam, S.

    1996-10-01

    The authors measured the day and night depth distribution of kokanee Oncorhynchus nerka kennerlyi directly upstream of Dworshak Dam from October 1993 to December 1994 using split-beam hydroacoustics. At night most kokanee (70%) were distributed in a diffuse layer about 10 m thick. The depth of the layer varied with the season and ranged from 30 to 40 m deep during winter and from 15 to 25 m deep during summer. Nighttime depth of the kokanee layer during summer roughly corresponded to a zone where water temperatures ranged from 7 C to 12 C. Daytime kokanee distribution was much different with kokanee located in dense schools. Most kokanee (70%) were found in a 5--15 m thick layer during summer. Daytime depth distribution was also shallowest during fall and deepest during winter. Dworshak Dam has structures which can be used for selective water withdrawal and can function in depth ranges that will avoid the kokanee layer. Temperature constraints limit the use of selective withdrawal during the spring, summer, and fall, but in the winter, water is nearly isothermal and the full range of selector gate depths may be utilized. From October 1993 to February 1994, selector gates were positioned to withdraw water from above the kokanee layer. The discharge pattern also changed with more water being released during May and July, and less water being released during fall and winter. A combination of these two changes is thought to have increased kokanee densities to a record high of 69 adults/ha

  7. Applying 1D Sediment Models to Reservoir Flushing Studies: Measuring, Monitoring, and Modeling the Spencer Dam Sediment Flush with HEC-RAS

    Science.gov (United States)

    2016-07-01

    by Paul Boyd and Stanford Gibson PURPOSE: The purposes of this Coastal and Hydraulics Engineering Technical Note (CHETN) are (1) to summarize the...HEC-RAS), and (2) to determine the model’s applicability for flushing applications. HEC-RAS is a one- dimensional (1D) numerical hydraulics and... reduces the usable space in Federal reservoirs and depletes downstream reaches of ecologically important substrates. The USACE and other Federal agencies

  8. Physical and biological responses to an alternative removal strategy of a moderate-sized dam in Washington, USA.

    Science.gov (United States)

    Shannon Claeson; B. Coffin

    2015-01-01

    Dam removal is an increasingly practised river restoration technique, and ecological responses vary with watershed, dam and reservoir properties, and removal strategies. Moderate-sized dams, like Hemlock Dam (7.9m tall and 56m wide), are large enough that removal effects could be significant, but small enough that mitigation may be possible through a modified dam...

  9. On the response of large dams to incoherent seismic excitation

    International Nuclear Information System (INIS)

    Ramadan, O.; Novak, M.

    1993-01-01

    An intensive parametric study was conducted to investigate the response of concrete gravity dams to horizontal, spatially variable seismic ground motions. Both segmented dams consisting of separate blocks, or monoliths, and continuous monolithic dams are considered. The study includes the effects of various parameters on system natural frequencies, vibration modes, modal displacement ratios, as well as dam displacements and internal stresses due to spatially variable ground motions. The dam analytical model, and dam response to incoherent ground motions are described. The results show that the dam vibrates almost as a rigid body under the fully correlated waves, but bends and twists significantly under the spatially correlated motions. Dam-foundation interaction magnifies the low frequency components of the dam response, more so for a full reservoir, but decreases the high frequency components. For long dams, the effects of spatially incoherent ground motions are qualitatively different and can be much greater than those due to surface travelling waves. 3 refs., 3 figs

  10. Alpine dams

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  11. Physicochemical characteristics of undrainable water dams utilized ...

    African Journals Online (AJOL)

    pH, electro-conductivity and total dissoved solutes (TDS) were measured in-situ from three reservoirs (Gathathini, Lusoi and Kianda dams) differing in their habitat characteristics. Water samples were collected for determination of the ionic concentartions of the reservoirs. Water quality status differed markedly between sites, ...

  12. Dredged Material Management Plan and Environmental Impact Statement. McNary Reservoir and Lower Snake River Reservoirs. Appendix C: Economic Analysis

    National Research Council Canada - National Science Library

    2002-01-01

    ...; for managment of dredged material from these reservoirs; and for maintenance of flow conveyance capacity at the most upstream extent of the Lower Granite reservoir for the remaining economic life of the dam and reservoir project (to year 2074...

  13. The changing hydrology of a dammed Amazon

    Science.gov (United States)

    Timpe, Kelsie; Kaplan, David

    2017-01-01

    Developing countries around the world are expanding hydropower to meet growing energy demand. In the Brazilian Amazon, >200 dams are planned over the next 30 years, and questions about the impacts of current and future hydropower in this globally important watershed remain unanswered. In this context, we applied a hydrologic indicator method to quantify how existing Amazon dams have altered the natural flow regime and to identify predictors of alteration. The type and magnitude of hydrologic alteration varied widely by dam, but the largest changes were to critical characteristics of the flood pulse. Impacts were largest for low-elevation, large-reservoir dams; however, small dams had enormous impacts relative to electricity production. Finally, the “cumulative” effect of multiple dams was significant but only for some aspects of the flow regime. This analysis is a first step toward the development of environmental flows plans and policies relevant to the Amazon and other megadiverse river basins. PMID:29109972

  14. Sinkhole remediation at Swinging Bridge Dam

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. [Devine Tarbell and Associates, Portland, ME (United States)

    2009-07-01

    This case history summary described a piping-related sinkhole that occurred after a flood at the Swinging Bridge Dam. The earth-filled embankment dam was constructed using a hydraulic fill technique. A foundation drilling and grouting program was constructed in areas of the dam founded on jointed sandstone and shale. The storage volumes of the reservoir is 32,000 acre-feet. A sinkhole 25 to 300 feet in diameter was observed on May 5, 2005 along the edge of the dam crest. The sinkhole extended to within 10 feet of the reservoir and was separated by a shallow berm of soil and driftwood. Cracking of the crest extended across an area of 180 feet. Operations staff notified the appropriate agencies, implemented a monitoring program, and mobilized construction equipment and sands for use as emergency sinkhole filler. An increase in tailrace turbidity was observed. Historical records for the dam showed significant cracking during the initial filling of the reservoir. Failure modes included increased pore pressures and seepages resulting in the piping of soil along the outside of the dam conduit. Emergency repairs included chemical grouting and weld repairs in the penstocks. A Federal Emergency Management Agency (FEMA) is currently addressing safety issues associated with conduits through dams. 4 refs., 11 figs.

  15. Dam spills and fishes

    International Nuclear Information System (INIS)

    1996-01-01

    This short paper reports the main topics discussed during the two days of the annual colloquium of the Hydro-ecology Committee of EdF. The first day was devoted to the presentation of the joint works carried out by EdF, the Paul-Sabatier University (Toulouse), the Provence St-Charles University (Marseille), the ENSAT (Toulouse) and the CEMAGREF (Lyon and Aix-en-Provence) about the environmental impact of dam spills on the aquatic flora and fauna downstream. A synthesis and recommendations were presented for the selection and characterization of future sites. The second day was devoted to the hydro-ecology study of the dam reservoir of Petit-Saut (French Guyana): water reoxygenation, quality evolution, organic matter, plankton, invertebrates and fishes. The 134 French dams concerned by water spills have been classified according to the frequency of spills, the variations of flow rates created, and their impacts on fishing, walking, irrigation, industry, drinking water, navigation, bathing. Particular studies on different sites have demonstrated the complexity of the phenomena involved concerning the impact on the ecosystems and the water quality. (J.S.)

  16. Assessment of Climate Change Impact on Reservoir Inflows Using Multi Climate-Models under RCPs—The Case of Mangla Dam in Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Babur

    2016-09-01

    Full Text Available Assessment of climate change on reservoir inflow is important for water and power stressed countries. Projected climate is subject to uncertainties related to climate change scenarios and Global Circulation Models (GCMs. This paper discusses the consequences of climate change on discharge. Historical climatic and gauging data were collected from different stations within a watershed. Bias correction was performed on GCMs temperature and precipitation data. After successful development of the hydrological modeling system (SWAT for the basin, streamflow was simulated for three future periods (2011–2040, 2041–2070, and 2071–2100 and compared with the baseline data (1981–2010 to explore the changes in different flow indicators such as mean flow, low flow, median flow, high flow, flow duration curves, temporal shift in peaks, and temporal shifts in center-of-volume dates. From the results obtained, an overall increase in mean annual flow was projected in the basin under both RCP 4.5 and RCP 8.5 scenarios. Winter and spring showed a noticeable increase in streamflow, while summer and autumn showed a decrease in streamflow. High flows were predicted to increase, but median flow was projected to decrease in the future under both scenarios. Flow duration curves showed that the probability of occurrence of high flow is likely to be more in the future. It was also noted that peaks were predicted to shift from May to July in the future, and the center-of-volume date of the annual flow may vary from −11 to 23 days in the basin, under both RCP 4.5 and RCP 8.5. As a whole, the Mangla basin will face more floods and less droughts in the future due to the projected increase in high and low flows, decrease in median flows and greater temporal and magnitudinal variations in peak flows. These outcomes suggest that it is important to consider the influence of climate change on water resources to frame appropriate guidelines for planning and management.

  17. Dam Safety Concepts

    NARCIS (Netherlands)

    Duricic, J.

    2014-01-01

    The majority of dams constructed in the world are dams that can be categorized as embankment dams. Throughout history we can point to many failures of dams, and embankment dams in particular. Nowadays it is clear that the goal to construct stable dams has not been achieved, even with advanced

  18. Seismic risks at Elsie Lake Main Dam

    International Nuclear Information System (INIS)

    McCammon, N.R.; Momenzadeh, M.; Hawson, H.H.; Nielsen, N.M.

    1991-01-01

    The Elsie Lake dams are located on Vancouver Island in an area of high seismic risk. A safety review in 1986 indicated potential deficiencies in the earthfill main dam with respect to modern earthquake design standards. A detailed field investigation program comprising drilling and penetration tests was carried out and the results used in an assessment of seismic stability. A 0.8 m thick less dense layer in the granular shell of the dam, possibly caused by wet construction conditions, would likely liquefy in a major earthquake but sufficient residual strength would likely remain to prevent catastrophic failure. The dam shell might undergo some distortion, and an assessment was initiated to determine the requirements for reservoir drawdown following an extreme earthquake to ensure the timely lowering of the reservoir for inspection and repair. It was suggested that an adequate evacuation capability would be 25% and 50% drawdown in not more than 30 and 50 days, respectively. 9 refs., 11 figs., 1 tab

  19. Safety Aspects of Sustainable Storage Dams and Earthquake Safety of Existing Dams

    Directory of Open Access Journals (Sweden)

    Martin Wieland

    2016-09-01

    Full Text Available The basic element in any sustainable dam project is safety, which includes the following safety elements: ① structural safety, ② dam safety monitoring, ③ operational safety and maintenance, and ④ emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. However, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be carried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that dam safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.

  20. Brazil's Amazonian dams: Ecological and socioeconomic impacts

    Science.gov (United States)

    Fearnside, P. M.

    2016-12-01

    Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with environmental and socioeconomic impacts. Loss of forest to flooding is one, the Balbina and Tucuruí Dams being examples (each 3000 km2). If the Babaquara/Altamira Dam is built it will flood as much forest as both of these combined. Some planned dams imply loss of forest in protected areas, for example on the Tapajós River. Aquatic and riparian ecosystems are lost, including unique biodiversity. Endemic fish species in rapids on the Xingu and Tapajós Rivers are examples. Fish migrations are blocked, such as the commercially important "giant catfish" of the Madeira River. Dams emit greenhouse gases, including CO2 from the trees killed and CH4 from decay under anoxic conditions at the bottom of reservoirs. Emissions can exceed those from fossil-fuel generation, particularly over the 20-year period during which global emissions must be greatly reduced to meet 1.5-2°C limit agreed in Paris. Carbon credit for dams under the Climate Convention causes further net emission because the dams are not truly "additional." Anoxic environments in stratified reservoirs cause methylation of mercury present in Amazonian soils, which concentrates in fish, posing a health risk to human consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country's power. Losses in transmission lines (20%) are far above global averages and can be

  1. The Total Risk Analysis of Large Dams under Flood Hazards

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2018-02-01

    Full Text Available Dams and reservoirs are useful systems in water conservancy projects; however, they also pose a high-risk potential for large downstream areas. Flood, as the driving force of dam overtopping, is the main cause of dam failure. Dam floods and their risks are of interest to researchers and managers. In hydraulic engineering, there is a growing tendency to evaluate dam flood risk based on statistical and probabilistic methods that are unsuitable for the situations with rare historical data or low flood probability, so a more reasonable dam flood risk analysis method with fewer application restrictions is needed. Therefore, different from previous studies, this study develops a flood risk analysis method for large dams based on the concept of total risk factor (TRF used initially in dam seismic risk analysis. The proposed method is not affected by the adequacy of historical data or the low probability of flood and is capable of analyzing the dam structure influence, the flood vulnerability of the dam site, and downstream risk as well as estimating the TRF of each dam and assigning corresponding risk classes to each dam. Application to large dams in the Dadu River Basin, Southwestern China, demonstrates that the proposed method provides quick risk estimation and comparison, which can help local management officials perform more detailed dam safety evaluations for useful risk management information.

  2. Verifying Pressure of Water on Dams, a Case Study

    Directory of Open Access Journals (Sweden)

    Temel Bayrak

    2008-09-01

    Full Text Available Sensing and monitoring deformation pattern of dams is often one of the most effective ways to understand their safety status. The main objective of the present study is to find the extent to which rising reservoir level affects the mechanism of deformation of the Yamula dam under certain changes in the reservoir level conditions during the first filling period. A new dynamic deformation analysis technique was developed to analyze four geodetic monitoring records consisting of vertical and horizontal displacements of nine object points established on the dam and six reference points surrounding it, to see whether the rising reservoir level is responsible for the vertical and horizontal deformations during the first filling period. The largest displacements were determined in the middle points of the dam construction. There is an apparent linear relationship between the dam subsidence and the reservoir level. The dynamic deformation model was developed to model this situation. The model infers a causative relationship between the reservoir level and the dam deformations. The analysis of the results determines the degree of the correlation between the change in the reservoir level and the observed structural deformation of the dam.

  3. Japan`s largest composition dam, aiming for harmony with nature. Chubetsu dam; Shizen tono chowa wo mezasu, Nippon ichi no fukugo dam. Chubetsu dam

    Energy Technology Data Exchange (ETDEWEB)

    Mizushima, T. [Hokkaido Development Bureau, Hokkaido Development Agency, Sapporo (Japan)

    1994-08-15

    This paper introduces Chubetsu Dam planned with a large-scale embankment having a river bed width of 600 m. Chubetsu Dam is being constructed with such objectives as flood control of Ishikari River, river flow rate maintenance, drinking water supply, irrigation water supply and power generation. The dam site is a gravel bed having a river bed width of 600 m and a maximum foundation rock thickness of 40 m, requiring evaluations as a dam foundation and discussions of water shielding methods. As a result of discussions at the Chubetsu Dam technical discussion committee, the dam type is decided to be a composition dam consisting of a gravity type concrete dam on the left river side and a central core type fill dam using a part of the gravel bed as the foundation on the right river side. A continuous underground wall system is planned to be used for shielding water in the gravel foundation. In discussing the anti-seismic properties, analyses for bank construction and water filling to derive stress and deformation conditions prior to an earthquake and a time-history response analysis to derive conditional changes during the earthquake are performed. According to the results thereof, evaluations are given on the safety by compounding the stress and the acceleration. In plans to improve the surrounding areas, an area will be provided upstream the reservoir where the water level is kept constant to serve as a bird sanctuary. 7 figs.

  4. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  5. Sandia and NJ TRANSIT Authority Developing Resilient Power Grid

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Charles J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-11-01

    Through the memorandum of understanding between the Depratment of Energy (DOE), the New Jersey Transit Authority (NJ Transit), and the New Jersey Board of Public Utilities, Sandia National Labs is assisting NJ Transit in developing NJ TransitGrid: an electric microgrid that will include a large-scale gas-fired generation facility and distributed energy resources (photovoltaics [PV], energy storage, electric vehicles, combined heat and power [CHP]) to supply reliable power during storms or other times of significant power failure. The NJ TransitGrid was awarded $410M from the Department of Transportation to develop a first-of-its-kind electric microgrid capable of supplying highly-reliable power.

  6. Large dams and risk management

    International Nuclear Information System (INIS)

    Cazelais, N.

    2003-01-01

    In July 1996, Quebec's Saguenay region was subjected to intensive rainfall which caused severe floods and uncontrolled release of several reservoirs, resulting in extensive damage to dam structures and reservoirs. The probability of occurrence for that disaster was 1:10,000. Following the disaster, the Quebec government established a dam management body entitled the Commission scientifique et technique sur la gestion des barrages, which pointed out several safety shortcomings of existing dams. Many were either very old or had undergone significant function change without being subsequently re-evaluated. A report by the Commission stated that damage following the floods could have been limited if the design and operating standards of the dams had been more stringent. A Dam Safety Act was adopted by the Quebec National Assembly on May 30, 2000 following recommendations to retain safer structures. The Act demands regular reporting of operating procedures. Seismic activity was noted as being a topic that requires in-depth examination since Quebec's St. Lawrence Valley, particularly the Charlevoix region, is one of Canada's largest seismic zones. The other is on the west coast in British Columbia. Earthquakes in Quebec are less intense than the ones in British Columbia, but they have higher frequency content which exerts a quasi-resonance wave effect which impacts roads, bridges, buildings and hydroelectric generating facilities. Hydro-Quebec is a public utility which owns 563 retaining structures, of which 228 are ranked as large dams that measure more than 15 metres high, 400 metres long and with a reservoir capacity of more than 1 million cubic metres of water. Hydro-Quebec addresses hydrological, seismic, technological and human risks through a dam safety procedure that includes structured plans for choosing best alternatives through staged exercises. Hazard levels are minimized through the adoption of emergency, prevention and alleviation measures. The utility

  7. Dissolved methane in Indian freshwater reservoirs

    Digital Repository Service at National Institute of Oceanography (India)

    Narvenkar, G.; Naqvi, S.W.A.; Kurian, S.; Shenoy, D.M.; Pratihary, A.K.; Naik, H.; Patil, S.; Sarkar, A.; Gauns, M.

    of the central part of the Indo- Gangetic Plain just north of the Tropic of Cancer. The eighth – the Bhakra-Nangal Dam is built over the Sutlej River at the foothills of the Himalayas. The reservoirs of these dams vary greatly in size from very small systems...

  8. Pine Flat Dam Fish and Wildlife Habitat Restoration, Fresno, California. Final Environmental Impact Statement/Environment Impact Report (SCH #96042044)

    National Research Council Canada - National Science Library

    2001-01-01

    ...; and reestablishing the historic flood plain and native historic plant and wildlife communities. This final EIS/EIR describes the environment near Pine Flat Dam and Reservoir and along the Lower Kings River in the Pine Flat Dam area...

  9. A study on the effect of a broken large sabo dam on the sediment transportation in channel - an example of Baling-sabo-dam

    Science.gov (United States)

    Tseng, W. H.; Shieh, C. L.; Lee, S. P.; Tsang, Y. C.

    2009-04-01

    To retard the sediment transportation and its effect on the reservoir, large sabo dams are built in the main channel of the reservoir watershed in Taiwan. Therefore, these large sabo dams affect upstream, downstream, and the reservoir significantly if the dam breaks. There was about 450 mm of rain fell in the reservoir watershed during typhoon Wipha that struck Taiwan on 17-19, September, 2007. This heavy rainfall caused the Baling-sabo-dam broken about 60 m of the upper Dahan Creek in the Shimen Reservoir watershed. The dam, built in 1977, is 38 m in height, 80 m in width, and is designed to reserve sediment materials about 10 million m3. The upper river bed was diminished maximum to 20 m in a month; the deposited and affected areas are unable to estimate and still required to be observed. The main purpose of this paper is to analyze the topographic characteristic of the channel after the dam broke according to the topographic and surveyed data before and after the dam broke. The longitudinal profile and the cross section data show the effects to the channel after the dam break and the channel is able to classify in several sections. A simple comparison of the sediment discharge estimated from the hydrologic data with the topographic survey data is also analyzed. Keywords:dam break, sabo dam, sediment discharge

  10. 77 FR 57022 - Drawbridge Operation Regulation; Shark River, Avon, NJ

    Science.gov (United States)

    2012-09-17

    ... Operation Regulation; Shark River, Avon, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation... across the Shark River (South Channel), at Avon Township, NJ. This deviation is necessary to facilitate stringer replacement on the Shark River railroad bridge. This temporary deviation will allow the...

  11. 78 FR 3836 - Drawbridge Operation Regulation; Shark River, Avon, NJ

    Science.gov (United States)

    2013-01-17

    ... Operation Regulation; Shark River, Avon, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from... and the railroad bridge, mile 0.9 both of which are across the Shark River (South Channel), at Avon Township, NJ. This deviation is necessary to facilitate machinery replacement on the Shark River railroad...

  12. National Program for Inspection of Non-Federal Dams. Tihonet Pond Number 2 Dam (MA 00030), Massachusetts Coastal Basin, Wareham, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1981-07-01

    drainage area above the dam is 8.1 square miles. The watershed is characterized by irregular topography: cranberry bogs, small ponds and depressions ...and recreational purposes. Water from this pond is used in the U irrigation of cranberry bogs downstream. The maximum storage capacity of the dam is...295-1000 g. PURPOSE OF DAM The dam impounds Tihonet Pond which is a storage reservoir 4_- 4 4: . * used principally for irrigating cranberry bogs which

  13. study and analysis of asa river hypothetical dam break using hec-ras

    African Journals Online (AJOL)

    Impounded reservoirs provide beneficial functions such as flood control, recreation, hydropower and water supply but they also carry potential risks. Spontaneous dam break phenomenon can occur and the resultant flooding may cause substantial loss of life and property damage downstream of the dam. A hypothetical dam ...

  14. NRC inventory of dams

    International Nuclear Information System (INIS)

    Lear, G.E.; Thompson, O.O.

    1983-01-01

    The NRC Inventory of Dams has been prepared as required by the charter of the NRC Dam Safety Officer. The inventory lists 51 dams associated with nuclear power plant sites and 14 uranium mill tailings dams (licensed by NRC) in the US as of February 1, 1982. Of the 85 listed nuclear power plants (148 units), 26 plants obtain cooling water from impoundments formed by dams. The 51 dams associated with the plants are: located on a plant site (29 dams at 15 plant sites); located off site but provide plant cooling water (18 dams at 11 additional plant sites); and located upstream from a plant (4 dams) - they have been identified as dams whose failure, and ensuing plant flooding, could result in a radiological risk to the public health and safety. The dams that might be considered NRC's responsibility in terms of the federal dam safety program are identified. This group of dams (20 on nuclear power plant sites and 14 uranium mill tailings dams) was obtained by eliminating dams that do not pose a flooding hazard (e.g., submerged dams) and dams that are regulated by another federal agency. The report includes the principal design features of all dams and related useful information

  15. Seasonal occurrence of anoxygenic photosynthesis in Tillari and Selaulim reservoirs, Western India

    Digital Repository Service at National Institute of Oceanography (India)

    Kurian, S.; Roy, R.; Repeta, D.J.; Gauns, M.; Shenoy, D.M.; Suresh, T.; Sarkar, A.; Narenkar, G.; Johnson, C.G.; Naqvi, S.W.A.

    Phytoplankton and bacterial pigment compositions were determined by high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) in two freshwater reservoirs (Tillari Dam and Selaulim Dam), which are located...

  16. Post-dam Channel and Floodplain Adjustment along the Lower Volga River, Russia

    NARCIS (Netherlands)

    Middelkoop, Hans; Alabyan, Andrei M; Babich, Dmitry B; Ivanov, Vadim V

    2015-01-01

    The Volga River in the Russian Federation has been regulated by a cascade of reservoir dams since the 1950–1960s. This chapter presents an overview of the main hydrological and morphological responses of the Volga River downstream of the Volgograd reservoir dam. Regulation caused a decrease in

  17. Factors influencing hysteresis characteristics of concrete dam deformation

    Directory of Open Access Journals (Sweden)

    Jia-he Zhang

    2017-04-01

    Full Text Available Thermal deformation of a concrete dam changes periodically, and its variation lags behind the air temperature variation. The lag, known as the hysteresis time, is generally attributed to the low velocity of heat conduction in concrete, but this explanation is not entirely sufficient. In this paper, analytical solutions of displacement hysteresis time for a cantilever beam and an arch ring are derived. The influence of different factors on the displacement hysteresis time was examined. A finite element model was used to verify the reliability of the theoretical analytical solutions. The following conclusions are reached: (1 the hysteresis time of the mean temperature is longer than that of the linearly distributed temperature difference; (2 the dam type has a large impact on the displacement hysteresis time, and the hysteresis time of the horizontal displacement of an arch dam is longer than that of a gravity dam; (3 the reservoir water temperature variation lags behind of the air temperature variation, which intensifies the differences in the horizontal displacement hysteresis time between the gravity dam and the arch dam; (4 with a decrease in elevation, the horizontal displacement hysteresis time of a gravity dam tends to increase, whereas the horizontal displacement hysteresis time of an arch dam is likely to increase initially, and then decrease; and (5 along the width of the dam, the horizontal displacement hysteresis time of a gravity dam decreases as a whole, while the horizontal displacement hysteresis time of an arch dam is shorter near the center and longer near dam surfaces.

  18. The Dams and Monitoring Systems and Case Study: Ataturk and Karakaya Dams

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.; Gülnerman, A. G.

    2017-12-01

    Dams are among the most important engineering structures used for flood controls, agricultural purposes as well as drinking and hydroelectric power. Especially after the Second World War, developments on the construction technology, increase the construction of larger capacity dams. There are more than 150.000 dams in the world and almost 1000 dams in Turkey, according to international criteria. Although dams provide benefits to humans, they possess structural risks too. To determine the performance of dams on structural safety, assessing the spatial data is very important. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some general information on dams and their different monitoring systems by taking into account two different dams and their structural specifications with the required information. The case study in this paper depends on a comparison of the monitoring surveys on Atatürk Dam and Karakaya Dam, which are constructed on Firat River with two different structural

  19. TYPOLOGY OF LARGE DAMS. A REVIEW

    Directory of Open Access Journals (Sweden)

    Gheorghe ROMANESCU

    2015-06-01

    Full Text Available The dams represent hydrotechnical constructions meant to ensure a judicious use of water resources. The international literature is extremely rich in data regarding the large dams on Earth. In this context, a hierarchy of the main dams is attempted and the role they play in the economic development of the regions they were built in is underlined. The largest dams are built on the big rivers in Asia, North America, South America and Africa. The reservoirs have multiple roles: electricity production, drinking or industrial water supply, irrigations, recreation, etc. High costs and land fragility do not allow the construction of dams in the places most affected by drought or flood. This is why they are usually built in mountainous areas, at great distance from the populated centres. On the Romanian territory, there are 246 large dams, built in the hydrographical basins of Siret, Olt, Arges, Somes, etc. The largest rivers on Earth, by discharge, (Amazon and Zair do not also include the largest dams because the landform and the type of flow have not allowed such constructions.

  20. Sustainability of dams-an evaluation approach

    Science.gov (United States)

    Petersson, E.

    2003-04-01

    Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the

  1. Thermal monitoring of leakage through Karkheh embankment dam, Iran

    Energy Technology Data Exchange (ETDEWEB)

    Mirghasemi, A.A.; Bagheri, S.M. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Civil Engineering; Heidarzadeh, M. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Civil Engineering]|[Mahab Ghodss Consulting Engineers, Tehran (Iran, Islamic Republic of)

    2007-07-01

    A newly developed and simple method for monitoring seepage in embankment dams was presented. The method of temperature measurement is based on the fact that a change in permeability results in a change in seepage flow, thereby causing a temperature change that can be readily measured in the dam body and foundation. In this study, water leaking through the Karkheh embankment dam was thermally analyzed to determine a pattern and amount of water seepage. With nearly 33 million cubic metres of fill, the Karkheh earth and rock-fill dam is the largest dam in Iran. Construction was completed in 2000. The thermal processes in the embankment were studied due to the dam's complex thermo-hydraulic behaviour. Thermal data was collected and analyzed during construction and operation of the dam. This paper presented the temperature variations for the different dam zones, including core, upstream shell, downstream shell, upstream filter, downstream filter and the plastic concrete cut-off wall. It was determined that the clay core works very well as an impermeable curtain. It was also shown that temperature variations of the Karkheh reservoir water is seasonal, and decrease as water depth increases. The reservoir water temperature remains constant beyond depths of 60 metres. The thermal behaviour of the core is not similar to that of the reservoir, indicating a very low value of seepage through the core. The pattern of temperature variations in the upstream shell in the left abutment is harmonic, while in the right abutment it is not harmonic. A harmonic pattern of temperature variation exists in some aquifers of the dam foundation, indicating high seepage through these aquifers. The Karkheh dam cut-off wall performs satisfactorily. It was determined that one dimensional equations for estimating seepage cannot be applied for the Karkheh dam. 17 refs., 11 figs.

  2. Studies Regarding the Safety in Operation of Ezer Reservoir

    Directory of Open Access Journals (Sweden)

    Balan Isabela

    2014-05-01

    Full Text Available The dam of the non-permanent reservoir Ezer, located on Jijia river is an earth dam with a maximum height of 6.18 m, which provides a global retention to the canopy of 10.330 million cubic meters. The dam founded on weak, muddy soils suffered in the years 1989 and 1992 downstream slope failures of the fillings. It was found that hydrostatic levels were high in the piezometric wells and that consolidation of the foundation soil was reduced. This paper presents a brief history of the dam and aspects regarding the behaviour monitoring of Ezer non-permanent reservoir during the years 2000-2012.

  3. The role of dams in development

    International Nuclear Information System (INIS)

    Cakmak, C.

    2001-01-01

    Although the amounts of water resources are enough for the entire world, the distribution of them in time and space shows uneven pattern. The water need is increasing with heavy industrial and agricultural requirements, while available water in the world remains as a fixed source. Economic growth, socio-cultural, and environmental developments are being realized following these changes. In order to achieve sustainable management of water resources, these changes have to be taken into consideration in water-related development projects. Demand for water is steadily increasing through out the world, even though the fresh water resources are limited and unevenly distributed, during the past three centuries, the amount of water withdrawn from fresh water resources has increased by a factor of 35, whereas world population by a factor 8. The engineering of dams, which provides regular water from reservoirs of dams to be used in case of demand pattern, is a vital part of the civilization. Dams have played a key rote in the development since the third millennium B C when the first great civilizations evolved on major rivers, such as Tigris-Euphrates, the Nile and the Indus. From these early times dams were built for flood control, water supply, irrigation and navigation. Dams also had been built to produce motive power and electricity since the industrial revolution. Development priorities changed, experience accumulated with the construction and operation of dams. Although the importance of water is well known in the human life and civilization around the world, still various groups argue that expected economic benefits are not being produced and that major environmental, economic and social costs are not being taken into account. By the end of 20th century, there were 45000 large dams in over 150 countries. According to the same classification there are 625 large dams in Turkey. All over the world, 50 % of the large dams were built mainly for irrigation. It is estimated

  4. Hydraulics of embankment-dam breaching

    Science.gov (United States)

    Walder, J. S.; Iverson, R. M.; Logan, M.; Godt, J. W.; Solovitz, S.

    2012-12-01

    Constructed or natural earthen dams can pose hazards to downstream communities. Experiments to date on earthen-dam breaching have focused on dam geometries relevant to engineering practice. We have begun experiments with dam geometries more like those of natural dams. Water was impounded behind dams constructed at the downstream end of the USGS debris-flow flume. Dams were made of compacted, well-sorted, moist beach sand (D50=0.21 mm), 3.5 m from toe to toe, but varying in height from 0.5 to 1 m; the lower the dam, the smaller the reservoir volume and the broader the initially flat crest. Breaching was started by cutting a slot 30-40 mm wide and deep in the dam crest after filling the reservoir. Water level and pore pressure within the dam were monitored. Experiments were also recorded by an array of still- and video cameras above the flume and a submerged video camera pointed at the upstream dam face. Photogrammetric software was used to create DEMs from stereo pairs, and particle-image velocimetry was used to compute the surface-velocity field from the motion of tracers scattered on the water surface. As noted by others, breaching involves formation and migration of a knickpoint (or several). Once the knickpoint reaches the upstream dam face, it takes on an arcuate form whose continued migration we determined by measuring the onset of motion of colored markers on the dam face. The arcuate feature, which can be considered the head of the "breach channel", is nearly coincident with the transition from subcritical to supercritical flow; that is, it acts as a weir that hydraulically controls reservoir emptying. Photogenic slope failures farther downstream, although the morphologically dominant process at work, play no role at all in hydraulic control aside from rare instances in which they extend upstream so far as to perturb the weir, where the flow cross section is nearly self-similar through time. The domain downstream of the critical-flow section does influence

  5. Sediment and 137Cs transport and accumulation in the Ogaki Dam of eastern Fukushima

    International Nuclear Information System (INIS)

    Yamada, Susumu; Malins, Alex; Machida, Masahiko; Kitamura, Akihiro; Kurikami, Hiroshi; Yamaguchi, Masaaki

    2015-01-01

    The Ogaki Dam Reservoir is one of the principal irrigation dam reservoirs in the Fukushima Prefecture and its upstream river basin was heavily contaminated by radioactivity from the Fukushima Daiichi Nuclear Power Plant accident. For the purpose of environmental assessment, it is important to determine the present condition of the water in the reservoir and to understand the behavior of sediment-sorbed radioactive cesium under different modes of operation of the dam, as these factors affect further contamination of arable farmlands downstream of the reservoir through sediment migration. This paper addresses this issue with numerical simulations of fluvial processes in the reservoir using the two-dimensional Nays2D code. We distinguish three grades of sediment (clay, silt, and sand), as cesium adherence depends on sediment grain size and surface area. Boundary conditions for the simulations were informed by monitoring data of the upstream catchment and by the results from a separate watershed simulation for sediment transport into the reservoir. The performance of the simulation method was checked by comparing the results for a typhoon flood in September 2013 against field monitoring data. We present results for sediment deposition on the reservoir bed and the discharge via the dam under typical yearly flood conditions, for which the bulk of annual sediment migration from the reservoir occurs. The simulations show that almost all the sand and silt that enter into the reservoir deposit onto the reservoir bed. However, the locations where they tend to deposit differ, with sand tending to deposit close to the entrance of the reservoir, whereas silt deposits throughout the reservoir. Both sand and silt settle within a few hours of entering the reservoir. In contrast, clay remains suspended in the reservoir water for a period as long as several days, thus increasing the amount that is discharged downstream from the reservoir. Under the current operating mode of the dam

  6. National Dam Inspection Program. Laurel Run Dam. NDI ID Number PA-00380. DER ID Number 35-6, Pennsylvania Gas and Water Company. Susquehanna River Basin, Laurel Run, Lackawanna County, Pennsylvania Phase I Inspection Report,

    Science.gov (United States)

    1980-04-01

    Supply. g. Design and Construction History. Laurel Run Dam was constructed in 1594 by Martin Cawley, a contractor from Archbald. The construction was...1T6Ace joly PHASE I INSPECTION REPORT -4 NATIONAL DAM INSPECTION PROGRAM Lime LAUREL RUN DAM PENNSYLVANIA GAS AND WATER COMPANY RESERVOIR AREA

  7. Construction of anhydrite dams

    Energy Technology Data Exchange (ETDEWEB)

    Bortoluzzi, L; Francois, G

    1977-05-01

    To construct a ventilation dam, the road is closed with a fibreglass sheet onto which 3 or 4 cm of anhydrite paste is sprayed. The equipment necessary is described, and the cost is compared with that of an aggregate dam.

  8. A review of the effects of dams on the hydrology, water quality and ...

    African Journals Online (AJOL)

    In this paper, the effects of dams on the hydrology, water quality and invertebrate fauna of some Nigerian inland waters were reviewed. The freshwaters considered include Awba Reservoir (Oyo State), Shiroro Lake (Kaduna State), Moro Lake (Kwara State), Aiba Reservoir (Osun State), Ikpoba Reservoir (Edo State), Onah ...

  9. Calculating earth dam seepage using HYDRUS software applications

    Directory of Open Access Journals (Sweden)

    Jakub Nieć

    2017-06-01

    Full Text Available This paper presents simulations of water seepage within and under the embankment dam of Lake Kowalskie reservoir. The aim of the study was to compare seepage calculation results obtained using analytical and numerical methods. In April 1985, after the first filling of the reservoir to normal storage levels, water leaks was observed at the base of the escarpment, on the air side of the dam. In order to control seepage flow, drainage was performed and additional piezometers installed. To explain the causes of increased pressure in the aquifer under the dam in May 1985 a simplified calculation of filtration was performed. Now, on the basis of archived data from the Department of Hydraulic and Sanitary Engineering using 3D HYDRUS STANDARD software, the conditions of seepage under the dam have been recreated and re-calculated. Piezometric pressure was investigated in three variants of drainage, including drainage before and after modernization.

  10. Sedimentation control in the reservoirs by using an obstacle

    Indian Academy of Sciences (India)

    2Faculty of Water Sciences Engineering, Shahid Chamran University, Ahwaz, Iran. 3Department of ... some experiments were carried out without an obstacle. Results showed ..... Design and management of dams, reservoirs and watersheds ...

  11. Langbjorn dam : adaptation for safe discharge of extreme floods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J. [Vattenfall Research and Development, Alvkarleby (Sweden); Ericsson, H.; Gustafsson, A. [SWECO, Stockholm (Sweden); Stenmark, M. [Vattenfall Power Consultant, Ludvika (Sweden); Mikaelsson, J. [Vattenfall Nordic Generation, Bispgarden (Sweden)

    2007-07-01

    The Langbjorn hydropower scheme, composed of an embankment dam with an impervious core of compacted moraine, a spillway section and a powerhouse, is located on the Angermanalven River in north Sweden. The scheme was commissioned in 1959 and is owned by Vattenfall. As part of its dam safety program, Vattenfall plans to adapt and refurbish many of its dams to the updated design-flood and dam-safety guidelines. Langbjorn is classified as a high hazard dam, as its updated design flood is 30 per cent higher than the existing spillway capacity. Safety evaluations were conducted for the Langbjorn dam, and, as required by the higher safety standard, there was a need to rebuild the dam, so that the design flood could be safely released without causing failure of the dam. This paper provided information on the Langbjorn hydropower scheme and discussed the planned rebuilding measures. For example, the design flood was accommodated by allowing a temporary raise of the water level by 1.3 metres above the legal retention reservoir level, which required heightening and reinforcement of the dam. Specifically, the paper discussed measures to increase the discharge capacity; handling and control of floating debris; improvement and heightening of impervious core in left and right connecting dam and abutment; measures to increase the stability of the left steep riverbank; and measures to increase stability of the spillway monoliths and the left guide wall. In addition, the paper discussed measures to ensure stability of the downstream stretch of the river bank and increase instrumentation. The paper also presented the results of hydraulic investigations to investigate the risk of erosion downstream of the dam. It was concluded that the dam could discharge the design flood and that the stability of the dam was improved and judged to be satisfactory during all foreseeable conditions. 2 refs., 8 figs.

  12. National Dam Safety Program. Lakeview Estates Dam (MO 11004), Mississippi - Kaskaskia - St. Louis Basin, Warren County, Missouri. Phase I Inspection Report.

    Science.gov (United States)

    1979-09-01

    ificatiozh Distributon/ Availabilit oe LAKEVIEW ESTATES DAM WARREN COUNTY, MISSOURI MISSOURI INVENTORY NO. 11004 PHASE I INSPECTION REPORT NATIONAL DAM SAFETY...and *impounds less than 1,000 acre-feet of water . Our inspection and evaluation indicates that the spill- way of Lakeview Estates Dam does not meet...not be measured because of high reservoir level, scalloping near the crest and a berm just under the water surface. Limestone riprap in sizes from sand

  13. Sediment trapping by dams creates methane emission hot spots

    DEFF Research Database (Denmark)

    Maeck, A.; Delsontro, T.; McGinnis, Daniel F.

    2013-01-01

    Inland waters transport and transform substantial amounts of carbon and account for similar to 18% of global methane emissions. Large reservoirs with higher areal methane release rates than natural waters contribute significantly to freshwater emissions. However, there are millions of small dams...... worldwide that receive and trap high loads of organic carbon and can therefore potentially emit significant amounts of methane to the atmosphere. We evaluated the effect of damming on methane emissions in a central European impounded river. Direct comparison of riverine and reservoir reaches, where...... sedimentation in the latter is increased due to trapping by dams, revealed that the reservoir reaches are the major source of methane emissions (similar to 0.23 mmol CH4 m(-2) d(-1) vs similar to 19.7 mmol CH4 m(-2) d(-1), respectively) and that areal emission rates far exceed previous estimates for temperate...

  14. Mechanics of slide dams

    International Nuclear Information System (INIS)

    Young, G.A.

    1970-01-01

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  15. Mechanics of slide dams

    Energy Technology Data Exchange (ETDEWEB)

    Young, G A [Engineering, Agbabian-Jacobsen Associates, Los Angeles (United States)

    1970-05-15

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  16. Cleveland Dam East Abutment : seepage control project

    Energy Technology Data Exchange (ETDEWEB)

    Huber, F.; Siu, D. [Greater Vancouver Regional District, Burnaby, BC (Canada); Ahlfield, S.; Singh, N. [Klohn Crippen Consultants Ltd., Vancouver, BC (Canada)

    2004-09-01

    North Vancouver's 91 meter high Cleveland Dam was built in the 1950s in a deep bedrock canyon to provide a reservoir for potable water to 18 municipalities. Flow in the concrete gravity dam is controlled by a gated spillway, 2 mid-level outlets and intakes and 2 low-level outlets. This paper describes the seepage control measures that were taken at the time of construction as well as the additional measures that were taken post construction to control piezometric levels, seepage and piping and slope instability in the East Abutment. At the time of construction, a till blanket was used to cover the upstream reservoir slope for 200 meters upstream of the dam. A single line grout curtain was used through the overburden from ground surface to bedrock for a distance of 166 meters from the dam to the East Abutment. Since construction, the safety of the dam has been compromised through changes in piezometric pressure, seepage and soil loss. Klohn Crippen Consultants designed a unique seepage control measure to address the instability risk. The project involved excavating 300,000 cubic meters of soil to form a stable slope and construction bench. A vertical wall was constructed to block seepage. The existing seepage control blanket was also extended by 260 meters. The social, environmental and technical issues that were encountered during the rehabilitation project are also discussed. The blanket extension construction has met design requirements and the abutment materials that are most susceptible to internal erosion have been covered by non-erodible blanket materials such as plastic and roller-compacted concrete (RCC). The project was completed on schedule and within budget and has greatly improved the long-term stability of the dam and public safety. 2 refs., 8 figs.

  17. Mathematical and field analysis of longitudinal reservoir infill

    Science.gov (United States)

    Ke, W. T.; Capart, H.

    2016-12-01

    In reservoirs, severe problems are caused by infilled sediment deposits. In long term, the sediment accumulation reduces the capacity of reservoir storage and flood control benefits. In the short term, the sediment deposits influence the intakes of water-supply and hydroelectricity generation. For the management of reservoir, it is important to understand the deposition process and then to predict the sedimentation in reservoir. To investigate the behaviors of sediment deposits, we propose a one-dimensional simplified theory derived by the Exner equation to predict the longitudinal sedimentation distribution in idealized reservoirs. The theory models the reservoir infill geomorphic actions for three scenarios: delta progradation, near-dam bottom deposition, and final infill. These yield three kinds of self-similar analytical solutions for the reservoir bed profiles, under different boundary conditions. Three analytical solutions are composed by error function, complementary error function, and imaginary error function, respectively. The theory is also computed by finite volume method to test the analytical solutions. The theoretical and numerical predictions are in good agreement with one-dimensional small-scale laboratory experiment. As the theory is simple to apply with analytical solutions and numerical computation, we propose some applications to simulate the long-profile evolution of field reservoirs and focus on the infill sediment deposit volume resulting the uplift of near-dam bottom elevation. These field reservoirs introduced here are Wushe Reservoir, Tsengwen Reservoir, Mudan Reservoir in Taiwan, Lago Dos Bocas in Puerto Rico, and Sakuma Dam in Japan.

  18. Tailings dams from the perspective of conventional dam engineering

    International Nuclear Information System (INIS)

    Szymanski, M.B.

    1999-01-01

    A guideline intended for conventional dams such as hydroelectric, water supply, flood control, or irrigation is used sometimes for evaluating the safety of a tailings dam. Differences between tailings dams and conventional dams are often substantial and, as such, should not be overlooked when applying the techniques or safety requirements of conventional dam engineering to tailings dams. Having a dam safety evaluation program developed specifically for tailings dams is essential, if only to reduce the chance of potential errors or omissions that might occur when relying on conventional dam engineering practice. This is not to deny the merits of using the Canadian Dam Safety Association Guidelines (CDSA) and similar conventional dam guidelines for evaluating the safety of tailings dams. Rather it is intended as a warning, and as a rationale underlying basic requirement of tailings dam emgineering: specific experience in tailings dams is essential when applying conventional dam engineering practice. A discussion is included that focuses on the more remarkable tailings dam safety practics. It is not addressed to a technical publications intended for such dams, or significantly different so that the use of conventional dam engineering practice would not be appropriate. The CDSA Guidelines were recently revised to include tailings dams. But incorporating tailings dams into the 1999 revision of the CDSA Guidelines is a first step only - further revision is necessary with respect to tailings dams. 11 refs., 2 tabs

  19. Flood and rockslide mitigative measures for the concrete sections of the Daisy Lake Dam

    International Nuclear Information System (INIS)

    Pataky, T.J.

    1991-01-01

    Studies conducted under British Columbia Hydro's dam safety program during the early 1980s indicated that dam sections of the Daisy Lake Dam would be overtopped by the probable maximum flood (PMF) and by a postulated slide generated wave (SGW). It was considered that the overtopping by either of the events could cause several sections of the concrete dam to fall, thereby resulting in uncontrolled release of the reservoir. The criteria used for determining foundation strength parameters, static and SGW induced water pressures, effective uplift and the appropriate factors of safety are discussed. The results of the analyses for the original dam sections and the design and implementation of the selected remedial measures are also described. These measures included lowering the Wing Dam and Saddle Dam by about 2 m to increase the spillway capacity and the installation of 43 post-tensioned anchors in the various sections of the main concrete and Wing dams. 9 refs., 8 figs., 3 tabs

  20. Development of probabilistic operating rules for Hluhluwe Dam, South Africa

    Science.gov (United States)

    Ndiritu, J.; Odiyo, J.; Makungo, R.; Mwaka, B.; Mthethwa, N.; Ntuli, C.; Andanje, A.

    2017-08-01

    Hluhluwe Dam, with a 30 million m3 reservoir that supplies water for irrigation and Hluhluwe municipality in Kwa-Zulu Natal Province, South Africa, was consistently experiencing low storage levels over several non-drought years since 2001. The dam was operated by rules of thumb and there were no records of water releases for irrigation - the main user of the dam. This paper describes an assessment of the historic behaviour of the reservoir since its completion in 1964 and the development of operating rules that accounted for: i) the multiple and different levels of reliability at which municipal and irrigation demands need to be supplied, and ii) inter-annual and inter-decadal variability of climate and inflows into the dam. The assessment of the behaviour of the reservoir was done by simulation assuming trigonometric rule curves that were optimized to maximize both yield and storage state using the SCE-UA method. The resulting reservoir behaviour matched the observed historic trajectory reasonably well and indicated that the dam has mainly been operated at a demand of 10 million m3/year until 2000 when the demand suddenly rose to 25 million m3/year. Operating rules were developed from a statistical analysis of the base yields from 500 simulations of the reservoir each using 5 year-long stochastically generated sequences of inflows, rainfall and evaporation. After the implementation of the operating rules in 2009, the storage state of the dam improved and matched those of other reservoirs in the region that had established operating rules.

  1. Flood risk management for large reservoirs

    International Nuclear Information System (INIS)

    Poupart, M.

    2006-01-01

    Floods are a major risk for dams: uncontrolled reservoir water level may cause dam overtopping, and then its failure, particularly for fill dams. Poor control of spillway discharges must be taken into consideration too, as it can increase the flood consequences downstream. In both cases, consequences on the public or on properties may be significant. Spillway design to withstand extreme floods is one response to these risks, but must be complemented by strict operating rules: hydrological forecasting, surveillance and periodic equipment controls, operating guides and the training of operators are mandatory too, in order to guarantee safe operations. (author)

  2. Feasibility of groundwater recharge dam projects in arid environments

    Science.gov (United States)

    Jaafar, H. H.

    2014-05-01

    A new method for determining feasibility and prioritizing investments for agricultural and domestic recharge dams in arid regions is developed and presented. The method is based on identifying the factors affecting the decision making process and evaluating these factors, followed by determining the indices in a GIS-aided environment. Evaluated parameters include results from field surveys and site visits, land cover and soils data, precipitation data, runoff data and modeling, number of beneficiaries, domestic irrigation demand, reservoir objectives, demography, reservoirs yield and reliability, dam structures, construction costs, and operation and maintenance costs. Results of a case study on more than eighty proposed dams indicate that assessment of reliability, annualized cost/demand satisfied and yield is crucial prior to investment decision making in arid areas. Irrigation demand is the major influencing parameter on yield and reliability of recharge dams, even when only 3 months of the demand were included. Reliability of the proposed reservoirs as related to their standardized size and net inflow was found to increase with increasing yield. High priority dams were less than 4% of the total, and less priority dams amounted to 23%, with the remaining found to be not feasible. The results of this methodology and its application has proved effective in guiding stakeholders for defining most favorable sites for preliminary and detailed design studies and commissioning.

  3. Isotope technique in JPS dam surveillance: its potential

    International Nuclear Information System (INIS)

    Sabri Hassan

    2006-01-01

    Controlling seepage is one of the most important requirements for safe dams. Any leakage at an earth embankment may be potentially dangerous since rapid internal erosion may quickly enlarge an initially minor defect. Thus dam owners need to have thorough surveillance programs that can forewarn of impending problems from seepage or other factors influencing the safety of dams. In carrying out dam surveillance works, all possible efforts should be considered and foreseeing the potential of isotope technique, JPS (Department of Irrigation and Drainage, Malaysia) and MINT (Malaysian Institute for Nuclear Technology Research) participated actively in the UNDP/RCA/IAEA program under RAS/8/093 project sponsored by the International Atomic Energy Agency (IAEA). Through these activities, it was noted that the technique demonstrated very promising potentials such as in assisting dam site selections, site investigations, watershed studies, dam and reservoir design, leakage investigations and sediments related issues, the two latter ones being relatively critical during the operational life of the dam. Establishment of baseline isotopic characteristics (or fingerprint), hydrochemistry, electrical conductivity and temperature profiles is underway for all JPS dams to be later utilized in diagnosing seepage related issues it is suggested that application of this technique be extended to other dam owners nationwide. (Author)

  4. Investigation of seepage under the Wenxiakou dam using radiotracer

    International Nuclear Information System (INIS)

    Li Zhangsu

    1988-01-01

    This paper describes the result of seepage observation on the dam foundation of Wenxiakou Reservoir using radioactive NaI (I-131) as a tracer. The main feature of the observing technique is to ascertain the seepages between the dam foundation and the clay core wall and around the abutment by measuring vertical flow. The results obtained from the observation have provided some important information for planning the engineering project of anti-seepage and reinforcement of the dam foundation and its right abutment. (author). 2 refs, 4 figs, 1 tab

  5. Investigation on the Causes of Cracking in Earth Dams (Case study: Mahmood-Abad Earth Dam

    Directory of Open Access Journals (Sweden)

    H. Rahimi

    2016-09-01

    river base beneath the dam structure. In fact , this layer has not been considered in the analysis as well in design. Because of fully saturated condition of this layer in an operation period of dam it might subjected to liquefaction during the happening of the earthquake. Evaluation of liquefaction potential of this layer based on Seed and Idriss (1971 diagram showed probability of this phenomenon. To prove this hypothesis, the stability analysis had been conducted in two different conditions by including the thin sandy layer and without considering the mentioned layer. The analysis showed in the case of absence of sandy layer the required safety factor was satisfied, but including the sandy layer leads cause the safety factor dropped to 0.84 that means accruing of liquefaction in the thin layer would lead to structural instability of the studied dam. The simulation of the behavior of dam by employing the accrued earthquake acceleration confirmed the liquefaction has been accrued in the thin sandy layer. The results of finite element simulation showed the depth of the cracks on the crest is about 2 meters and also the upstream slope has slipped about 81 mm to the reservoir of the dam. These results was consistent with the observed values. To overcome the next risks, also to repair the damaged parts of the dam, 3 different methods had been proposed. The curing technics was deploying of the reservoir and removing of the damage part of the dam and as well the thin sandy layer and reconstructed that part of dam, Deploying of reservoir of the dam and adjusting the slope of the upper shoulder to stable condition and at least repairing the developed cracks by injecting cement slurry and tolerate the current condition without imposition any additional costs to the project. The third method has been selected, but for any probable risky condition monitoring of the dam has been advised. Conclusion: Based on the overall results of the investigations, it was concluded that cracking

  6. Public safety around dams

    Energy Technology Data Exchange (ETDEWEB)

    Bourassa, H [Centre d' expertise hydrique du Quebec, Quebec, PQ (Canada)

    2009-07-01

    Fourty public dams are managed on a real-time basis by the Centre d'expertise hydrique du Quebec (CEHQ). This presentation described the public dams owned by the CEHQ and discussed the public safety measures at the dams. The dams serve various purposes, including protection against floods; industrial or drinking water supply; resort or recreational activities; hydroelectric development; and wildlife conservation. Trigger events were also discussed, such as the complaint at Rapides-des-Cedres dam and deaths that occurred in 2004 when water from a dam was released without warning. Several photographs were presented to illustrate that people were unaware of the danger. Initiatives aimed at raising awareness and studying public safety issues were discussed. A pilot project was launched and a permanent committee was created to evaluate all aspects of public safety at the dams owned by CEHQ. The first tasks of the committee were to establish requirements for waterway safety barriers, both upstream and downstream, for all public dams; to establish requirements for safety signage for all public dams; and to develop criteria to decide on safety signage at each dam. figs.

  7. Public safety around dams

    Energy Technology Data Exchange (ETDEWEB)

    Bourassa, H. [Centre d' expertise hydrique du Quebec, Quebec, PQ (Canada)

    2009-07-01

    Fourty public dams are managed on a real-time basis by the Centre d'expertise hydrique du Quebec (CEHQ). This presentation described the public dams owned by the CEHQ and discussed the public safety measures at the dams. The dams serve various purposes, including protection against floods; industrial or drinking water supply; resort or recreational activities; hydroelectric development; and wildlife conservation. Trigger events were also discussed, such as the complaint at Rapides-des-Cedres dam and deaths that occurred in 2004 when water from a dam was released without warning. Several photographs were presented to illustrate that people were unaware of the danger. Initiatives aimed at raising awareness and studying public safety issues were discussed. A pilot project was launched and a permanent committee was created to evaluate all aspects of public safety at the dams owned by CEHQ. The first tasks of the committee were to establish requirements for waterway safety barriers, both upstream and downstream, for all public dams; to establish requirements for safety signage for all public dams; and to develop criteria to decide on safety signage at each dam. figs.

  8. Ice interactions at a dam face

    Energy Technology Data Exchange (ETDEWEB)

    Morse, B.; Morse, J.; Beaulieu, P.; Pratt, Y. [Laval Univ., Quebec City, PQ (Canada). Dept. of Civil Engineering; Stander, E. [State Univ. of New York, Cobleskill College, Cobleskill, NY (United States). Dept. of Natural Sciences; Cote, A.; Tarras, A.; Noel, P. [Hydro-Quebec, Varennes, PQ (Canada). IREQ

    2009-07-01

    This paper reported on a joint research project between Laval University and Hydro-Quebec to study ice forces on dams in an effort to harmonize design criteria and develop mitigation strategies. This paper introduced the project and explored some of the preliminary results of the 2007-2008 field season. Ice displacement, ice stresses and ice forces on the LaGabelle dam were measured at several locations. The paper identified and discussed the complex relationships between data sets and discussed the spatial-temporal variability of the ice forces and its impact on design criteria. The project objective was to develop design criteria for ice forces on dams and to provide a scientific basis for interpreting and harmonizing existing recommended criteria. The methodology and site description were presented. It was concluded that the ice processes in a reservoir near a dam face subject to water fluctuations are quite complex. Therefore, in order to know the real average pressure on the dam, a significant amount of panels are required, having important implications for determining safe design values. 9 refs., 10 figs.

  9. Grouting of karstic arch dam foundation

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.; Rigbey, S. [Acres International, Niagara Falls, ON (Canada)

    2002-07-01

    A 200 m high arch dam and a 2000 MW underground power house complex is under development in the Middle East. The project is located in a highly seismic area in rugged, mountainous terrain. The arch dam is constructed on good quality limestone and dolomitic limestone rock mass, but it contains several zones of disturbed or sheared rock. The basement rock is slightly karstic with hydraulic conductivities in the order of 100 Lugeons. In order to get a satisfactory foundation surface for the dam, it will be necessary to excavate extensively and backfill with concrete. Because of the presence of many clay infilled cavities and fractures, geotechnicians are considering the installation of a multiple row grout curtain to a depth of 150 m below the dam foundation to ensure adequate seepage and uplift parameters when the reservoir is impounded. Initial grouting water pressure test results suggested that the grouting and drainage curtain should be extended to the left abutment beyond the current design. However, when horizontal slide models of the dam abutment were developed using the finite element program SEEPW, it was shown that there is no benefit to extending the length of grout curtains unless they are tied to an area of much lower hydraulic conductivity much deeper in the abutment. 1 tab., 5 figs.

  10. 76 FR 60732 - Drawbridge Operation Regulations; Navesink (Swimming) River, NJ

    Science.gov (United States)

    2011-09-30

    ... Operation Regulations; Navesink (Swimming) River, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... (Swimming) River between Oceanic and Locust Point, New Jersey. The deviation is necessary to facilitate...: The Oceanic Bridge, across the Navesink (Swimming) River, mile 4.5, between Oceanic and Locust Point...

  11. 78 FR 77591 - Drawbridge Operation Regulation; Shark River, NJ

    Science.gov (United States)

    2013-12-24

    ... Operation Regulation; Shark River, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from drawbridge... governs the bascule span of the Route 71 Bridge across Shark River (South Channel), mile 0.8, at Belmar... motor seals and instrumentation on the bridge. The Route 71 Bridge across Shark River (South Channel...

  12. 75 FR 13681 - Television Broadcasting Services; Atlantic City, NJ

    Science.gov (United States)

    2010-03-23

    ...] Television Broadcasting Services; Atlantic City, NJ AGENCY: Federal Communications Commission. ACTION: Final... not less than one very high frequency commercial television channel to each State, if technically... Review Act, see 5 U.S.C. 801(a)(1)(A). List of Subjects in 47 CFR Part 73 Television, Television...

  13. Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River

    Science.gov (United States)

    Skalak, Katherine; Benthem, Adam J.; Schenk, Edward R.; Hupp, Cliff R.; Galloway, Joel M.; Nustad, Rochelle A.; Wiche, Gregg J.

    2013-01-01

    The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries, and habitat. Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Though the effects of dams and reservoirs are well-documented, their impacts have been studied individually, with relatively little attention paid to their interaction along a river corridor. We examine the morphological and sedimentological changes in the Upper Missouri River between the Garrison Dam in ND (operational in 1953) and Oahe Dam in SD (operational in 1959). Through historical aerial photography, stream gage data, and cross sectional surveys, we demonstrate that the influence of the upstream dam is still a major control of river dynamics when the backwater effects of the downstream reservoir begin. In the “Anthropocene”, dams are ubiquitous on large rivers and often occur in series, similar to the Garrison Dam Segment. We propose a conceptual model of how interacting dams might affect river geomorphology, resulting in distinct and recognizable morphologic sequences that we term “Inter-Dam sequence” characteristic of major rivers in the US.

  14. Hydrogeophysical investigations at Hidden Dam, Raymond, California

    Science.gov (United States)

    Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

    2011-01-01

    Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, as well as the self-potential response using petrophysical relationships and electrokinetic coupling equations.The self-potential survey consists of 512 measurements on the downstream area of the dam, and corroborates known seepage areas on the northwest side of the dam. Two direct-current resistivity profiles, each approximately 2,500 ft (762 m) long, indicate a broad sediment channel under the northwest side of the dam, which may be a significant seepage pathway through the foundation. A focusing of seepage in low-topography areas downstream of the dam is confirmed from the numerical flow simulations, which is also consistent with past observations. Little evidence of seepage is identified from the self-potential data on the southeast side of the dam, also consistent with historical records, though one possible area of focused seepage is identified near the outlet works. Integration of the geophysical surveys, numerical modeling, and observation well data provides a framework for better understanding seepage at the site through a combined hydrogeophysical approach.

  15. Spruce Lake Dam reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, G. [SGE Acres Ltd., Fredericton, NB (Canada); Barnard, J. [SGE Acres Ltd., St. John' s, NF (Canada); Vriezen, C. [City of Saint John, NF (Canada); Stephenson, M. [Jacques Whitford Environment Ltd., Fredericton, NB (Canada)

    2004-09-01

    Spruce Lake Dam was constructed in 1898 as part of the water supply system for Saint John, New Brunswick. The original dam was a 6 meter high, 140 meter long concrete gravity dam with an intake structure at its mid point and an overflow spillway at the left abutment. A rehabilitation project was launched in 2001 to bring the deteriorated dam into conformance with the dam safety guidelines of the Canadian Dam Association. The project criteria included minimal disruption to normal operation of water supply facilities and no negative effect on water quality. The project involved installation of a new low level outlet, removal of a gate house and water intake pipes, replacement of an access road culvert in the spillway channel, and raising the earth dam section by 1.8 meters to allow for increased water storage. The new raised section has an impervious core. The project also involved site and geotechnical investigations as well as hydrotechnical and environmental studies. This presentation described the final design of the remedial work and the environmental permitting procedures. Raising the operating level of the system proved successful as demonstrated by the fewer number of pumping days required after dam rehabilitation. The dam safety assessment under the Canadian Environmental Assessment Act began in April 2001, and the rehabilitation was completed by the end of 2002. 1 tab., 8 figs.

  16. a rapid health impact assessment of the university of ilorin dam

    African Journals Online (AJOL)

    Many Dams have been constructed in different parts of the world and for different purposes. While these dams have in most cases served the reason for their construction, the resultant environmental impact have been a subject of concern. The creation of a reservoir not only changes the ecology and hydrology of the ...

  17. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neural reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers, geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  18. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  19. 76 FR 53045 - Prevailing Rate Systems; Abolishment of Monmouth, NJ, as a Nonappropriated Fund Federal Wage...

    Science.gov (United States)

    2011-08-25

    ... Monmouth, NJ, as a Nonappropriated Fund Federal Wage System Wage Area AGENCY: U.S. Office of Personnel... Wage System (FWS) wage area and redefine Monmouth County, NJ, to the Burlington, NJ, NAF wage area. These changes are necessary because the closure of Fort Monmouth will leave the Monmouth wage area...

  20. 77 FR 11383 - Prevailing Rate Systems; Abolishment of Monmouth, NJ, as a Nonappropriated Fund Federal Wage...

    Science.gov (United States)

    2012-02-27

    ... Monmouth, NJ, as a Nonappropriated Fund Federal Wage System Wage Area AGENCY: U.S. Office of Personnel... abolish the Monmouth, New Jersey, nonappropriated fund (NAF) Federal Wage System (FWS) wage area and redefine Monmouth County, NJ, to the Burlington, NJ, NAF wage area. These changes are necessary because the...

  1. 78 FR 28139 - Drawbridge Operation Regulation; Tuckahoe River, Between Corbin City and Upper Township, NJ

    Science.gov (United States)

    2013-05-14

    ... Operation Regulation; Tuckahoe River, Between Corbin City and Upper Township, NJ AGENCY: Coast Guard, DHS... River, mile 8.0, between Corbin City and Upper Township, NJ. The deviation is necessary to facilitate... operating schedule, the State Highway Bridge, mile 8.0, between Corbin City and Upper Township, NJ shall...

  2. Phase I Inspection Report. National Dam Safety Program. Round Valley South Dam, Hunterdon County, New Jersey.

    Science.gov (United States)

    1978-05-01

    defined by the Recommended Guidelines for Safety Inspection of Dams. .M • wwM •^^^nmifgnmmmm’m •PH J.I.I MPU C. Hazard Classification - The...Conservation and Economic Development, August 1958. 3) Contract RV-1, State of New Jersey Department of Conservation and Economic Development...FIGURE 4 iymmmmr STATE OF NEW JERSEY DEPARTMENT OF CONSERVATION AND ECONOMIC DEVFl OtVNKM OF WATNt FOUCY «MO mm 1 ROUND VALLEY RESERVOIR

  3. Rescuing the nonjet (NJ azimuth quadrupole from the flow narrative

    Directory of Open Access Journals (Sweden)

    Trainor Thomas A.

    2017-01-01

    Full Text Available According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity υ2 and interpreted to represent elliptic flow. Jet angular correlations may also contribute to υ2 data “nonflow” depending on the method used to calculate υ2, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modication (“jet quenching” in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential υ2(pt data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole spectra indicate a common boosted hadron source for a small minority of hadrons that “carry” the NJ quadrupole structure, that the narrow source-boost distribution is characteristic of an expanding thin cylindrical shell (strongly contradicting hydro descriptions, and that in the boost frame a single universal quadrupole spectrum (Lévy distribution on transverse mass mt accurately describes data for several hadron species scaled according to their statistical-model abundances. The quadrupole spectrum shape changes very little from RHIC to LHC energies. Taken in combination those characteristics strongly suggest a unique nonflow (and nonjet QCD mechanism for the NJ quadrupole conventionally represented by υ2.

  4. Rescuing the nonjet (NJ) azimuth quadrupole from the flow narrative

    Science.gov (United States)

    Trainor, Thomas A.

    2017-04-01

    According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity υ2 and interpreted to represent elliptic flow. Jet angular correlations may also contribute to υ2 data "nonflow" depending on the method used to calculate υ2, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ) quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modication ("jet quenching") in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential υ2(pt) data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole spectra indicate a common boosted hadron source for a small minority of hadrons that "carry" the NJ quadrupole structure, that the narrow source-boost distribution is characteristic of an expanding thin cylindrical shell (strongly contradicting hydro descriptions), and that in the boost frame a single universal quadrupole spectrum (Lévy distribution) on transverse mass mt accurately describes data for several hadron species scaled according to their statistical-model abundances. The quadrupole spectrum shape changes very little from RHIC to LHC energies. Taken in combination those characteristics strongly suggest a unique nonflow (and nonjet) QCD mechanism for the NJ quadrupole conventionally represented by υ2.

  5. A Framework for Multifunctional Green Infrastructure Investment in Camden, NJ

    OpenAIRE

    Kate Zidar; Maryse Belliveau-Nance; Anthony Cucchi; Danielle Denk; Andrew Kricun; Shaun O’Rourke; Shudipto Rahman; Sri Rangarajan; Eric Rothstein; Justin Shih; Franco Montalto

    2017-01-01

    This study demonstrates a decision-support framework for planning Green Infrastructure (GI) systems that maximize urban ecosystem services in Camden, NJ. Seven key ecosystem services are evaluated (urban agriculture expansion, combined sewer overflow reduction, heat island reduction, flooding reduction, capacity building/green jobs expansion, fitness expansion, and stress reduction), to produce a normalized value for each service for each drainage sub-basin within the city. Gaps in ecosystem ...

  6. Occurrence of cyanobacteria genera in the Vaal Dam: implications ...

    African Journals Online (AJOL)

    The occurrence of cyanobacteria genera in the Vaal Dam was analysed and the factors that influence its dominance in the particular reservoir were also investigated. The study was motivated by the effects of the secondary metabolites of cyanobacteria genera on potable water production. Cyanobacteria genera have been ...

  7. Stability of earth dam with a vertical core

    Directory of Open Access Journals (Sweden)

    Orekhov Vyacheslav Valentinovich

    2016-01-01

    Full Text Available Earth dam with impervious element in the form of asphaltic concrete core is currently the most promising type of earth dams (due to simple construction technology and universal service properties of asphaltic concrete and is widely used in the world. However, experience in the construction and operation of high dams (above 160 m is not available, and their work is scarcely explored. In this regard, the paper discusses the results of computational prediction of the stress-strain state and stability of a high earth dam (256 m high with the core. The authors considered asphaltic concrete containing 7 % of bitumen as the material of the core. Gravel was considered as the material of resistant prisms. Design characteristics of the rolled asphaltic concrete and gravel were obtained from the processing of the results of triaxial tests. The calculations were performed using finite element method in elastoplastic formulation and basing on the phased construction of the dam and reservoir filling. The research shows, that the work of embankment dam with vertical core during filling of the reservoir is characterized by horizontal displacement of the lower resistant prism in the tailrace and the formation of a hard wedge prism descending along the core in the upper resistant prism. The key issue of the safety assessment is to determine the safety factor of the overall stability of the dam, for calculation of which the destruction of the earth dam is necessary, which can be done by reducing the strength properties of the dam materials. As a results of the calculations, the destruction of the dam occurs with a decrease in the strength characteristics of the materials of the dam by 2.5 times. The dam stability depends on the stability of the lower resistant prism. The destruction of its slope occurs on the classical circular-cylindrical surface. The presence of a potential collapse surface in the upper resistant prism (on the edges of the descending wedge does

  8. Deriving Area-storage Curves of Global Reservoirs

    Science.gov (United States)

    Mu, M.; Tang, Q.

    2017-12-01

    Basic information including capacity, dam height, and largest water area on global reservoirs and dams is well documented in databases such as GRanD (Global Reservoirs and Dams), ICOLD (International Commission on Large Dams). However, though playing a critical role in estimating reservoir storage variations from remote sensing or hydrological models, area-storage (or elevation-storage) curves of reservoirs are not publicly shared. In this paper, we combine Landsat surface water extent, 1 arc-minute global relief model (ETOPO1) and GRanD database to derive area-storage curves of global reservoirs whose area is larger than 1 km2 (6,000 more reservoirs are included). First, the coverage polygon of each reservoir in GRanD is extended to where water was detected by Landsat during 1985-2015. Second, elevation of each pixel in the reservoir is extracted from resampled 30-meter ETOPO1, and then relative depth and frequency of each depth value is calculated. Third, cumulative storage is calculated with increasing water area by every one percent of reservoir coverage area and then the uncalibrated area-storage curve is obtained. Finally, the area-storage curve is linearly calibrated by the ratio of calculated capacity over reported capacity in GRanD. The derived curves are compared with in-situ reservoir data collected in Great Plains Region in US, and the results show that in-situ records are well captured by the derived curves even in relative small reservoirs (several square kilometers). The new derived area-storage curves have the potential to be employed in global monitoring or modelling of reservoirs storage and area variations.

  9. Dam safety operating guidelines

    International Nuclear Information System (INIS)

    Elsayed, E.; Leung, T.; Kirkham, A.; Lum, D.

    1990-01-01

    As part of Ontario Hydro's dam structure assessment program, the hydraulic design review of several river systems has revealed that many existing dam sites, under current operating procedures, would not have sufficient discharge capacity to pass the Inflow Design Flood (IDF) without compromising the integrity of the associated structures. Typical mitigative measures usually considered in dealing with these dam sites include structural alterations, emergency action plans and/or special operating procedures designed for extreme floods. A pilot study was carried out for the Madawaska River system in eastern Ontario, which has seven Ontario Hydro dam sites in series, to develop and evaluate the effectiveness of the Dam Safety Operating Guidelines (DSOG). The DSOG consist of two components: the flood routing schedules and the minimum discharge schedules, the former of which would apply in the case of severe spring flood conditions when the maximum observed snowpack water content and the forecast rainfall depth exceed threshold values. The flood routing schedules would identify to the operator the optimal timing and/or extent of utilizing the discharge facilities at each dam site to minimize the potential for dam failures cased by overtopping anywhere in the system. It was found that the DSOG reduced the number of structures overtopped during probable maximum flood from thirteen to four, while the number of structures that could fail would be reduced from seven to two. 8 refs., 4 figs., 3 tabs

  10. Geomorphic responses to dam removal in the United States – a two-decade perspective

    Science.gov (United States)

    Major, Jon J.; East, Amy; O'Connor, Jim E.; Grant, Gordon E.; Wilcox, Andrew C.; Magirl, Christopher S.; Collins, Matthias J.; Tullos, Desiree D.; Tsutsumi, Daizo; Laronne, Jonathan B.

    2017-01-01

    Recent decades have seen a marked increase in the number of dams removed in the United States. Investigations following a number of removals are beginning to inform how, and how fast, rivers and their ecosystems respond to released sediment. Though only a few tens of studies detail physical responses to removals, common findings have begun to emerge. They include: (1) Rivers are resilient and respond quickly to dam removals, especially when removals are sudden rather than prolonged. Rivers can swiftly evacuate large fractions of reservoir sediment (≥50% within one year), especially when sediment is coarse grained (sand and gravel). The channel downstream typically takes months to years—not decades—to achieve a degree of stability within its range of natural variability. (2) Modest streamflows (<2-year return interval flows) can erode and transport large amounts of reservoir sediment. Greater streamflows commonly are needed to access remnant reservoir sediment and transport it downstream. (3) Dam height, sediment volume, and sediment caliber strongly influence downstream response to dam removal. Removals of large dams (≥10 m tall) have had longer-lasting and more widespread downstream effects than more common removals of small dams. (4) Downstream valley morphology and position of a dam within a watershed influence the distribution of released sediment. Valley confinement, downstream channel gradient, locations and depths of channel pools, locations and geometries of extant channel bars, and locations of other reservoirs all influence the downstream fate of released sediment.

  11. Greenhouse Gas Emissions from Hydroelectric Reservoirs in Tropical Regions

    International Nuclear Information System (INIS)

    Pinguelli Rosa, L.; Aurelio dos Santos, M.; Oliveira dos Santos, E.; Matvienko, B.; Sikar, E.

    2004-01-01

    This paper discusses emissions by power-dams in the tropics. Greenhouse gas emissions from tropical power-dams are produced underwater through biomass decomposition by bacteria. The gases produced in these dams are mainly nitrogen, carbon dioxide and methane. A methodology was established for measuring greenhouse gases emitted by various power-dams in Brazil. Experimental measurements of gas emissions by dams were made to determine accurately their emissions of methane (CH4) and carbon dioxide (CO2) gases through bubbles formed on the lake bottom by decomposing organic matter, as well as rising up the lake gradient by molecular diffusion. The main source of gas in power-dams reservoirs is the bacterial decomposition (aerobic and anaerobic) of autochthonous and allochthonous organic matter that basically produces CO2 and CH4. The types and modes of gas production and release in the tropics are reviewed

  12. Qu'Appelle River Dam, dam break analysis using advanced GIS tools for rapid modelling and inundation mapping

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, D. [Hatch Energy, Winnipeg, MB (Canada); Campbell, C. [Saskatchewan Watershed Authority, Moose Jaw, SK (Canada); Groeneveld, J. [Hatch Energy, Calgary, AB (Canada)

    2008-07-01

    The South Saskatchewan River Project (SSRP) comprises a multi-purpose reservoir that provides water for conservation and irrigation, flood control, power generation, recreation, and municipal and industrial water supply. In addition to the 64 m high Gardiner Dam, the 27 m high Qu'Appelle River Dam and the 22 km long Lake Diefenbaker Reservoir, the SSRP also includes ancillary works. The Qu'Appelle River valley extends for 458 km before connecting to the Assiniboine River. The valley is incised up to 90 m in depth and is a popular cottaging and recreational area with several major communities located in the flood plain. In the event of a breach of the Qu'Appelle Dam, the discharge will increase from a normal maximum discharge of under 60 m{sup 3} per second to over 50,000 m{sup 3} per second. The Saskatchewan Watershed Authority (SWA) is responsible for ensuring safe development of the Province's water resources, without affecting reservoir or lake operations, and preventing damage from flooding, erosion or land slides. It is in the process of developing Hazard Assessments and emergency preparedness plans for each of their dams in accordance with the Canadian Dam Safety Guidelines. Studies using GIS technology and the hydrodynamic routing model HEC-RAS have been completed to evaluate the potential inundation that may result in the event of failure of the Qu'Appelle River Dam. These studies involved the development of a breach parameter model using a breach data set revised to better reflect the Qu'Appelle River Dam; the development of a dam break model for the Qu'Appelle River Dam and downstream river and flood plain; and, the use of this model to simulate two potential dam failure scenarios for the Qu'Appelle River Dam, notably failure during passage of the PMF and failure during fair weather conditions. Inundation maps have been prepared for the downstream Qu'Appelle River valley for each of the above events. 3 refs., 4

  13. Detection of water leaks in the dam Joumine and study of sedimentation in the dam Ghezela by nuclear method

    International Nuclear Information System (INIS)

    Sari Souha

    2013-01-01

    The objective of this study is to determinate the paths of leaks observed in the dam Joumine and to identify the origin of salinity in the drain D2. In addition, the evaluation of the sedimentation measurement of suspended elements in the dam Ghezela is our second objective. The Joumine dam located in the North-east of Tunisia (governorate of Bizerte), was built in 1983 has an upstream watershed area of 418 km 2 . The reservoir capacity is 130 Mm 3 . This dam observed a water leakage from its implementation at the two drains D1 and D2 with a emerging flow rate reached a value close to 500 l/s, about 16 pour cent of its capacity. The injection of an insulating material in Karsts networks reduces the leakage rate to a value of 120 l / s in 1993 and 88 l / s in 2013, but this decrease was accompanied by an increase in salinity level in D2. The results from a multidisciplinary approach showed that the leakage path from the left bank of the reservoir where the leak was first detected, heading both D1 and D2 drains and the salinity in drain D2 due to the dissolution of the gypsum layer downstream of the dam and the contribution of brackish water from the left bank. The Ghezela dam located in the same area, was built in 1984 has an upstream watershed area of 48 km 2 . This dam has been an increase in sedimentation of 0.3 million m3 in 1994 to 1.7 million m 3 in 2010. In this study, the suspended elements were measured with a nuclear probe composed by a radioactive source of americium 241 and a NaI detector trained by a boat at different depth in the reservoir.

  14. Sudden water pollution accidents and reservoir emergency operations: impact analysis at Danjiangkou Reservoir.

    Science.gov (United States)

    Zheng, Hezhen; Lei, Xiaohui; Shang, Yizi; Duan, Yang; Kong, Lingzhong; Jiang, Yunzhong; Wang, Hao

    2018-03-01

    Danjiangkou Reservoir is the source reservoir of the Middle Route of the South-to-North Water Diversion Project (MRP). Any sudden water pollution accident in the reservoir would threaten the water supply of the MRP. We established a 3-D hydrodynamic and water quality model for the Danjiangkou Reservoir, and proposed scientific suggestions on the prevention and emergency management for sudden water pollution accidents based on simulated results. Simulations were performed on 20 hypothetical pollutant discharge locations and 3 assumed amounts, in order to model the effect of pollutant spreading under different reservoir operation types. The results showed that both the location and mass of pollution affected water quality; however, different reservoir operation types had little effect. Five joint regulation scenarios, which altered the hydrodynamic processes of water conveyance for the Danjiangkou and Taocha dams, were considered for controlling pollution dispersion. The results showed that the spread of a pollutant could be effectively controlled through the joint regulation of the two dams and that the collaborative operation of the Danjiangkou and Taocha dams is critical for ensuring the security of water quality along the MRP.

  15. Thermal effects of dams in the Willamette River basin, Oregon

    Science.gov (United States)

    Rounds, Stewart A.

    2010-01-01

    Methods were developed to assess the effects of dams on streamflow and water temperature in the Willamette River and its major tributaries. These methods were used to estimate the flows and temperatures that would occur at 14 dam sites in the absence of upstream dams, and river models were applied to simulate downstream flows and temperatures under a no-dams scenario. The dams selected for this study include 13 dams built and operated by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Project, and 1 dam on the Clackamas River owned and operated by Portland General Electric (PGE). Streamflows in the absence of upstream dams for 2001-02 were estimated for USACE sites on the basis of measured releases, changes in reservoir storage, a correction for evaporative losses, and an accounting of flow effects from upstream dams. For the PGE dam, no-project streamflows were derived from a previous modeling effort that was part of a dam-relicensing process. Without-dam streamflows were characterized by higher peak flows in winter and spring and much lower flows in late summer, as compared to with-dam measured flows. Without-dam water temperatures were estimated from measured temperatures upstream of the reservoirs (the USACE sites) or derived from no-project model results (the PGE site). When using upstream data to estimate without-dam temperatures at dam sites, a typical downstream warming rate based on historical data and downstream river models was applied over the distance from the measurement point to the dam site, but only for conditions when the temperature data indicated that warming might be expected. Regressions with measured temperatures from nearby or similar sites were used to extend the without-dam temperature estimates to the entire 2001-02 time period. Without-dam temperature estimates were characterized by a more natural seasonal pattern, with a maximum in July or August, in contrast to the measured patterns at many of the tall dam sites

  16. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  17. Massive accumulation of highly polluted sedimentary deposits by river damming

    Energy Technology Data Exchange (ETDEWEB)

    Palanques, Albert, E-mail: albertp@icm.csic.es [Institute of Marine Sciences (CSIC), Passeig Maritim de la Barceloneta, 37-49, Barcelona 08003 (Spain); Grimalt, Joan [Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona, 18, Barcelona 08034 (Spain); Belzunces, Marc; Estrada, Ferran; Puig, Pere; Guillén, Jorge [Institute of Marine Sciences (CSIC), Passeig Maritim de la Barceloneta, 37-49, Barcelona 08003 (Spain)

    2014-11-01

    Uncontrolled dumping of anthropogenic waste in rivers regulated by dams has created contaminated deposits in reservoirs that have remained unidentified for decades. The Flix Reservoir is located in the Ebro River, the second largest river flowing into the NW Mediterranean, has been affected by residue dumping from a chlor-alkali electrochemical plant for decades. High-resolution seismic profiles, bathymetric data, surficial sediment samples and sediment cores were obtained in the Flix Reservoir to study the characteristics of the deposit accumulated by this dumping. These data were used to reconstruct the waste deposit history. Since the construction of the Flix Dam in 1948, more than 3.6 × 10{sup 5} t of industrial waste has accumulated in the reservoir generating a delta-like deposit formed by three sediment lobes of fine-grained material highly contaminated by Hg, Cd, Zn and Cr (max: 640, 26, 420 and 750 mg kg{sup −1}, respectively). This contamination was associated with the Hg that was used for the cathode in the electrochemical plant from 1949 and with the production of phosphorite derivatives from 1973. After the construction of two large dams only a few kilometres upstream during the 1960s, the solids discharged from the industrial complex became the main sediment source to the Flix Reservoir. The deposit has remained in the reservoir forming a delta that obstructs about 50% of the river water section. Its stability only depended on the flow retention by the Flix Dam. At present, this contaminated waste deposit is being removed from the water reservoir as it is a cause of concern for the environment and for human health downriver. - Highlights: • A delta-like anthropogenic deposit prograded into the reservoir behind the Flix dam. • More than 3.6 × 10{sup 5} t of anthropogenic waste was accumulated in less than 4 decades. • A waste deposit with extreme levels of Hg and Cd was trapped in the Flix Reservoir. • The main pollution was related to

  18. Teton Dam failure

    Energy Technology Data Exchange (ETDEWEB)

    Snorteland, N. [United States Dept. of the Interior, Washington, DC (United States). Bureau of Reclamation

    2009-07-01

    This case summary discussed an internal erosion failure that occurred at the embankment foundation of Teton Dam. The project was designed as a run-of-the-river power generation facility and to provide irrigation, flood protection, and power generation to the lower Teton region of southern Idaho. The dam site was located next to the eastern Snake River plain, a volcanic filled depression. The foundation's cutoff trench was excavated into the bedrock along the length of the dam. The dam was designed as a zoned earthfill with a height of 305 feet. A trench made of low plasticity windblown silt was designed to connect the embankment core to the rock foundation. Seeps were noted in 1976, and a leak was observed near the toe of the dam. A wet spot appeared on the downstream face of the dam at elevation 5200. A sinkhole then developed. The embankment crest collapsed, and the dam breached. Peak outflow was estimated at 1,000,000 cfs. The failure was attributed to a lack of communication between designers, a failure to understand geologic information about the region, and an insufficient review of designs and specifications by designers and field personnel. No monitoring instrumentation was installed in the embankment. Approximately 300 square miles were inundated, and 25,000 people were displaced. Eleven people were killed. A review group noted that the rock surface was not adequately sealed, and that the dam failed as a result of inadequate protection of the impervious core material from internal erosion. 42 figs.

  19. Matahina Dam : lessons learned from an earthquake-related internal erosion incident at the Matahina Dam, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Gillon, M. [Damwatch Services Ltd., Wellington (New Zealand)

    2009-07-01

    This case history discussed internal erosion damage and crest subsidence caused by an earthquake at the Matahina Dam in New Zealand. The study showed that cracking and internal erosion was initiated during the 1967 reservoir filling operation. Located in an area of active volcanism and faulting, the dam is located on a river with extensive erosion through an ignimbrite flow. The dam's core is founded on compact Tertiary age sediments overlain by sand and gravel deposits beneath the shoulders of the dam. The earthquake caused a rupture along an unidentified fault trace 12 km from the dam. The horizontal base acceleration recorded at the dam was 3.25 m/s. Transverse cracking was observed at each abutment, and deformations were observed in the rockfill. An investigation program was conducted to determine the dam's integrity. Piezometer measurements showed widespread fluctuations. It was concluded that the lack of an effective filter was a significant design omission. 12 refs., 12 figs.

  20. Turbid releases from Glen Canyon Dam, Arizona, following rainfall-runoff events of September 2013

    Science.gov (United States)

    Wildman, Richard A.; Vernieu, William

    2017-01-01

    Glen Canyon Dam is a large dam on the Colorado River in Arizona. In September 2013, it released turbid water following intense thunderstorms in the surrounding area. Turbidity was >15 nephelometric turbidity units (NTU) for multiple days and >30 NTU at its peak. These unprecedented turbid releases impaired downstream fishing activity and motivated a rapid-response field excursion. At 5 locations upstream from the dam, temperature, specific conductance, dissolved oxygen, chlorophyll a, and turbidity were measured in vertical profiles. Local streamflow and rainfall records were retrieved, and turbidity and specific conductance data in dam releases were evaluated. Profiling was conducted to determine possible sources of turbidity from 3 tributaries nearest the dam, Navajo, Antelope, and Wahweap creeks, which entered Lake Powell as interflows during this study. We discuss 4 key conditions that must have been met for tributaries to influence turbidity of dam releases: tributary flows must have reached the dam, tributary flows must have been laden with sediment, inflow currents must have been near the depth of dam withdrawals, and the settling velocity of particles must have been slow. We isolate 2 key uncertainties that reservoir managers should resolve in future similar studies: the reach of tributary water into the reservoir thalweg and the distribution of particle size of suspended sediment. These uncertainties leave the source of the turbidity ambiguous, although an important role for Wahweap Creek is possible. The unique combination of limnological factors we describe implies that turbid releases at Glen Canyon Dam will continue to be rare.

  1. Earthquake Hazard for Aswan High Dam Area

    Science.gov (United States)

    Ismail, Awad

    2016-04-01

    Earthquake activity and seismic hazard analysis are important components of the seismic aspects for very essential structures such as major dams. The Aswan High Dam (AHD) created the second man-made reservoir in the world (Lake Nasser) and is constructed near urban areas pose a high-risk potential for downstream life and property. The Dam area is one of the seismically active regions in Egypt and is occupied with several cross faults, which are dominant in the east-west and north-south. Epicenters were found to cluster around active faults in the northern part of Lake and AHD location. The space-time distribution and the relation of the seismicity with the lake water level fluctuations were studied. The Aswan seismicity separates into shallow and deep seismic zones, between 0 and 14 and 14 and 30 km, respectively. These two seismic zones behave differently over time, as indicated by the seismicity rate, lateral extent, b-value, and spatial clustering. It is characterized by earthquake swarm sequences showing activation of the clustering-events over time and space. The effect of the North African drought (1982 to present) is clearly seen in the reservoir water level. As it decreased and left the most active fault segments uncovered, the shallow activity was found to be more sensitive to rapid discharging than to the filling. This study indicates that geology, topography, lineations in seismicity, offsets in the faults, changes in fault trends and focal mechanisms are closely related. No relation was found between earthquake activity and both-ground water table fluctuations and water temperatures measured in wells located around the Kalabsha area. The peak ground acceleration is estimated in the dam site based on strong ground motion simulation. This seismic hazard analyses have indicated that AHD is stable with the present seismicity. The earthquake epicenters have recently took place approximately 5 km west of the AHD structure. This suggests that AHD dam must be

  2. Understanding the Role of Reservoir Size on Probable Maximum Precipitation

    Science.gov (United States)

    Woldemichael, A. T.; Hossain, F.

    2011-12-01

    This study addresses the question 'Does surface area of an artificial reservoir matter in the estimation of probable maximum precipitation (PMP) for an impounded basin?' The motivation of the study was based on the notion that the stationarity assumption that is implicit in the PMP for dam design can be undermined in the post-dam era due to an enhancement of extreme precipitation patterns by an artificial reservoir. In addition, the study lays the foundation for use of regional atmospheric models as one way to perform life cycle assessment for planned or existing dams to formulate best management practices. The American River Watershed (ARW) with the Folsom dam at the confluence of the American River was selected as the study region and the Dec-Jan 1996-97 storm event was selected for the study period. The numerical atmospheric model used for the study was the Regional Atmospheric Modeling System (RAMS). First, the numerical modeling system, RAMS, was calibrated and validated with selected station and spatially interpolated precipitation data. Best combinations of parameterization schemes in RAMS were accordingly selected. Second, to mimic the standard method of PMP estimation by moisture maximization technique, relative humidity terms in the model were raised to 100% from ground up to the 500mb level. The obtained model-based maximum 72-hr precipitation values were named extreme precipitation (EP) as a distinction from the PMPs obtained by the standard methods. Third, six hypothetical reservoir size scenarios ranging from no-dam (all-dry) to the reservoir submerging half of basin were established to test the influence of reservoir size variation on EP. For the case of the ARW, our study clearly demonstrated that the assumption of stationarity that is implicit the traditional estimation of PMP can be rendered invalid to a large part due to the very presence of the artificial reservoir. Cloud tracking procedures performed on the basin also give indication of the

  3. Quantifying the robustness of optimal reservoir operation for the Xinanjiang-Fuchunjiang Reservoir Cascade

    NARCIS (Netherlands)

    Vonk, E.; Xu, YuePing; Booij, Martijn J.; Augustijn, Dionysius C.M.

    2016-01-01

    In this research we investigate the robustness of the common implicit stochastic optimization (ISO) method for dam reoperation. As a case study, we focus on the Xinanjiang-Fuchunjiang reservoir cascade in eastern China, for which adapted operating rules were proposed as a means to reduce the impact

  4. Quantification of Libby Reservoir Levels Needed to Maintain or Enhance Reservoir Fisheries, 1983-1987 Methods and Data Summary.

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, Ian

    1989-12-01

    Libby Reservoir was created under an International Columbia River Treaty between the United States and Canada for cooperative water development of the Columbia River Basin. The authorized purpose of the dam is to provide power, flood control, and navigation and other benefits. Research began in May 1983 to determine how operations of Libby dam impact the reservoir fishery and to suggest ways to lessen these impacts. This study is unique in that it was designed to accomplish its goal through detailed information gathering on every trophic level in the reservoir system and integration of this information into a quantitative computer model. The specific study objectives are to: quantify available reservoir habitat, determine abundance, growth and distribution of fish within the reservoir and potential recruitment of salmonids from Libby Reservoir tributaries within the United States, determine abundance and availability of food organisms for fish in the reservoir, quantify fish use of available food items, develop relationships between reservoir drawdown and reservoir habitat for fish and fish food organisms, and estimate impacts of reservoir operation on the reservoir fishery. 115 refs., 22 figs., 51 tabs.

  5. WAC Bennett Dam - the characterization of a crest sinkhole

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R.A.; Gaffran, P.C. [British Columbia Hydro, Burnaby, BC (Canada); Watts, B.D. [Klohn-Crippen Consultants Ltd., Richmond, BC (Canada); Sobkowicz, J.C. [Thurber Engineering Ltd., Vancouver, BC (Canada); Kupper, A.G. [AGRA Earth and Environmental, Edmonton, AB (Canada)

    1998-11-01

    In June, 1996, a small hole was discovered in the asphaltic concrete road on the crest of the 183 m high WAC Bennett Dam on the Peace River in northeastern British Columbia. Examination of the hole resulted in a sinkhole on the dam crest. The sinkhole was 2.5 m in diameter and 7 m deep. Speculation was that the cavity was likely associated in some way with a buried survey benchmark tube. An investigation was immediately planned and executed to characterize the sinkhole, to determine the extent of damage and the safety status of this very large dam. British Columbia`s Dam Safety Regulator made the decision to lower the reservoir level. During the reservoir drawdown, various surface geophysical techniques were used to investigate the condition of the dam beyond the sinkholes. Intrusive investigations of the sinkhole were also planned. This involved trial drilling and downhole geophysical surveys in intact portions of the core at locations far from the sinkhole. The objectives and criteria developed for the investigation program are summarized. Scope of key activities at the sinkhole and important lessons learned during the investigation are also described. 9 refs., 15 figs.

  6. Dam Construction in Lancang-Mekong River Basin Could Mitigate Future Flood Risk From Warming-Induced Intensified Rainfall: Dam Mitigate Flood Risk in Mekong

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Changjiang Institute of Survey, Planning, Design and Research, Wuhan China; Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Lu, Hui [Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Joint Center for Global Change Studies, Beijing China; Ruby Leung, L. [Pacific Northwest National Laboratory, Richland WA USA; Li, Hong-Yi [Department of Land Resources and Environmental Sciences and Institute on Ecosystems, Montana State University, Bozeman MT USA; Zhao, Jianshi [State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing China; Tian, Fuqiang [State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing China; Yang, Kun [Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Joint Center for Global Change Studies, Beijing China; Sothea, Khem [Mekong Institute of Cambodia, Phnom Penh Cambodia

    2017-10-25

    Water resources management, in particular flood control, in the Mekong River Basin (MRB) faces two key challenges in the 21st century: climate change and dam construction. A large scale distributed Geomorphology-Based Hydrological Model coupled with a simple reservoir regulation model (GBHM-MK-SOP) is used to investigate the relative effects of climate change and dam construction on the flood characteristics in the MRB. Results suggest an increase in both flood magnitude and frequency under climate change, which is more severe in the upstream basin and increases over time. However, dam construction and stream regulation reduce flood risk consistently throughout this century, with more obvious effects in the upstream basin where larger reservoirs will be located. The flood mitigation effect of dam regulation dominates over the flood intensification effect of climate change before 2060, but the latter emerges more prominently after 2060 and dominates the flood risk especially in the lower basin.

  7. Dams and Intergovernmental Transfers

    Science.gov (United States)

    Bao, X.

    2012-12-01

    Gainers and Losers are always associated with large scale hydrological infrastructure construction, such as dams, canals and water treatment facilities. Since most of these projects are public services and public goods, Some of these uneven impacts cannot fully be solved by markets. This paper tried to explore whether the governments are paying any effort to balance the uneven distributional impacts caused by dam construction or not. It showed that dam construction brought an average 2% decrease in per capita tax revenue in the upstream counties, a 30% increase in the dam-location counties and an insignificant increase in downstream counties. Similar distributional impacts were observed for other outcome variables. like rural income and agricultural crop yields, though the impacts differ across different crops. The paper also found some balancing efforts from inter-governmental transfers to reduce the unevenly distributed impacts caused by dam construction. However, overall the inter-governmental fiscal transfer efforts were not large enough to fully correct those uneven distributions, reflected from a 2% decrease of per capita GDP in upstream counties and increase of per capita GDP in local and downstream counties. This paper may shed some lights on the governmental considerations in the decision making process for large hydrological infrastructures.

  8. The management of the Diama reservoir (Senegal River)

    Science.gov (United States)

    Duvail, S.; Hamerlynck, O.

    2003-04-01

    The Senegal River is regulated by 2 dams built in the 1980's by the "Organisation pour la Mise en Valeur du fleuve Sénégal" (OMVS), a river basin management organisation grouping Mali, Senegal and Mauritania. The initial objectives of OMVS, which were to regulate the Senegal flows in order to develop irrigated agriculture, produce hydropower and facilitate river navigation has been only partially met. The maintenance of the annual flood by the upstream dam (Manantali), initially to be phased out when irrigated agriculture would have replaced the traditional recession agriculture, is now scheduled to continue indefinitely on the basis of socio-economic and environmental concerns. This change of mindset has however not affected the management of the downstream dam (Diama). Initially conceived as a salt-wedge dam, its function evolved to a reservoir dam with a high and constant water level. During the dry season, the water level is maintained high and constant in order to reduce the pumping costs for the irrigated agriculture in the delta. During the flood season (July-October) the dam is primarily managed for risk avoidance: limit flooding downstream of the dam (especially the city of St. Louis) and secure the infrastructure of the dam itself. The permanent freshwater reservoir lake has adverse effects on ecosystems, on human and animal health and a high social cost for the traditional stakeholders of the deltaic floodplain (fishermen, livestock keepers and gatherers). Upstream of the reservoir there is an excess of stagnant freshwater and managers are confronted with the development of invasive species while substantial downstream flooding is essential for the estuarine ecosystems and local livelihoods. The presentation will review the different approaches to the management of the Diama reservoir and proposes different management scenarios and compares their economical, environmental, and social costs and benefits.

  9. Greenhouse gas emissions from reservoir water surfaces: A new global synthesis

    Science.gov (United States)

    Collectively, reservoirs created by dams are thought to be an important source ofgreenhouse gases (GHGs) to the atmosphere. So far, efforts to quantify, model, andmanage these emissions have been limited by data availability and inconsistenciesin methodological approach. Here we ...

  10. Hydraulic fracture considerations in oil sand overburden dams

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R.; Madden, B.; Danku, M. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2008-07-01

    This paper discussed hydraulic fracture potential in the dry-filled temporary dams used in the oil sands industry. Hydraulic fractures can occur when reservoir fluid pressures are greater than the minimum stresses in a dam. Stress and strain conditions are influenced by pore pressures, levels of compaction in adjacent fills as well as by underlying pit floor and abutment conditions. Propagation pressure and crack initiation pressures must also be considered in order to provide improved hydraulic fracture protection to dams. Hydraulic fractures typically result in piping failures. Three cases of hydraulic fracture at oil sands operations in Alberta were presented. The study showed that hydraulic fracture failure modes must be considered in dam designs, particularly when thin compacted lift of dry fill are used to replace wetted clay cores. The risk of hydraulic fractures can be reduced by eliminating in situ bedrock irregularities and abutments. Overpressure heights, abutment sloping, and the sloping of fills above abutments, as well as the dam's width and base conditions must also be considered in relation to potential hydraulic fractures. It was concluded that upstream sand beaches and internal filters can help to prevent hydraulic fractures in dams in compacted control zones. 5 refs., 16 figs.

  11. Discussion on the Safety Factors of Slopes Recommended for Small Dams

    Directory of Open Access Journals (Sweden)

    Jan Vrubel

    2017-01-01

    Full Text Available The design and assessment of the slope stability of small embankment dams is usually not carried out using slope stability calculations but rather by the comparison of proposed or existing dam slopes with those recommended by technical standards or guidelines. Practical experience shows that in many cases the slopes of small dams are steeper than those recommended. However, most of such steeper slopes at existing dams do not exhibit any visible signs of instability, defects or sliding. For the dam owner and also for dam stability engineers, the safety of the slope, expressed e.g. via a factor of safety, is crucial. The aim of this study is to evaluate the safety margin provided by recommended slopes. The factor of safety was evaluated for several dam shape and layout variants via the shear strength reduction method using PLAXIS software. The study covers various dam geometries, dam core and shoulder positions and parameter values of utilised soils. Three load cases were considered: one with a steady state seepage condition and two with different reservoir water level drawdown velocities – standard and critical. As numerous older small dams lack a drainage system, variants with and without a toe drain were assessed. Calculated factors of safety were compared with required values specified by national standards and guidelines.

  12. Special design issues related to the G. Ross Lord Dam constructed in Metropolitan Toronto

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, V.A. [Jacques Whitford and Associates Ltd., Vancouver, BC (Canada); Tawil, A.H. [Acres International Ltd., Niagara Falls, ON (Canada); Haley, D.R. [Toronto Region and Conservation Authority, Downsview, ON (Canada)

    2002-07-01

    This paper describes the special considerations required to build a flood control dam in a metropolitan area that holds major city infrastructures such as power transmission towers, pipelines, sanitary sewers and graveyards. The paper refers to the G. Ross Lord Dam, a 20 m high earth fill flood control dam which was constructed in 1973 on the West Branch of the Don River in Toronto. It was built following recommendations after Hurricane Hazel caused widespread flooding and the death of 81 people in 1954. The dam includes a concrete chute spillway and stilling basin. The geotechnical design of the dam was described along with the dam structures and the methods used to flood proof the infrastructure. The dam has a sloping impervious core and an upstream blanket to reduce seepage. Seepage control is provided by a drainage blanket and a chimney drain. A main overflow spillway was constructed on the south abutment, and a low level outlet was constructed at the base of the dam to accommodate normal river flows through the dam. Most of the water level control during a flood event is provided by the main overflow spillway. Spillway slab anchor keys prevent down slope creep of the slabs. The dam, the spillway and the reservoir structure have performed well since construction. 6 refs., 10 figs.

  13. The Politics, Development and Problems of Small Irrigation Dams in Malawi: Experiences from Mzuzu ADD

    Directory of Open Access Journals (Sweden)

    Bryson Gwiyani Nkhoma

    2011-10-01

    Full Text Available The paper examines the progress made regarding the development of small irrigation dams in Malawi with the view of establishing their significance in improving rural livelihoods in the country. The paper adopts a political economy theory and a qualitative research approach. Evidence from Mzuzu Agricultural Development Division (ADD, where small reservoirs acquire specific relevance, shows that despite the efforts made, the development of small dams is making little progress. The paper highlights that problems of top-down planning, high investment costs, negligence of national and local interests, over-dependency on donors, and conflicts over the use of dams – which made large-scale dams unpopular in the 1990s – continue to affect the development of small irrigation dams in Malawi. The paper argues that small irrigation dams should not be simplistically seen as a panacea to the problems of large-scale irrigation dams. Like any other projects, small dams are historically and socially constructed through interests of different actors in the local settings, and can only succeed if actors, especially those from formal institutions, develop adaptive learning towards apparent conflicting relations that develop among them in the process of implementation. In the case of Mzuzu ADD, it was the failure of the government to develop this adaptive learning to the contestations and conflicts among these actors that undermined successful implementation of small irrigation dams. The paper recommends the need to consider local circumstances, politics, interests, rights and institutions when investing in small irrigation dams.

  14. Three Sisters Dam: Investigations and monitoring

    International Nuclear Information System (INIS)

    Slopek, R.J.; Courage, L.J.R.; Keys, R.A.

    1990-01-01

    The geotechnical investigations, monitoring and interpretation of data associated with the evaluation of the Three Sisters Dam, which has been suffering from excessive seepage and is in need of enhancement, are outlined. The Three Sisters Dam is located in the continental ranges of the Rocky Mountains in Alberta, impounding the Spray Reservoir, and is founded on 60 m of interbedded sand, gravel, silt and clay layers. The computer code PC-SEEP was used to evaluate seepage. Details are provided of drilling, ground-penetrating radar surveys, seismic surveys, penstock inspection, sinkhole activity, piezometer monitoring, silt wells, settlement monuments, and tailrace monitoring. The intensive investigations of the foundations showed that they consist of a complex formation of interfingered stratified layers and leases of talus and glaciofluvial deposits. Due to the depth and nature of these materials drill hole penetration was limited to the use of the Becker hammer. This equipment successfully delineated the major soil horizons of the foundation. The continued information attained from inspection, drilling, testing, radar surveys, seismic work, monitoring of piezometers, leakage, silt wells and settlement monuments indicated that there are no large voids within the foundation of the dam. 2 refs., 12 figs

  15. Dam spills and fishes; Eclusees et poissons

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This short paper reports the main topics discussed during the two days of the annual colloquium of the Hydro-ecology Committee of EdF. The first day was devoted to the presentation of the joint works carried out by EdF, the Paul-Sabatier University (Toulouse), the Provence St-Charles University (Marseille), the ENSAT (Toulouse) and the CEMAGREF (Lyon and Aix-en-Provence) about the environmental impact of dam spills on the aquatic flora and fauna downstream. A synthesis and recommendations were presented for the selection and characterization of future sites. The second day was devoted to the hydro-ecology study of the dam reservoir of Petit-Saut (French Guyana): water reoxygenation, quality evolution, organic matter, plankton, invertebrates and fishes. The 134 French dams concerned by water spills have been classified according to the frequency of spills, the variations of flow rates created, and their impacts on fishing, walking, irrigation, industry, drinking water, navigation, bathing. Particular studies on different sites have demonstrated the complexity of the phenomena involved concerning the impact on the ecosystems and the water quality. (J.S.).

  16. Geomorphic and habitat response to a large-dam removal in a Mediterranean river

    Science.gov (United States)

    Harrison, L.; East, A. E.; Smith, D. P.; Bond, R.; Logan, J. B.; Nicol, C.; Williams, T.; Boughton, D. A.; Chow, K.

    2017-12-01

    The presence of large dams has fundamentally altered physical and biological processes in riverine ecosystems, and dam removal is becoming more common as a river restoration strategy. We used a before-after-control-impact study design to investigate the geomorphic and habitat response to removal of 32-m-high San Clemente Dam on the Carmel River, CA. The project represents the first major dam removal in a Mediterranean river and is also unique among large dam removals in that most reservoir sediment was sequestered in place. We found that in the first year post-removal, a sediment pulse migrated 3.5 km downstream, filling pools and the interstitial pore spaces of gravels with sand. These sedimentary and topographic changes initially reduced the overall quality of steelhead (O. mykiss) spawning and rearing habitat in impacted reaches. Over the second winter after dam removal, a sequence of high flows flushed large volumes of sand from pools and mobilized the river bed throughout much of the active channel. The floods substantially altered fluvial evolution in the upper part of the reservoir, promoting new avulsion and the subsequent delivery of gravel and large wood to below dam reaches. These geomorphic processes increased the availability of spawning-sized gravel and enhanced channel complexity in reaches within several km of the former dam, which should improve habitat for multiple life stages of steelhead. Results indicate that when most reservoir sediment remains impounded, high flows become more important drivers of geomorphic and habitat change than dam removal alone. In such cases, the rates at which biophysical processes are reestablished will depend largely on post-dam removal flow sequencing and the upstream supply of sediment and large wood.

  17. Small dams need better management

    Science.gov (United States)

    Balcerak, Ernie

    2012-03-01

    Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four states in Australia, and developed policy benchmarks and best practices for small-dam management. Small dams, often just several meters high and typically privately owned by individual farmers, have historically caused major damage when they fail. For instance, in China in 1975, 230,000 people died when two large dams failed because of the cumulative failure of 60 smaller upstream dams. In the United States, in 1977 the 8-meter-high Kelly Barnes Lake dam failed, killing 39 people. Many other small-dam failures around the world have resulted in casualties and severe ecological and economic damage.

  18. The Impact of a Check Dam on Groundwater Recharge and Sedimentation in an Ephemeral Stream

    Directory of Open Access Journals (Sweden)

    Hakan Djuma

    2017-10-01

    Full Text Available Despite the widespread presence of groundwater recharge check dams, there are few studies that quantify their functionality. The objectives of this study are (i to assess groundwater recharge in an ephemeral river with and without a check dam and (ii to assess sediment build-up in the check-dam reservoir. Field campaigns were carried out to measure water flow, water depth, and check-dam topography to establish water volume, evaporation, outflow, and recharge relations, as well as sediment build-up. To quantify the groundwater recharge, a water-balance approach was applied at two locations: at the check dam reservoir area and at an 11 km long natural stretch of the river upstream. Prediction intervals were computed to assess the uncertainties of the results. During the four years of operation, the check dam (storage capacity of 25,000 m3 recharged the aquifer with an average of 3.1 million m3 of the 10.4 million m3 year−1 of streamflow (30%. The lower and upper uncertainty limits of the check dam recharge were 0.1 and 9.6 million m3 year−1, respectively. Recharge from the upstream stretch was 1.5 million m3 year−1. These results indicate that check dams are valuable structures for increasing groundwater resources in semi-arid regions.

  19. Rock Mass Behavior Under Hydropower Embankment Dams: A Two-Dimensional Numerical Study

    Science.gov (United States)

    Bondarchuk, A.; Ask, M. V. S.; Dahlström, L.-O.; Nordlund, E.

    2012-09-01

    Sweden has more than 190 large hydropower dams, of which about 50 are pure embankment dams and over 100 are concrete/embankment dams. This paper presents results from conceptual analyses of the response of typical Swedish rock mass to the construction of a hydropower embankment dam and its first stages of operation. The aim is to identify locations and magnitudes of displacements that are occurring in the rock foundation and grout curtain after construction of the dam, the first filling of its water reservoir, and after one seasonal variation of the water table. Coupled hydro-mechanical analysis was conducted using the two-dimensional distinct element program UDEC. Series of the simulations have been performed and the results show that the first filling of the reservoir and variation of water table induce largest magnitudes of displacement, with the greatest values obtained from the two models with high differential horizontal stresses and smallest spacing of sub-vertical fractures. These results may help identifying the condition of the dam foundation and contribute to the development of proper maintenance measures, which guarantee the safety and functionality of the dam. Additionally, newly developed dams may use these results for the estimation of the possible response of the rock foundation to the construction.

  20. Phenotypic plasticity in fish life-history traits in two neotropical reservoirs : Petit-Saut Reservoir in French Guiana and Brokopondo Reservoir in Suriname

    OpenAIRE

    Merona de, Bernard; Mol, J.; Vigouroux, R.; Chaves, P. D.

    2009-01-01

    Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years) and the ...

  1. Carbon emission from global hydroelectric reservoirs revisited.

    Science.gov (United States)

    Li, Siyue; Zhang, Quanfa

    2014-12-01

    Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO2)/year and 18.7 Tg methane (CH4)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO2 and 67 % CH4 of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO2/kWh and 5.7 g CH4/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO2eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs.

  2. Assessment of check-dam groundwater recharge with water-balance calculations

    Science.gov (United States)

    Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

    2017-04-01

    Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without

  3. Risk Perception Analysis Related To Existing Dams In Italy

    Science.gov (United States)

    Solimene, Pellegrino

    2013-04-01

    In the first part of this work, the progress of Italian National Rules about dams design, construction and operation are presented to highlight the strong connection existing between the promulgation of new decrees, as a consequence of a dam accidents, and the necessity to prevent further loss of lives and goods downstream. Following the Gleno Dam failure (1923), a special Ministerial Committee wrote out the first Regulations and made the proposal to establish, within the High Council of Public Works, a special department that become soon the "Dam Service", with the tasks of control and supervision about construction and operation phases of the dams and their reservoirs. A different definition of tasks and the structure of Dam Service were provided in accordance with law n° 183/1989, which transferred all the technical services to the Office of the Prime Minister; the aim was to join the Dam Office with the Department for National Technical Services, with the objective of increasing the knowledge of the territory and promoting the study on flood propagation downstream in case of operations on bottom outlet or hypothetical dam-break. In fact, population living downstream is not ready to accept any amount of risk because has not a good knowledge of the efforts of experts involved in dam safety, both from the operators and from the safety Authority. So it's important to optimize all the activities usually performed in a dam safety program and improve the emergency planning as a response to people's primary needs and feeling about safety from Civil Protection Authority. In the second part of the work, a definition of risk is provided as the relationship existing between probability of occurrence and loss, setting out the range within to plan for prevention (risk mitigation), thanks to the qualitative assessment of the minimum safety level that is suited to assign funds to plan for Civil Protection (loss mitigation). The basic meaning of the reliability of a zoned

  4. Dam safety investigations of the concrete structures of Hugh Keenleyside dam

    International Nuclear Information System (INIS)

    Hanna, A.W.; Nunn, J.O.H.; Cornish, L.; Northcott, P.

    1993-01-01

    The Hugh Keenleyside dam is located on the Columbia River in southeastern British Columbia, and impounds Arrow Lakes Reservoir which has a live storage of 8.8 km 3 and drains an area of 36,000 km 2 . It consists of a number of concrete structures, with a total length of 360 m and a maximum height of 58 m, and an earthfill embankment which spans across the original river channel. The 450 m long zoned earthfill dam is founded on pervious alluvium over 150 m deep. It has a sloping impervious core constructed from glacial till which extends 670 m upstream of the dam. This impervious blanket extends over the full width of the reservoir and is connected to the upstream face of the concrete structures. The results of a dam safety study, which was carried out due to the presence of high uplift pressures at some parts of the foundation, and stability concerns, are presented. The investigation concluded that the high uplift pressures were due to a localized defect in the upstream blanket and did not indicate any general deterioration of the blanket. Techniques that were found to be of particular use in the study for defining the source and nature of the foundation defects were: temperature surveys of flows from piezometers, cells and drains; air injection tests; and pressure response testing of cells, piezometers and drains to establish foundation interconnections. The concrete structures met the stability criteria for all load cases considered except for the navigation lock and the low level outlets. 3 refs., 6 figs

  5. 76 FR 11679 - Drawbridge Operation Regulation; Shark River (South Channel), Belmar, NJ

    Science.gov (United States)

    2011-03-03

    ... Operation Regulation; Shark River (South Channel), Belmar, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... temporary deviation from the regulations governing the operation of the S71 Bridge across Shark River (South... Bridge, a bascule lift drawbridge, across Shark River (South Channel), at mile 0.8, in Belmar, NJ, has a...

  6. 77 FR 55455 - Foreign-Trade Zone 235-Lakewood, NJ, Authorization of Production Activity, Cosmetic Essence...

    Science.gov (United States)

    2012-09-10

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-31-2012] Foreign-Trade Zone 235--Lakewood, NJ, Authorization of Production Activity, Cosmetic Essence Innovations, LLC, (Fragrance Bottling), Holmdel, NJ Cosmetic Essence Innovations, LLC (CEI) submitted a notification of proposed production activity to the...

  7. 77 FR 26737 - Foreign-Trade Zone 235-Lakewood, NJ: Notification of Proposed Production Activity; Cosmetic...

    Science.gov (United States)

    2012-05-07

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-31-2012] Foreign-Trade Zone 235--Lakewood, NJ: Notification of Proposed Production Activity; Cosmetic Essence Innovations, LLC (Fragrance Bottling); Holmdel, NJ Cosmetic Essence Innovations, LLC (CEI) has submitted a notification of proposed production...

  8. Wynoochee Dam Foundation Report

    Science.gov (United States)

    1988-01-01

    schists and in propylitized andesite volcanic rocks. Tests on chlorite-bearing graywackes (Lumni Island and Robe Quarry, Seattle District) and... propylitized chlorite-bearing andesites (Blue River and Lookout Point Dams, Portland District) have shown these rocks to be durable materials with only minor

  9. Penatagunaan Kawasan Sekitar Waduk dalam Upaya Menjaga Kelestariannya (Model DAM

    Directory of Open Access Journals (Sweden)

    Hari Nugroho

    2015-04-01

    Full Text Available Kedungombo reservoir has provided a substantial contribution in improving the welfare of society, so that its existence should be preserved. As time goes there are some issues Kedungombo. The problems are concerning with the condition of reservoirs, dams and problems in the surrounding area. To preserve the reservoirs, conservation efforts by reviewing the management of the reservoir area. The study results showed that there was no master plan to utilize the management of Kedungombo catchment. For this reason, it is proposed the development of Kedungombo area is directed to recover the potential and cultivitation areas, to empower community and to strengthen the protected and cultivitation areas in order to concerved Reservoir. Kedungombo area is directed as a center of tourism services, housing, aquaculture and local protected areas. Reservoir area is specified to 500 meters from the boundary of the highest reservoir water level, so hopefully all the activities in this area follows specified to the regulations. It is recommended to develop an institution to manage Kedungombo Area. The institution should be able to implementation the principle of management i.e. transparency, open to various parties; can be accounted for; clarity the limits of authority, territory under the following management roles and responsibilities and apply the principles and legal norms in the management of the Area Kedungombo. The model is expected to be implemented and become a model for Reservoir Management in Indonesia.

  10. Great landslide events in Italian artificial reservoirs

    Directory of Open Access Journals (Sweden)

    A. Panizzo

    2005-01-01

    Full Text Available The empirical formulations to forecast landslide generated water waves, recently defined in the framework of a research program funded by the Italian National Dam Office RID (Registro Italiano Dighe, are here used to study three real cases of subaerial landslides which fell down italian artificial reservoirs. It is well known that impulse water waves generated by landslides constitute a very dangerous menace for human communities living in the shoreline of the artificial basin or downstream the dam. In 1963, the menace became tragedy, when a 270 millions m3 landslide fell down the Vajont reservoir (Italy, generated an impulse wave which destroyed the city of Longarone, and killed 2000 people. The paper is aimed at presenting the very satisfactorily reproduction of the events at hand by using forecasting formulations.  

  11. Great landslide events in Italian artificial reservoirs

    Science.gov (United States)

    Panizzo, A.; de Girolamo, P.; di Risio, M.; Maistri, A.; Petaccia, A.

    2005-09-01

    The empirical formulations to forecast landslide generated water waves, recently defined in the framework of a research program funded by the Italian National Dam Office RID (Registro Italiano Dighe), are here used to study three real cases of subaerial landslides which fell down italian artificial reservoirs. It is well known that impulse water waves generated by landslides constitute a very dangerous menace for human communities living in the shoreline of the artificial basin or downstream the dam. In 1963, the menace became tragedy, when a 270 millions m3 landslide fell down the Vajont reservoir (Italy), generated an impulse wave which destroyed the city of Longarone, and killed 2000 people. The paper is aimed at presenting the very satisfactorily reproduction of the events at hand by using forecasting formulations.

  12. Anthropogenic Water Uses and River Flow Regime Alterations by Dams

    Science.gov (United States)

    Ferrazzi, M.; Botter, G.

    2017-12-01

    Dams and impoundments have been designed to reconcile the systematic conflict between patterns of anthropogenic water uses and the temporal variability of river flows. Over the past seven decades, population growth and economic development led to a marked increase in the number of these water infrastructures, so that unregulated free-flowing rivers are now rare in developed countries and alterations of the hydrologic cycle at global scale have to be properly considered and characterized. Therefore, improving our understanding of the influence of dams and reservoirs on hydrologic regimes is going to play a key role in water planning and management. In this study, a physically based analytic approach is combined to extensive hydrologic data to investigate natural flow regime alterations downstream of dams in the Central-Eastern United States. These representative case studies span a wide range of different uses, including flood control, water supply and hydropower production. Our analysis reveals that the most evident effects of flood control through dams is a decrease in the intra-seasonal variability of flows, whose extent is controlled by the ratio between the storage capacity for flood control and the average incoming streamflow. Conversely, reservoirs used for water supply lead to an increase of daily streamflow variability and an enhanced inter-catchment heterogeneity. Over the last decades, the supply of fresh water required to sustain human populations has become a major concern at global scale. Accordingly, the number of reservoirs devoted to water supply increased by 50% in the US. This pattern foreshadows a possible shift in the cumulative effect of dams on river flow regimes in terms of inter-catchment homogenization and intra-annual flow variability.

  13. Geophysical investigation of seepage beneath an earthen dam.

    Science.gov (United States)

    Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

    2015-01-01

    A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone. © 2014, National Ground Water Association.

  14. Geomorphic and Ecological Issues in Removal of Sediment-Filled Dams in the California Coast Ranges (Invited)

    Science.gov (United States)

    Kondolf, G. M.; Oreilly, C.

    2010-12-01

    Water-supply reservoirs in the actively eroding California Coast Ranges are vulnerable to sediment filling, thus creating obsolete impounding dams (Minear & Kondolf 2009). Once full of sediment, there is more impetus to remove dams for public safety and fish passage, but managing accumulated sediments becomes a dominant issue in dam removal planning. We analyzed the planning process and sediment management analyses for five dams, all of which have important ecological resources but whose dam removal options are constrained by potential impacts to downstream urban populations. Ringe Dam on Malibu Ck, Matilija Dam on the Ventura River, Searsville Dam on San Francisquito Ck, and Upper York Creek Dam on York Ck cut off important habitat for anadromous steelhead trout (Oncorhynchus mykiss). San Clemente Dam on the Carmel River has a working fish ladder, but only some of the migratory steelhead use it. By virtue of having filled with sediment, all five dams are at greater risk of seismic failure. San Clemente Dam is at greater risk because its foundation is on alluvium (not bedrock), and the poor-quality concrete in Matilija Dam is deteriorating from an akali-aggregate reaction. Simply removing the dams and allowing accumulated sediments to be transported downstream is not an option because all these rivers have extremely expensive houses along downstream banks and floodplains, so that allowing the downstream channel to aggrade with dam-dervied sediments could expose agencies to liability for future flood losses. Analyses of potential sediment transport have been based mostly on application of tractive force models, and have supported management responses ranging from in-situ stabilization (San Clemente and Matilija) to removal of stored sediment (York) to annual dredging to maintain capacity and prevent sediment passing over the dam (proposed for Searsville).

  15. Abandonment of the low level outlet structure at the McGregor South Dam

    Energy Technology Data Exchange (ETDEWEB)

    Mack, D.L; Murray, T.K. [Klohn-Crippen Consultants Ltd., Calgary, AB (Canada); Soutar, B.M. [Alberta Transportation, Edmonton, AB (Canada)

    2008-07-01

    The Carseland-Bow River Headworks (CBRH) is a major multi-purpose water delivery system, situated in southern Alberta. It supplies water to 87,000 hectares of agricultural land and several municipalities. The system was originally built starting in 1909. It consists of diversion works on the Bow River, 65 kilometres of canal, and the McGregor and Little Bow reservoirs. In the 1950s, the system was rehabilitated by the Prairie Farm Rehabilitation Administration (PFRA), and Travers Reservoir was added in 1954. In 1973, ownership and operation of the CBRH system was turned over to Alberta Environment. In 2001, Alberta Transportation implemented a major program to rehabilitate and upgrade the CBRH system. This program included increasing the capacity of the canals and structures, and upgrading the dams to meet current dam safety guidelines. The project involved raising the north and south dams, providing an auxiliary spillway to accommodate the probable maximum flood (PMF), and rehabilitating the existing reservoir inlet and low level outlet structures. This paper discussed the abandonment of the existing low level outlet structure located within the south dam. The paper discussed the existing dams and outlet structure as well as the south dam and outlet structure. The abandonment of the existing low level outlet structure was discussed in terms of general construction; demolition; upstream conduits and gatewell; and downstream conduit. Several illustrations and photographs of the dam and the demolition were presented. It was concluded that the in-place abandonment of the existing low level outlet structure at the McGregor South Dam provides significant advantages, including eliminating the need to construct and remove an extensive cofferdam within the reservoir. 6 refs., 2 tabs., 4 figs.

  16. A brief history of 20th century dam construction and a look into the future

    Science.gov (United States)

    van de Giesen, Nick

    2010-05-01

    In this presentation, an overview is given of global dam building activities in the 20th century. Political, economical and hydrological factors shaped the building of large dams. The development of the relations between these three factors and dam building over time is examined. One can argue whether or not history is simply "one damn thing after another" but the second half of the 20th century suggests that history is at least reflected by the construction of one dam after another. The financial crisis of the 1930's started the first construction wave of large hydropower dams in the United States. This wave continued into the Second World War. During the Cold War, the weapon race between the USA and USSR was accompanied by a parallel neck-and-neck race in dam construction. By the 1970's, dam construction in the USA tapered off, while that in the USSR continued until its political disintegration. In China, we see two spurts in dam development, the first one coinciding with the disastrous Great Leap Forward and the second with the liberalization of the Chinese economy after the fall of the Berlin Wall. Economic and political events thus shaped to an important extent decisions surrounding the construction of large dams. Clearly, there are some hydrological prerequisites for the construction of dams. The six largest dam building nations are USSR, Canada, USA, China, Brazil, and India, all large countries with ample water resources and mountain ranges. Australia has relatively little reservoir storage for the simple fact that most of this country is flat and dry. A few countries have relatively large amounts of reservoir storage. Especially Uganda (Owens Falls), Ghana (Akosombo), and Zimbabwe (Kariba) are examples of small countries where gorges in major rivers were "natural" places for large dams and reservoirs to be built early on. It seems that, deserts aside, the average potential storage capacity lies for most continents around 10 cm or about 50% of the total

  17. Estimated cumulative sediment trapping in future hydropower reservoirs in Africa

    Science.gov (United States)

    Lucía, Ana; Berlekamp, Jürgen; Zarfl, Christiane

    2017-04-01

    Despite a rapid economic development in Sub-Saharan Africa, almost 70% of the human population in this area remain disconnected from electricity access (International Energy Agency 2011). Mitigating climate change and a search for renewable, "climate neutral" electricity resources are additional reasons why Africa will be one key centre for future hydropower dam building, with only 8% of the technically feasible hydropower potential actually exploited. About 300 major hydropower dams with a total capacity of 140 GW are currently under construction (11.4%) or planned (88.6%) (Zarfl et al. 2015). Despite the benefits of hydropower dams, fragmentation of the rivers changes the natural flow, temperature and sediment regime. This has consequences for a high number of people that directly depend on the primary sector linked to rivers and floodplains. But sediment trapping in the reservoir also affects dam operation and decreases its life span. Thus, the objective of this work is to quantify the dimension of sediment trapping by future hydropower dams in African river basins. Soil erosion is described with the universal soil loss equation (Wischmeier & Smith 1978) and combined with the connectivity index (Cavalli et al. 2013) to estimate the amount of eroded soil that reaches the fluvial network and finally ends up in the existing (Lehner et al. 2011) and future reservoirs (Zarfl et al. 2015) per year. Different scenarios assuming parameter values from the literature are developed to include model uncertainty. Estimations for existing dams will be compared with literature data to evaluate the applied estimation method and scenario assumptions. Based on estimations for the reservoir volume of the future dams we calculated the potential time-laps of the future reservoirs due to soil erosion and depending on their planned location. This approach could support sustainable decision making for the location of future hydropower dams. References Cavalli, M., Trevisani, S., Comiti

  18. Status and Habitat Requirements of White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1989-1990 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nigro, Anthony A. (Oregon Department of Fish and Wildlife, Portland, OR)

    1990-09-01

    We report on our progress from April 1989 through March 1990 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW), Washington Department of Fisheries (WDF), US Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS). Study objectives addressed by each agency are to describe the life history and population dynamics of subadults and adults between Bonneville and McNary dams and evaluate the need and identify potential methods for protecting, mitigating and enhancing populations downstream from McNary Dam, to describe the white sturgeon recreational fishery between Bonneville and McNary dams, describe reproductive and early life history characteristics downstream from Bonneville Dam and describe life history and population dynamics of subadults and adults downstream from Bonneville Dam, to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available between Bonneville and McNary dams, and to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available downstream from Bonneville Dam. Our approach is to work concurrently downstream and upstream from Bonneville Dam. Upstream from Bonneville Dam we began work in the Dalles Reservoir in 1987 and expanded efforts to Bonneville Reservoir in 1988 and John Day Reservoir in 1989. Highlights from this work is also included. 47 refs., 33 figs., 66 tabs.

  19. Chinese engineers and scientists urge leadership to change Three Gorges Dam operating plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-26

    An appeal to the Chinese Leadership by a group of senior engineers, water management experts and academics about the dire consequences of filling the Three Gorges reservoir on the Yangtze River to 175 metres, is reported. Originally, the plan was to keep water levels behind the Three Gorges Dam at 156 metres for the first ten years of operation, in order to allow for resettlement of people displaced by building the dam, and to evaluate the impact of silt deposits on navigation and ports at the upper end of the reservoir. Plans have changed in 1997; the water level is now scheduled to rise to 175 metres in the sixth year of the dam's operation in order to maximize the dam's power output. The appeal by 53 experts warned the Chinese Government that the filling of the reservoir to 175 metres would displace 1.13 million people and raise the water level in the Yangtze River more than 10 metres at Chongqing City, submerging drainage outlets and backing up the city's sewage, as well as increase silt deposits, blocking shipping traffic along the Yangtze River. A parallel is drawn with the Sanmenxia Dam on the Yellow River. It was completed in 1960; it has proven to be useless for controlling floods while producing only one-third of its expected output due to massive silt build-up in the reservoir.

  20. Chinese engineers and scientists urge leadership to change Three Gorges Dam operating plan

    International Nuclear Information System (INIS)

    2000-01-01

    An appeal to the Chinese Leadership by a group of senior engineers, water management experts and academics about the dire consequences of filling the Three Gorges reservoir on the Yangtze River to 175 metres, is reported. Originally, the plan was to keep water levels behind the Three Gorges Dam at 156 metres for the first ten years of operation, in order to allow for resettlement of people displaced by building the dam, and to evaluate the impact of silt deposits on navigation and ports at the upper end of the reservoir. Plans have changed in 1997; the water level is now scheduled to rise to 175 metres in the sixth year of the dam's operation in order to maximize the dam's power output. The appeal by 53 experts warned the Chinese Government that the filling of the reservoir to 175 metres would displace 1.13 million people and raise the water level in the Yangtze River more than 10 metres at Chongqing City, submerging drainage outlets and backing up the city's sewage, as well as increase silt deposits, blocking shipping traffic along the Yangtze River. A parallel is drawn with the Sanmenxia Dam on the Yellow River. It was completed in 1960; it has proven to be useless for controlling floods while producing only one-third of its expected output due to massive silt build-up in the reservoir

  1. Surveillance of medium-size dams; Surveillance des barrages de taille moyenne

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    French hydro-power buildings belong to the government and are retroceded by the licence holder when the granting delay comes to an end. Experience has shown that less care is given by licence holders to the maintenance of medium-size dams that to big dams. For this reason, the French Ministry of Industry decided to harmonize and standardize the surveillance practices of medium-size dams. A circular was signed on May 23, 1997 which concerns the 10 to 20 m height dams with water reservoir volumes lower than the H{sup 2} x V{sup 0.5} criterion which is an evaluation of the potential risk of the dam. The surveillance modalities concern: the construction, the licence holder file, the first filling up, the operation, and the periodical safety inspections. (J.S.)

  2. Radiotracer studies in cavernous marble at Kamathikhairy Dam site, Pench Project (Maharashtra)

    International Nuclear Information System (INIS)

    Nath, Ravendra; Mahajan, N.M.; Vaidya, S.D.

    1982-01-01

    Radiotracer studies with tritiated water at Pench Project site conclusively proved that the cavernous marble upstream of the saddle dam is continuous with the marble occuring near the spillway portion of the main dam and that there is fast subterranean flow of water through the cavernous marble here. It is also established that this marble band upstream of the dam is interconnected with the marble band occuring in the vicinity of Pali village about 3 km downstream of the dam. Though big unclogged subterranean channels do not seem to exist in this region, which might have resulted in heavy leakage from the impounded reservoir, yet the possibility of some leakage of the water through the cavernous marble cannot be ruled out, due to the interconnection of the marble occuring upstream of the dam with the downstream marble band. (author)

  3. Expansion at Olympic Dam

    International Nuclear Information System (INIS)

    Lewis, C.

    1997-01-01

    The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date

  4. Status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam

    International Nuclear Information System (INIS)

    Nigro, A.A.

    1991-09-01

    We report on our progress from April 1990 through March 1991 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW), Washington Department of Fisheries (WDF), US Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS). Study objectives addressed by each agency are to describe the life history and population dynamics of subadults and adults between Bonneville and McNary dams and evaluate the need and identify potential methods for protecting, mitigating and enhancing populations downstream from NcNary Dam; to describe the white sturgeon recreational fishery between Bonneville and McNary dams, describe reproductive and early life history characteristics downstream from Bonneville Dam and describe life history and population dynamics of subadults and adults downstream from Bonneville Dam; to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available between Bonneville and McNary dams; and to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available downstream from Bonneville Dam. Our approach is to work concurrently downstream and upstream from Bonneville Dam. Upstream from Bonneville Dam we began work in the Dalles Reservoir in 1987 and expanded efforts to Bonneville Reservoir in 1988 and John Day Reservoir in 1989. Highlights of results of this work in the Dalles, Bonneville and John Day reservoirs are included in the four pages included in this report

  5. Use of a dam break model to assess flooding at Haddam Neck Nuclear Power Plant

    International Nuclear Information System (INIS)

    Scherrer, J.S.; Chery, D.L. Jr.

    1984-01-01

    Because of their proximity to necessary supplies of cooling water, nuclear power plants are susceptible to riverine flooding. Greater flood hazards exist where plants are located downstream of larger dams. The consequences of the Quabbin Reservoir dam failure on the Haddam Neck Nuclear Power Plant situated on the Connecticut River were investigated using a dam break flood routing model. Reasons for selecting a particular model are presented and the input assumption for the modeling process are developed. Relevant information concerning the level of manpower involvement is presented. The findings of this analysis demonstrate that the plant is adequately protected from the consequences of the postulated flood event

  6. Simulation analysis of temperature control on RCC arch dam of hydropower station

    Science.gov (United States)

    XIA, Shi-fa

    2017-12-01

    The temperature analysis of roller compacted concrete (RCC) dam plays an important role in their design and construction. Based on three-dimensional finite element method, in the computation of temperature field, many cases are included, such as air temperature, elevated temperature by cement hydration heat, concrete temperature during placing, the influence of water in the reservoir, and boundary temperature. According to the corresponding parameters of RCC arch dam, the analysis of temperature field and stress field during the period of construction and operation is performed. The study demonstrates that detailed thermal stress analysis should be performed for RCC dams to provide a basis to minimize and control the occurrence of thermal cracking.

  7. Contaminated Sediment Management in Dam Removals and River Restoration Efforts: Critical Need for Research and Policy Development

    Science.gov (United States)

    Evans, J. E.

    2015-12-01

    Over 1,000 U.S. dams have been removed (1975-2015) for reasons including obsolescence, liability concerns, water quality upgrades, fisheries, or ecosystem enhancements. Contaminated sediment can significantly complicate the approval process, cost, and timeline of a dam removal, or stop it entirely. In a dam removal, reservoir sediment changes from a sink to a source of contaminants. Recently, the Sierra Club sued to stop the removal of a large dam in Ohio because of the potential impact of phosphate releases on toxic algal blooms in Lake Erie. Heavy metals, PCBs, PAHs, pesticides, and petroleum hydrocarbons can be present in reservoir sediments. In a non-dam removal scenario, reservoir management tools range from "no action" to dredging, dewatering and removal, or sediment capping. But it is not clear how these reservoir management techniques apply to dam removals. Case studies show typically >80% of the reservoir sediment is eventually eroded, precluding sediment capping as a containment option. However, the released contaminants are diluted by mixing with "clean" sediment and are transported to different physio-chemical environments which may immobilize or biodegrade the contaminants. Poorly understood options include phased drawdown/reseeding the former reservoir to contain sediments, diking contaminant "hot spots," and addressing contaminant stratigraphy (where historical use created "hot layers" in the reservoir sediment). Research and policy development needs include: (1) assessment methods based on synergistic effects of multiple contaminants being present; (2) ways to translate the pre-removal contaminant concentrations to post-removal health risks downstream; (3) evaluation of management practices for contaminant "hot spots" and "hot layers;" (4) tools to forecast the presence of contaminated sediment using easily accessible information; and (5) ways to limit liability risk for organizations participating in dam removals involving contaminated sediment.

  8. Priority ranking for maintenance activities on embankment dams

    International Nuclear Information System (INIS)

    Chouinard, L.E.; Andersen, G.R.; Robichaud, J.G.; Blanchette, G.; Gervais, R.

    1998-01-01

    Operators of dams in Canada and the U.S. are steadily shifting from construction of new facilities to the maintenance and repairs of existing ones. This paper emphasized the importance of prioritizing maintenance activities on embankment dams whose maintenance needs vary from structure to structure. Two parallel procedures were developed, one for monitoring devices and the other for defense groups. Both procedures are intended to be used together to rate the condition of the embankment dams. The term 'defense groups' is used to refer to the collection of physical components on dams to prevent adverse conditions from occurring that would result in an uncontrolled release of the reservoir. The priority rankings and condition indices developed by means of this procedure reflects the judgment of a panel of engineers and geologists who implement them. They are not to be interpreted as an index of dam safety. While the process is sufficiently well developed to warrant wide-spread distribution, it is considered to be still in the developmental stage. Therefore, it should be used in conjunction with other parallel processes evaluating structural, mechanical and electrical features of the structure under consideration. 6 refs., 7 tabs

  9. Importance of using roller compacted concrete in techno-economic investigation and design of small dams

    Science.gov (United States)

    Rouissat, Bouchrit; Smail, N.; Zenagui, S.

    2017-12-01

    In recent years, and under constraints caused by persistent drought, Algeria has launched a new mobilization strategy for surface water resources from small and medium dams. However, by making a review of the studies and achievements of twenty small dams in the west of Algeria, some deficiencies appeared. In addition to reservoir siltation assessment, operation spillways have been the major constraint on the reliability of these types of dams. The objective of this paper is to use the roller compacted concrete (RCC) for small dams' design for the benefit it offers and its ability to incorporate spillways. The development of this reflection was applied to the Khneg Azir earth dam situated in southwest of Algeria. Its uncontrolled lateral spillway has registered significant damage following the flood of October 2005, amounted, at that time, to more than 100 million Algerian dinars (1 million US Dollars). The present research encompasses a technical and economical comparative analysis concerning multiple criteria dam design types coupled with the conjugation of the spillways. Thus, on the basis of financial estimates calculated for all design types, the variant RCC remains competitive with that of the earth dam's spillway isolated (Less than 40% of the cost). To assess the mechanical behavior of the foundations for both types of dams, (earth and RCC dams), numerical modeling has been undertaken, according to the comparative analysis of deformations in the foundations. Analysis of deformations showed that the average foundation deformations was between (0.052-0.85) m for earth dam and (0.023-0.373) m for RCC dam. These economical and technical considerations open up important prospects for the use of RCC in the design of small dams.

  10. Monitoring Thermal Pollution in Rivers Downstream of Dams with Landsat ETM+ Thermal Infrared Images

    Directory of Open Access Journals (Sweden)

    Feng Ling

    2017-11-01

    Full Text Available Dams play a significant role in altering the spatial pattern of temperature in rivers and contribute to thermal pollution, which greatly affects the river aquatic ecosystems. Understanding the temporal and spatial variation of thermal pollution caused by dams is important to prevent or mitigate its harmful effect. Assessments based on in-situ measurements are often limited in practice because of the inaccessibility of water temperature records and the scarcity of gauges along rivers. By contrast, thermal infrared remote sensing provides an alternative approach to monitor thermal pollution downstream of dams in large rivers, because it can cover a large area and observe the same zone repeatedly. In this study, Landsat Enhanced Thematic Mapper Plus (ETM+ thermal infrared imagery were applied to assess the thermal pollution caused by two dams, the Geheyan Dam and the Gaobazhou Dam, located on the Qingjiang River, a tributary of the Yangtze River downstream of the Three Gorges Reservoir in Central China. The spatial and temporal characteristics of thermal pollution were analyzed with water temperatures estimated from 54 cloud-free Landsat ETM+ scenes acquired in the period from 2000 to 2014. The results show that water temperatures downstream of both dams are much cooler than those upstream of both dams in summer, and the water temperature remains stable along the river in winter, showing evident characteristic of the thermal pollution caused by dams. The area affected by the Geheyan Dam reaches beyond 20 km along the downstream river, and that affected by the Gaobazhou Dam extends beyond the point where the Qingjiang River enters the Yangtze River. Considering the long time series and global coverage of Landsat ETM+ imagery, the proposed technique in the current study provides a promising method for globally monitoring the thermal pollution caused by dams in large rivers.

  11. Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

    Science.gov (United States)

    Shafroth, Patrick B.; Perry, Laura G; Rose, Chanoane A; Braatne, Jeffrey H

    2016-01-01

    Understanding how dams affect the shifting habitat mosaic of river bottomlands is key for protecting the many ecological functions and related goods and services that riparian forests provide and for informing approaches to riparian ecosystem restoration. We examined the downstream effects of two large dams on patterns of forest composition, structure, and dynamics within different geomorphic contexts and compared them to upstream reference conditions along the Elwha River, Washington, USA. Patterns of riparian vegetation in river segments downstream of the dams were driven largely by channel and bottomland geomorphic responses to a dramatically reduced sediment supply. The river segment upstream of both dams was the most geomorphically dynamic, whereas the segment between the dams was the least dynamic due to substantial channel armoring, and the segment downstream of both dams was intermediate due to some local sediment supply. These geomorphic differences were linked to altered characteristics of the shifting habitat mosaic, including older forest age structure and fewer young Populus balsamifera subsp. trichocarpa stands in the relatively static segment between the dams compared to more extensive early-successional forests (dominated by Alnus rubra and Salix spp.) and pioneer seedling recruitment upstream of the dams. Species composition of later-successional forest communities varied among river segments as well, with greater Pseudotsuga menziesii and Tsuga heterophylla abundance upstream of both dams, Acer spp. abundance between the dams, and P. balsamifera subsp. trichocarpa and Thuja plicata abundance below both dams. Riparian forest responses to the recent removal of the two dams on the Elwha River will depend largely on channel and geomorphic adjustments to the release, transport, and deposition of the large volume of sediment formerly stored in the reservoirs, together with changes in large wood dynamics.

  12. A Framework for Multifunctional Green Infrastructure Investment in Camden, NJ

    Directory of Open Access Journals (Sweden)

    Kate Zidar

    2017-09-01

    Full Text Available This study demonstrates a decision-support framework for planning Green Infrastructure (GI systems that maximize urban ecosystem services in Camden, NJ. Seven key ecosystem services are evaluated (urban agriculture expansion, combined sewer overflow reduction, heat island reduction, flooding reduction, capacity building/green jobs expansion, fitness expansion, and stress reduction, to produce a normalized value for each service for each drainage sub-basin within the city. Gaps in ecosystem services are then mapped and utilized to geographically prioritize different kinds of multifunctional GI. Conceptual designs are developed for four site typologies: parks, schools, vacant lots, and brownfield sites. For one demonstration site, additional analysis is presented on urban engagement, life cycle cost reduction, and new sources of funding. What results is an integrated, long-term vision where multifunctional GI systems can be readily customized to meet multiple needs within urban communities. This study provides a portable and replicable framework for leveraging the regulatory requirement to manage stormwater to meet broader urban revitalization goals, all through a decentralized network of green infrastructure assets.

  13. Estimating Water Balance Components of Lakes and Reservoirs Using Various Open Access Satellite Databases

    NARCIS (Netherlands)

    Duan, Z.

    2014-01-01

    There are millions of lakes and ten thousands of reservoirs in the world. The number of reservoirs is still increasing through the construction of large dams to meet the growing demand for water resources, hydroelectricity and economic development. Accurate information on the water balance

  14. Phenotypic plasticity in fish life-history traits in two neotropical reservoirs: Petit-Saut Reservoir in French Guiana and Brokopondo Reservoir in Suriname

    Directory of Open Access Journals (Sweden)

    Bernard de Mérona

    Full Text Available Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years and the much older Brokopondo Reservoir in Suriname (44 years. Six life-history traits in 14 fish species were studied and compared to their value in the Sinnamary River prior to the completion of Petit-Saut Reservoir. The traits analyzed were maximum length, absolute and relative length at first maturation, proportion of mature oocytes in ripe gonad, batch fecundity and mean size of mature oocytes. The results revealed a general increase of reproductive effort. All species showed a decrease in maximum length. Compared to the values observed before the dam constructions, eight species had larger oocytes and three species showed an increased batch fecundity. These observed changes suggest a trend towards a pioneer strategy. The changes observed in Petit-Saut Reservoir also seemed to apply to the 30 years older Brokopondo Reservoir suggesting that these reservoirs remain in a state of immaturity for a long time.

  15. National Dam Safety Program. Alcyon Lake Dam (NJ 00427) Delaware River Basin, Chestnut Branch-Mantua Creek, Gloucester County, New Jersey. Phase 1 Inspection Report.

    Science.gov (United States)

    1981-05-01

    froma small concreto , platform which extends out from the- culvert fas Ci,). The qate is divided into two section, and is mounted on a steel frame...se(ver al concreto fILurneS that0 e xiend fromn the, nrmcurhli me andI drain baick into the, reiser vo ir . AlIl were o-r i qi n a Iv e% qu i pped( wi

  16. National Dam Safety Program. Lake Wanda Dam (NJ00510), Hudson River Basin, Tributary to Wawayanda Creek, Sussex County, New Jersey. Phase 1 Inspection Report.

    Science.gov (United States)

    1980-03-01

    8217 7rA’Al’A𔄀 /O’ 3 4 5 $-eS 7W# 55 Af1--7;72 6 10 12 - . . . . . ... . . . . . .’ . . .. 13 l 14 15 £ F6 3I f’f . 16 A6 18 19 200 _.._. . . . .. . . . 21’ 22...191, ~ C! . .. .. C.C C C L. C . C W .C . . . .C .C . . . .C .C . . . . .C . C . C C. . C . C 4 4 . . . a CC aa acca a aa aa C C

  17. National Dam Safety Program. Seeley’s Pond Dam (NJ00368) Raritan River Basin, Blue Brook, Union County, New Jersey. Phase I Inspection Program.

    Science.gov (United States)

    1980-02-01

    Engineer District, Philadelphia Custom House, 2d & Chestnut Streets Unclassified Philadelphia, PA 19106 ISo . OECLASSIFICATION/OOWNGRADING SCHEDULE Is...57. ... 81. 49 206.0 - 1.02 3.00 81 27000 54a 75. 48. 206.0 1o02 3.20 82 27.33 50. 700 4?0 205.9 1.02 3*04 83 27.67 470 65. 47. 205.9 :.02 4*00

  18. WATER LOSS OF KOKA RESERVOIR, ETHIOPIA: COMMENTS ON

    African Journals Online (AJOL)

    to be used for Awash River simulation model. Key words/phrases: Ethiopia, Koka Reservoir water loss, leakage rate, subsurface inflow, water balance. INTRODUCTION. Koka Dam was built on Awash River, Ethiopia, in 1960 for hydropower and irrigation purposes. It is located at 8°24'N latitude and 39°05'E longitude (Fig.

  19. The Ecological effect of conveyance pipeline from Gurara reservoir ...

    African Journals Online (AJOL)

    The study focuses on the public awareness of the effect of conveyance pipeline from Gurara reservoir to lower Usman Dam on Ecological degradation in Abuja, using data from questionnaire survey of about 150 households as well as field observation. The data from the survey reveals that over 30% ecological degradations ...

  20. Determining water reservoir characteristics with global elevation data

    NARCIS (Netherlands)

    van Bemmelen, C. W T; Mann, M.; de Ridder, M.P.; Rutten, M.M.; van de Giesen, N.C.

    2016-01-01

    Quantification of human impact on water, sediment, and nutrient fluxes at the global scale demands characterization of reservoirs with an accuracy that is presently unavailable. This letter presents a new method, based on virtual dam placement, to make accurate estimations of area-volume

  1. DECREASING OF WATER TROPHY IN CASCADE SYSTEMS, ON EXAMPLE OF THE SOŁA RIVER DAM CASCADE (SOUTHERN POLAND

    Directory of Open Access Journals (Sweden)

    Ewa Jachniak

    2014-10-01

    Full Text Available In this thesis the subject of water self-purification in cascade systems of water reservoirs was engaged. The results of hydrobiological research of three dam reservoirs (Tresna, Porąbka and Czaniec, creating the Soła river dam cascade were presented. The trophic status of these reservoirs was defined on the grounds of the concentration of chlorophyll a, biomass of phytoplankton and occurrence of indicating species of planktonic algae. The results of research indicated on decreasing of water trophy in the layout from the highest into the lowest reservoir of the cascade. The average concentrations of chlorophyll a amounted appropriately 19,99 μg·dm-3, 8,74 μg·dm-3 and 4,29 μg·dm-3, instead the average biomass of phytoplankton amounted appropriately 4,1 mg·dm-3, 3,4 mg·dm-3 and 0,1 mg·dm-3. The observed species of algae confirmed occurrence of differences between reservoirs. In Tresna reservoir more species of phytoplankton indicating for eutrophy were thrived, instead in Porąbka and Czaniec reservoirs the species occurring in oligomesotrophic water thrived. Water self-purification in the Soła river dam cascade expressed decreasing of their fertility is important for water management of the region, because the Czaniec reservoir fulfill a function of water-supply reservoir.

  2. White sturgeon mitigation and restoration in the Columbia and Snake rivers upstream from Bonneville Dam, Annual Progress Report April 2006 - March 2007. Report C

    Science.gov (United States)

    Parsley, M.J.; Kofoot, P.

    2008-01-01

    Describe reproduction and early life history characteristics of white sturgeon populations in the Columbia River between Bonneville and Priest Rapids dams. Define habitat requirements for spawning and rearing white sturgeon and quantify the extent of habitat available in the Columbia River between Bonneville and Priest Rapids dams. Progress updates on young-of-the-year recruitment in Bonneville Reservoir and indices of white sturgeon spawning habitat for 2006 for McNary, John Day, The Dalles, and Bonneville dam tailrace spawning areas.

  3. Odelouca Dam Construction: Numerical Analysis

    OpenAIRE

    Brito, A.; Maranha, J. R.; Caldeira, L.

    2012-01-01

    Odelouca dam is an embankment dam, with 76 m height, recently constructed in the south of Portugal. It is zoned with a core consisting of colluvial and residual schist soil and with soil-rockfill mixtures making up the shells (weathered schist with a significant fraction of coarse sized particles). This paper presents a numerical analysis of Odelouca Dam`s construction. The material con-stants of the soil model used are determined from a comprehensive testing programme carried out in the C...

  4. Neotectonics of the Vajont dam site

    Science.gov (United States)

    Mantovani, Franco; Vita-Finzi, Claudio

    2003-08-01

    The disastrous Vajont landslide (NE Italy) of 9 October 1963 is generally thought to have occurred on an existing failure surface. Reassessment of the morphological and structural evidence suggests that movement was on a normal fault plane which had juxtaposed Cretaceous limestone and highly fractured rock debris, thus rendering the dam site unusually susceptible to massive sliding. The proposed fault is consistent in strike with the regional lineament pattern. Although movement was triggered by the combined effects of heavy rainfall and changes in reservoir level, there is circumstantial evidence that seismicity played a contributory part in mobilising the slide by increasing pore pressure at the base of the slide as well as by any associated shaking.

  5. Dams release methane even in temperate zoned

    International Nuclear Information System (INIS)

    Lemarchand, F.

    2010-01-01

    The Wohlen lake (near Bern) is a retaining dam built 90 years ago that has undergone a campaign to measure the quantity of methane released. The campaign lasted 1 year and the result was unexpected: 0.15 g/m 2 *day which one of the highest release rates in temperate zones. This result is all the more stunning since water stays only 2 days in average in the reservoir and that the drowned area is not important. In fact the river Aar that feeds the lake is loaded with organic matter coming from humane activities: agriculture and 3 sewage plants. This organic matter decays in the lake releasing methane. (A.C.)

  6. Anticipated sediment delivery to the lower Elwha River during and following dam removal: Chapter 2 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

    Science.gov (United States)

    Czuba, Christiana R.; Randle, Timothy J.; Bountry, Jennifer A.; Magirl, Christopher S.; Czuba, Jonathan A.; Curran, Christopher A.; Konrad, Christopher P.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

    2011-01-01

    During and after the planned incremental removal of two large, century-old concrete dams between 2011 and 2014, the sediment-transport regime in the lower Elwha River of western Washington will initially spike above background levels and then return to pre-dam conditions some years after complete dam removal. Measurements indicate the upper reaches of the steep-gradient Elwha River, draining the northeast section of the Olympic Mountains, carries between an estimated 120,000 and 290,000 cubic meters of sediment annually. This large load has deposited an estimated 19 million cubic meters of sediment within the two reservoirs formed by the Elwha and Glines Canyon Dams. It is anticipated that from 7 to 8 million cubic meters of this trapped sediment will mobilize and transport downstream during and after dam decommissioning, restoring the downstream sections of the sediment-starved river and nearshore marine environments. Downstream transport of sediment from the dam sites will have significant effects on channel morphology, water quality, and aquatic habitat during and after dam removal. Sediment concentrations are expected to be between 200 and 1,000 milligrams per liter during and just after dam removal and could rise to as much as 50,000 milligrams per liter during high flows. Downstream sedimentation in the river channel and flood plain will be potentially large, particularly in the lower Elwha River, an alluvial reach with a wide flood plain. Overall aggradation could be as much as one to several meters. Not all reservoir sediment, however, will be released to the river. Some material will remain on hill slopes and flood plains within the drained reservoirs in quantities that will depend on the hydrology, precipitation, and mechanics of the incising channel. Eventually, vegetation will stabilize this remaining reservoir sediment, and the overall sediment load in the restored river will return to pre-dam levels.

  7. Improved water management with the development of Snake Lake Reservoir

    International Nuclear Information System (INIS)

    Kemp, P.; Miller, D.; Webber, J.

    1998-01-01

    The $10.3 million Snake Lake Reservoir which is located south of the TransCanada Highway between Bassano and Brooks, in Alberta, was completed in 1997. It provides 19.1 million cubic meters of storage to improve the water supply for the irrigation of 29,000 hectares of agricultural land in the Eastern Irrigation District. One of challenges that engineers faced during the construction of the reservoir was the extremely soft dam foundation conditions. The resolution of this and other challenges are discussed. In addition to water storage, the reservoir also provides wildlife, recreation and aquaculture opportunities. 8 refs., 5 figs

  8. Narora reservoir, U.P. - - a potential bird sanctuary

    International Nuclear Information System (INIS)

    Rahmani, A.R.

    1981-01-01

    Narora (28deg 15'N, 78deg 23'E) in Bulandshahr district of Uttar Pradesh is the site of India's fourth atomic power plant. It lies on the main migratory route of the birds of Palaearctic region. Due to damming of the river Ganga, a huge reservoir is formed. About 120 species of birds are found in the reservoir area. Important ones are listed. The potentiality of the reservoir and adjoining marshes for development of a bird sanctuary is assessed. (M.G.B.)

  9. Effects of damming on the distribution and methylation of mercury in Wujiang River, Southwest China.

    Science.gov (United States)

    Zhao, Lei; Guo, Yanna; Meng, Bo; Yao, Heng; Feng, Xinbin

    2017-10-01

    Newly built reservoirs are regarded as sensitive ecosystem for mercury (Hg) methylation. A comprehensive study was conducted to understand the influence of damming on the distribution and methylation of Hg within a river-reservoir ecosystem in Wujiang River Basin (WRB), Southwest China. Hg species in inflow-outflow rivers of six cascade reservoirs were analyzed each month during 2006. Mean concentrations of total Hg (THg) and methylmercury (MeHg) in river water in WRB were 3.41 ± 1.98 ng L -1 and 0.15 ± 0.06 ng L -1 , respectively. THg and particulate Hg (PHg) concentrations in outflow rivers of reservoirs significantly decreased after dam construction, suggesting that a considerable amount of PHg was intercepted by way of sedimentation. However, the influence of damming on the distributions of dissolved Hg (DHg) and reactive Hg (RHg) in rivers was less pronounced. MeHg concentrations in outflow rivers of the older reservoirs significantly increased compared to inflow rivers with the maximum increasing factor of 92%, indicating the active net Hg methylation in the reservoirs. However, the difference between MeHg in inflow rivers and outflow rivers were less pronounced in the newly constructed reservoirs, indicating that these reservoirs were not active sites of Hg methylation. The construction of the cascade reservoirs resulted in the elevation of MeHg in several sections of the Wujiang River, which attributed to the net Hg methylation in reservoirs and discharge of MeHg from hypolimnion. MeHg-enriched water in outflow rivers from hypolimnetic water could be transported to downstream, posing potential threat to the aquatic food web and human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Dam Break Analysis of Embankment Dams Considering Breach Characteristics

    Directory of Open Access Journals (Sweden)

    Abolfazl Shamsaei

    2004-05-01

    Full Text Available The study of dam's break, needs the definition of various parameters such as the break cause, its type, its dimension and the duration of breach development. The precise forecast for different aspects of the breach is one of the most important factors for analyzing it in embankment dam. The characteristics of the breach and determination of their vulnerability has the most effect on the waves resulting from dam break. Investigating, about the parameters of the breach in "Silveh" earth dam have been determined using the suitable model. In Silve dam a trapezoid breach with side slope z=0.01m and the average base line b=80m was computed. The duration of the breaches development is 1.9 hour. Regarding the above results and the application of DAM Break software the consequences of the probable break of the dam was determined. The analysis of the results of water covering of the city of Piranshahr located 12km from silve dam confirms that in 3 hours the water will reach the height (level of 1425 meters.

  11. A Comparison of Flood Control Standards for Reservoir Engineering for Different Countries

    Directory of Open Access Journals (Sweden)

    Minglei Ren

    2017-02-01

    Full Text Available Across the globe, flood control standards for reservoir engineering appear different due to various deciding factors such as flood features, society, economy, culture, morality, politics, and technology resources, etc. This study introduces an in-depth comparison of flood control standards for reservoir engineering for different countries. After the comparison and analysis, it is concluded that the determination of flood control standards is related to engineering grade, dam type, dam height, and the hazard to downstream after dam-breaking, etc. Each country should adopt practical flood control standards according to the characteristics of local reservoir engineering. The constitutive flood control standards should retain certain flexibility in the basis of constraint force. This review could offer a reference for developing countries in the enactment of flood control standards for reservoir engineering.

  12. Mitigation and recovery of methane emissions from tropical hydroelectric dams

    Energy Technology Data Exchange (ETDEWEB)

    Bambace, L.A.W.; Ramos, F.M.; Lima, I.B.T.; Rosa, R.R. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos (Brazil)

    2007-06-15

    Tropical hydroelectric reservoirs generally constitute an appreciable source of methane to the atmosphere. This paper proposes simple mitigation and recovery procedures to substantially reduce atmospheric methane emissions from hydroelectric reservoirs. We aim at transforming existing methane stocks of tropical reservoirs into a clean, renewable energy source. The recovered gas methane may be pumped to large consuming centers, stocked locally and burned in gas turbines to generate electricity during high demand periods, or even purified for transport applications. Our simulations show that the use of biogenic methane may increase considerably the energy supply in countries like Brazil. As a result, it would be possible to reduce the need of additional hydroelectric dams, protecting important pristine biomes, and avoiding the resettlement of villages and indigenous reserves. (author)

  13. Aylmer Dam : past, present and future; Barrage Aylmer : passe, present et futur

    Energy Technology Data Exchange (ETDEWEB)

    Giguere, H; Lehoux, B; Toma, G [Quebec Ministere du Developpement durable, de l' Environnement et des Parcs, Quebec, PQ (Canada). Centre d' Expertise Hydrique

    2006-07-01

    The Aylmer gravity dam was built in 1953 in Weedon in Quebec's Eastern Townships. The water reservoir retained by the Aylmer Dam has a capacity of 201,928,700 cubic metres and many houses and cottages now line its shores. As such, the water level must be kept high during the summer holiday season. The initial purpose of the dam was for log transportation, the regulation of the Saint-Francois River and the production of electricity. The retention structure belongs to the Quebec government and is managed by the Centre d'Expertise Hydrique du Quebec (CEHQ). Underwater inspection of the dam in 1998 showed signs of erosion damage that required repair. Five of the dam's seven sluices were equipped with stop logs while the others had metallic floodgates. The damage was caused by the preferential use of the 2 floodgates over the years. This paper described the 3 phases for modernizing the evacuation devices of this dam. The first phase began in 2003 with the repair of the dam. The second phase involved the construction of a more modern building in 2004, and the third phase involved the replacement of wooden girders with heated metallic sluices in 2005. The modernization of this dam has reduced the time for required for water evacuation operations during all seasons and has eliminated the danger linked to de-icing techniques. 1 ref., 8 figs.

  14. Multiyear Downstream Response to Dam Removal on the White Salmon River, WA

    Science.gov (United States)

    Wilcox, A. C.; O'Connor, J. E.; Major, J. J.

    2017-12-01

    The 2011 removal of the 38 m tall Condit Dam on the White Salmon River, Washington was one of the largest dam removals to date, in terms of both dam height and sediment release. We examined the multiyear geomorphic response to this event, through 2015, including in a bedrock-confined canyon and in a less-confined, backwater-influenced pool reach near the river's mouth, to the large, rapid influx of fine reservoir sediment produced by the breach and to subsequent sediment transfer in the free-flowing White Salmon River. In the canyon reach, aggraded sediments were rapidly eroded from riffles, returning them toward pre-breach bed elevations within weeks, but pool aggradation persisted for longer. The downstream, less-confined reach transformed from a deep pool to a narrower pool-riffle channel with alternate bars; multiyear observations showed persistence of bars and of this new and distinct morphology. This downstream reach marks a rare case in post-dam removal channel response; in most dam removals, channels have rapidly reverted toward pre-removal morphology, as in the canyon reach here. Comparison of the multiyear geomorphic evolution of the White Salmon River to other recent large dam removals in the U.S. allows evaluation of the relative influences of antecedent channel morphology, post-breach hydrology, and dam removal style, as well as providing a basis for predicting responses to future dam removals.

  15. Viewpoint – Brazil’s Madeira River Dams: A Setback for Environmental Policy in Amazonian Development

    Directory of Open Access Journals (Sweden)

    Philip Martin Fearnside

    2014-02-01

    Full Text Available Decisions on hydroelectric dam construction will be critical in shaping the future of Amazonia, where planned dams would convert most tributaries into chains of reservoirs. The Santo Antônio and Jirau dams, now nearing completion on the Madeira River, have created dangerous precedents in a trend towards weakening environmental protection in Brazil. Political appointees have overruled the technical staff of the Brazilian Institute for the Environment and Renewable Natural Resources (IBAMA, which is responsible for evaluating the environmental impact study (EIA and for licensing dams. Installation licences were granted without satisfying many of the 'conditions' that had been established as prerequisites. This feature and several others of the licensing process for the Madeira River dams have now been repeated in licensing the controversial Belo Monte Dam on the Xingu River. Brazil plans to build 30 large dams in its Amazon region in a decade, and others are to be financed and built by Brazil in Peru, Bolivia, Ecuador and Guyana. These plans affect virtually all water resources in an area larger than Western Europe. The Madeira River dams indicate the need to reform the decision-making process in Brazil.

  16. Vortices in dam reservoir: A case study of Karun III dam

    Indian Academy of Sciences (India)

    Formation of vortices at power intakes is a challenging problem for hydraulic engineers. ... at a distance equal to the radius of the intake from the axis of rotation. ... demand for irrigation and drinking purposes and also power generation, Karun.

  17. Skyscraper dams in Yunnan : China's new electricity generator should step in

    Energy Technology Data Exchange (ETDEWEB)

    Ryder, G.

    2006-05-12

    The construction of a series of high-head hydroelectric power dams in China's earthquake-prone Yunnan province has raised concerns in China's scientific and environmental communities. The series of skyscraper-high dams are being built to meet Beijing's power production targets without the benefit of market discipline or effective regulatory oversight. Dam building is central to Beijing's plan for tripling the country's hydropower production by 2020. To meet that target, the State Council granted exclusive development rights to Hydrolancang, the Yunnan Huadian Nu River Hydropower Development Company and the Three Gorges Corporation. The Hydrolancang company is building 2 of the world's tallest and most controversial hydro dams on the Lancang River. When completed in 2012, Xiaowan will be the world's tallest arch dam at 292 metres high. Another dam, the 254 metre high Nuozhadu dam is expected to start generating power in 2017. In addition, there are plans for 13 other high dams along the Nu River, one of only 2 major rivers in China that remains free-flowing. This document expressed that China's new electricity regulator should initiate a full-cost review of state dam-building in the earthquake-prone province. It was argued that as state-owned power companies, the dam builders are not market-driven and are shielded from many of the financial risks and environmental liabilities associated with large dams. The author argued that China's electricity regulator should examine the dam builders' projects costs and profits and review the economic implications of the hydro policy for China's power consumers. It was also suggested that the country's modernization goals for the power industry should be reviewed. The immediate concerns are ecological damage and the frequency with which Yunnan province is hit by earthquakes, rock falls and landslides. Experts caution that the extra weight of the high dams and reservoirs

  18. Favorable fragmentation: river reservoirs can impede downstream expansion of riparian weeds.

    Science.gov (United States)

    Rood, Stewart B; Braatne, Jeffrey H; Goater, Lori A

    2010-09-01

    River valleys represent biologically rich corridors characterized by natural disturbances that create moist and barren sites suitable for colonization by native riparian plants, and also by weeds. Dams and reservoirs interrupt the longitudinal corridors and we hypothesized that this could restrict downstream weed expansion. To consider this "reservoir impediment" hypothesis we assessed the occurrences and abundances of weeds along a 315-km river valley corridor that commenced with an unimpounded reach of the Snake River and extended through Brownlee, Oxbow, and Hells Canyon reservoirs and dams, and downstream along the Snake River. Sampling along 206 belt transects with 3610 quadrats revealed 16 noxious and four invasive weed species. Ten weeds were upland plants, with Canada thistle (Cirsium arvense) restricted to the upstream reaches, where field morning glory (Convolvulus arvensis) was also more common. In contrast, St. John's wort (Hypericum perforatum) was more abundant below the dams, and medusahead wildrye (Taeniatherum caput-medusae) occurred primarily along the reservoirs. All seven riparian species were abundant in the upstream zones but sparse or absent below the dams. This pattern was observed for the facultative riparian species, poison hemlock (Conium maculatum) and perennial pepperweed (Lepidium latifolium), the obligate riparian, yellow nut sedge (Cyperus esculentus), the invasive perennial, reed canary grass (Phalaris arundinacea), and three invasive riparian trees, Russian olive (Elaeagnus angustifolia), false indigo (Amorpha fruticosa), and tamarisk (Tamarix spp.). The hydrophyte purple loosestrife (Lythrum salicaria) was also restricted to the upstream zone. These longitudinal patterns indicate that the reservoirs have impeded the downstream expansion of riparian weeds, and this may especially result from the repetitive draw-down and refilling of Brownlee Reservoir that imposes a lethal combination of drought and flood stress. The dams and

  19. The mathematics of dam safety

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, R. [Osterreichische Gesellschaft fuer Geomechanik, Salzburg (Austria)

    1997-05-01

    The safety of a dam is determined by its design, construction and supervision during operation. High arch dam failures have dropped dramatically since the early part of this century. An essential part of the success story relates to improved measurement techniques that can detect earlier unexpected behaviour that may lead to failure. (UK)

  20. Evaluatie Dam tot Damloop 2014

    NARCIS (Netherlands)

    Deutekom-Baart de la Faille, Marije

    In het weekend van 20 en 21 september 2014 vond de 30ste editie van de Dam tot Damloop plaats. Onderzoekers van de Hogeschool van Amsterdam en Hogeschool Inholland hebben bij de Dam tot Damloop een evaluatieonderzoek uitgevoerd met als doel het vinden van aanknopingspunten voor het structureel

  1. After Three Gorges Dam: What have we learned?

    Science.gov (United States)

    Natali, J.; Williams, P.; Wong, R.; Kondolf, G. M.

    2013-12-01

    China is at a critical point in its development path. By investing heavily in large-scale infrastructure, the rewards of economic growth weigh against long-term environmental and social costs. The construction of Three Gorges Dam, the world's largest hydroelectric project, began in 1994. Between 2002 and 2010, its 660 kilometer reservoir filled behind a 181 meter dam, displacing at least 1.4 million people and transforming Asia's longest river (the Yangtze) while generating nearly 100 billion kWh/yr of electricity -- 2.85% of China's current electric power usage. As the mega-project progenitor in a cascade of planned dams, the Three Gorges Dam emerges as a test case for how China will plan, execute and mitigate its development pathway and the transformation of its environment. Post-Project Assessments (PPA) provide a systematic, scientific method for improving the practice of environmental management - particularly as they apply to human intervention in river systems. In 2012, the Department of Landscape Architecture and Environmental Planning at University of California, Berkeley organized a symposium-based PPA for the Three Gorges Dam on the Yangtze River. Prior to this symposium, the twelve invited Chinese scientists, engineers and economists with recent research on Three Gorges Dam had not had the opportunity to present their evaluations together in an open, public forum. With a 50-year planning horizon, the symposium's five sessions centered on impacts on flows, geomorphology, geologic hazards, the environment and socioeconomic effects. Three Gorges' project goals focused on flood control, hydropower and improved navigation. According to expert research, major changes in sediment budget and flow regime from reservoir operation have significantly reduced sediment discharge into the downstream river and estuary, initiating a series of geomorphic changes with ecological and social impacts. While the dam reduces high flow stages from floods originating above the

  2. Status and Habitat Requirements of White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1988-1989 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nigro, Anthony A. (Oregon Dept. of Fish and Wildlife, Portland, OR (USA))

    1989-09-01

    We report on our progress from April 1988 through March 1989 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. Highlights of results of our work in the Dalles and Bonneville reservoirs are: using setlines, we caught 1,586 sturgeon in The Dalles Reservoir and 484 sturgeon in Bonneville Reservoir in 1988. Fork length of fish caught ranged from 34 cm to 274 cm. Of the fish caught we marked 1,248 in The Dalles Reservoir and 341 in Bonneville Reservoir. Of the fish marked in 1988, we recaptured 82 in The Dalles Reservoir and none in Bonneville Reservoir. We recaptured 89 fish marked in 1987 in The Dalles Reservoir. Anglers recaptured 35 fish marked in 1988 and 16 fish marked in 1987 in The Dalles Reservoir. Anglers recaptured 2 sturgeon marked in 1988 in Bonneville Reservoir. Individual papers were processed separately for the data base.

  3. Developing a Water Quality Index (WQI) for an Irrigation Dam.

    Science.gov (United States)

    De La Mora-Orozco, Celia; Flores-Lopez, Hugo; Rubio-Arias, Hector; Chavez-Duran, Alvaro; Ochoa-Rivero, Jesus

    2017-04-29

    Pollution levels have been increasing in water ecosystems worldwide. A water quality index (WQI) is an available tool to approximate the quality of water and facilitate the work of decision-makers by grouping and analyzing numerous parameters with a single numerical classification system. The objective of this study was to develop a WQI for a dam used for irrigation of about 5000 ha of agricultural land. The dam, La Vega, is located in Teuchitlan, Jalisco, Mexico. Seven sites were selected for water sampling and samples were collected in March, June, July, September, and December 2014 in an initial effort to develop a WQI for the dam. The WQI methodology, which was recommended by the Mexican National Water Commission (CNA), was used. The parameters employed to calculate the WQI were pH, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), total hardness (TH), alkalinity (Alk), total phosphorous (TP), Cl - , NO₃, SO₄, Ca, Mg, K, B, As, Cu, and Zn. No significant differences in WQI values were found among the seven sampling sites along the dam. However, seasonal differences in WQI were noted. In March and June, water quality was categorized as poor. By July and September, water quality was classified as medium to good. Quality then decreased, and by December water quality was classified as medium to poor. In conclusion, water treatment must be applied before waters from La Vega dam reservoir can be used for irrigation or other purposes. It is recommended that the water quality at La Vega dam is continually monitored for several years in order to confirm the findings of this short-term study.

  4. Seismic resistant design of a nuclear category I earth dam

    International Nuclear Information System (INIS)

    Vaidya, N.R.; Ries, E.R.; Kissenpfennig, J.F.

    1975-01-01

    An integral part of many nuclear power plants is the ultimate heat sink (UHS); the purpose of which is to retain and deliver a supply of service water to the plant when water from the primary circulating water system is not available. The earth dam described herein is designed to retain the reservoir for the UHS of a nuclear power plant in Southern Europe. The usual pseudo-static analysis is only as good as the estimate for the seismic coefficient used to compute an equivalent horizontal static force on a potential sliding mass. In view of the earth dam considered herein, a more accurate computation of the seismic coefficients is to be made. A two-dimensional dynamic finite element analysis is made to predict the response of the earth dam to a Safe Shutdown Earthquake excitation which is in the form of a time history of accelerations appropriately deconvoluted from the surficial time history and applied at the base of the model. The material properties such as shear modulus and damping are adjusted to be compatible with the level of strain obtained. Thus, non-linear behavior of soil is considered in the analysis and a more realistic response is predicted. Acceleration and stress are determined throughout the dam and are used to compute a seismic coefficient for a pseudo-static stability analysis and the dynamic strength to stress ratios at several points in the body of the dam. The need to design the dam to resist a progressive erosion accident resulting from postulated concentrated leaks is discussed. This may be accomplished by providing a wide, well graded core protected by wide transition cores also heavily compacted

  5. Hydrological Analysis for Inflow Forecasting into Temengor Dam

    Science.gov (United States)

    Najid, MI; Sidek, LM; Hidayah, B.; Roseli, ZA

    2016-03-01

    These days, natural disaster such as flood is the main concern for hydrologists. One of solutions in understanding the reason of flood is by prediction of the event sooner than normal occurrence. One of the criteria is lead time or travel time that is important in the study of fresh waters and flood events. Therefore, estimation of lead or travel time for flood event can be beneficial primary information. The objective of this study is to estimate the lead time or travel time for outlet of Temengor dam in Malaysia. Tenaga Nasional Berhad (TNB) Sungai Perak dam operation has the main contribution on decision support for early water released and flood warning to authorities and locals resident for in the down streams area. For this study, hydrological analysis carried out will help to determine which years that give more rainfall contribution into the reservoir. Rainfall contribution of reservoir help to understanding rainfall distribution and peak discharge on that period. It also help for calibration of forecasting model system for better accuracy of flood hydrograph. There may be various methods to determine the rainfall contribution of catchment. The result has shown that, the rainfall contribution for Temengor catchment, is more on November in each year which is the monsoon season in Malaysia. TNB dam operational decision support systems can prepare and be more aware at this time for flood control and flood mitigation.

  6. Damming evidence : Canada and the World Commission on Dams

    Energy Technology Data Exchange (ETDEWEB)

    Vert, P.; Parkinson, B.

    2003-06-01

    Large hydroelectric projects have been met with strong resistance from affected communities, particularly indigenous groups who have been displaced from their flooded communities following the damming of a river. The World Commission on Dams (WCD) was formed in 1998 to review the effectiveness of large dams and develop internationally acceptable guidelines and standards for large dams or hydro energy projects. The Canadian government, through the Canadian International Development Agency, was one of many governments to fund the WCD. However, the authors argue that despite the financial support, the Canadian government was absent from any effort to follow-up on the recommendations of the WCD. The seven strategic priorities in the decision making process include: (1) gaining public acceptance, (2) comprehensive option assessment of water, energy, food and development needs, (3) addressing existing dams to improve the benefits that can be derived from them, (4) sustaining livelihoods, (5) recognizing the entitlements and sharing benefits, (6) ensuring compliance, and (7) sharing rivers for peace, development and security. This report offers a means to assess planned or existing dams and presents a set of guidelines for good practices linked to the seven strategic priorities. Ten case studies from around the world were presented, including the Three Gorges Dam in China. 154 refs., 3 figs., 3 appendices.

  7. Ambient modal testing of a double-arch dam: the experimental campaign and model updating

    International Nuclear Information System (INIS)

    García-Palacios, Jaime H.; Soria, José M.; Díaz, Iván M.; Tirado-Andrés, Francisco

    2016-01-01

    A finite element model updating of a double-curvature-arch dam (La Tajera, Spain) is carried out hereof using the modal parameters obtained from an operational modal analysis. That is, the system modal dampings, natural frequencies and mode shapes have been identified using output-only identification techniques under environmental loads (wind, vehicles). A finite element model of the dam-reservoir-foundation system was initially created. Then, a testing campaing was then carried out from the most significant test points using high-sensitivity accelerometers wirelessly synchronized. Afterwards, the model updating of the initial model was done using a Monte Carlo based approach in order to match it to the recorded dynamic behaviour. The updated model may be used within a structural health monitoring system for damage detection or, for instance, for the analysis of the seismic response of the arch dam- reservoir-foundation coupled system. (paper)

  8. Application of Electrical Resistivity Tomography Technique for Characterizing Leakage Problem in Abu Baara Earth Dam, Syria

    Directory of Open Access Journals (Sweden)

    Walid Al-Fares

    2014-01-01

    Full Text Available Electrical Resistivity Tomography (ERT survey was carried out at Abu Baara earth dam in northwestern Syria, in order to delineate potential pathways of leakage occurring through the subsurface structure close to the dam body. The survey was performed along two straight measuring profiles of 715 and 430 m length in up- and downstream sides of the dam’s embankment. The analysis of the inverted ERT sections revealed the presence of fractured and karstified limestone rocks which constitute the shallow bedrock of the dam reservoir. Several subsurface structural anomalies were identified within the fractured bedrock, most of which are associated with probable karstic cavities, voids, and discontinuity features developed within the carbonates rocks. Moreover, results also showed the occurrence of a distinguished subsiding structure coinciding with main valley course. Accordingly, it is believed that the bedrock and the other detected features are the main potential causes of water leakage from the dam’s reservoir.

  9. Applying the World Water and Agriculture Model to Filling Scenarios for the Grand Ethiopian Renaissance Dam

    Energy Technology Data Exchange (ETDEWEB)

    Villa, Daniel L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tidwell, Vincent C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Passell, Howard D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    The World Water and Agriculture Model has been used to simulate water, hydropower, and food sector effects in Egypt, Sudan, and Ethiopia during the filling of the Grand Ethiopian Renaissance Dam reservoir. This unique capability allows tradeoffs to be made between filling policies for the Grand Ethiopian Renaissance Dam reservoir. This Nile River Basin study is presented to illustrate the capacity to use the World Water and Agriculture Model to simulate regional food security issues while keeping a global perspective. The study uses runoff data from the Intergovernmental Panel for Climate Change Coupled Model Inter-comparison Project Phase 5 and information from the literature in order to establish a reasonable set of hydrological initial conditions. Gross Domestic Product and population growth are modelled exogenously based on a composite projection of United Nations and World Bank data. The effects of the Grand Ethiopian Renaissance Dam under various percentages of water withheld are presented.

  10. Use of isotopes and geophysical techniques in studying dam leakage-case of the Afamia dams Syria

    International Nuclear Information System (INIS)

    Kattan, Z.; Naser, R.; Al-Fares, W.; Kadkoy, N.; Sbenati, M.R.; Al-Hilal, M.; Sleman, I.; Al-Ali, A.

    2011-08-01

    Different techniques such as: hydrochemistry, environmental isotopes, radon and geophysical surveys have been applied all together in investigating the water leakages from the Afamia (A, B and C) dams during the period 2006-2008. Groundwater movement in this area shows the existence of two major discharge cones or sinks in the vicinity of B and C reservoirs. This movement suggests a probable vertical leaking and interconnection between the shallow Neogene aquifer and the deeper Karstified water bearing system of the Upper Cretaceous. Spatial distribution patterns of major ions in the groundwater provided comprehensive arguments for the existence of an active dissolution zone of calcareous rocks at a depth of about 45 m below the land surface, facilitating hence the vertical penetration of stored surface water towards the Cretaceous aquifer. The remarkable contrasts in stable isotope compositions between the depleted and highly enriched waters nearby the B reservoir provide another support for water leaks by vertical penetration beneath or very close to the B dam body. The high radon values in the soils, linearly distributed along some tectonic lineaments, may indicate the usefulness of radon method for tracing and mapping unknown faults. Application of some selected geophysical methods (electromagnetic survey, vertical geoelectric sounding and tomography plates) revealed the presence of alternating lithological heterogeneity between permeable and impermeable layers, which may lead to subhorizontal infiltration through the geological formations of the basin. Vertical leakage which could take place in certain locations via existing faults and karst and fractures that hit the main valley may pass through the dam lake. This structure is most likely causing hydraulic connections between the superficial Neogene deposits and the underlying Cretaceous fractured and permeable carbonates rocks. The presence of clayey and silty zones, mostly of high electrical conductivity

  11. Construção de cenários por análises temporais e métricas espaciais em área sob influência de reservatórios de hidrelétricas. Construction of scenarios by time series analysis and space metrics in region under the influence of hydroelectric dams reservoirs.

    Directory of Open Access Journals (Sweden)

    Rozely Ferreira dos SANTOS

    2008-12-01

    themaps and the change spatial indexes with historicalinformation and interviews with the localleaderships. The study area have five cities thatborder the Jupiá, Ilha Solteira and Três Irmãosreservoirs (SP, BR. These reservoirs, admittedly,changed the regional landscape. The indexes andthe metrics were linked with the historicalinformation, allowing debates of cultural factors,land local conditions, political actions andstrategies adopted to the region. It was verified thatthe deployment of the dams had a great influenceon the region dynamics, mainly for the manpowerabsorption capacity, reducing the labor in the farmsand the renting land. However, other factors,as bankruptcy of agricultural companies andimplantation of cold storage rooms in theneighborhoods, had contributed for the exchangeof agricultural areas to pastures. The leadershipshave conscience of the changes in the region andthey consider that is not good, because there wasnot development in the region.

  12. Derivation of Operation Rule for Ilisu Dam

    Directory of Open Access Journals (Sweden)

    Ahmed Abdul-Sahib Mohammed Ali

    2018-06-01

    Full Text Available Tigris River water that comes from Turkey represents the main water resource of this river in Iraq. The expansion in water river implementations has formed a source of trouble for the workers in the water resources management field in Iraqi. Unfortunately, there is no agreement between Iraq and Turkey till now to share the water of this international river. Consequently, the optimal operation of water resources systems, particularly a multi-objective, multi-reservoir, is of the most necessity at the present time. In this research two approaches, were used the dynamic programming (DP approach and simulation model to find the optimal monthly operation of Ilisu Dam (from an Iraqi point of view through a computer program (in Q. Basic language to find the optimum monthly release and storage by adopting an objective function that minimizes the release and storage losses (penalty. The historical inflow data of 588 months from (Oct. 1961 to Sep. 2009 formed the input data to the optimization models. Storage rule curves for the reservoir at (lower, mean, upper of (10%, 50%, and 90%, respectively, were found according to the results of the optimized operation. A simulation model was developed to operate the system using these rule curves.

  13. How many more dams in the Amazon?

    International Nuclear Information System (INIS)

    Tundisi, J.G.; Goldemberg, J.; Matsumura-Tundisi, T.; Saraiva, A.C.F.

    2014-01-01

    The Amazon watershed harbors a megadiversity of terrestrial and aquatic plants and animals. Mechanisms that sustain this biodiversity are the water level fluctuations the fluvial dynamics and the intense gene flux due to permanent integration of climatological, geomorphological and biological components of the system. The construction of hydroelectric reservoirs to support economic development of Brazil and other countries that share the Amazon basin will interfere with the ecological dynamics of this ecosystem changing the hydrological, hydrosocial and fundamental processes. Furthermore the construction of Andean reservoirs can disrupt the connectivity with the lower Amazon ecosystem. Principles of ecohydrologies, ecological engineering and preservation of key river basins, have to be applied in order to optimize energy production and promote conservation practices. Long term planning and integration of countries that share the Amazon basin is a strategic decision to control and develop the hydropower exploitation in the region. - Highlights: • The Amazon basin is an ecosystem of megadiversity. • The demand for energy threatens this ecosystem. • Climate, water, forests and floodplain interacts in the Amazon basin. • Dams in the Amazon basin will impact the hydrological and biological systems. • Ecohydrological principles and ecological engineering technology are necessary

  14. An integrated approach to dam safety evaluation. A case study: Upper Lake Falls Dam, Nova Scotia, Canada

    International Nuclear Information System (INIS)

    Pelletier, P.M.; Rattue, D.A.; Brown, E.R.

    1990-01-01

    Upper Lake Falls Dam is located in southwestern Nova Scotia. It is the uppermost hydroelectric development in a series of six developments on the Mersey River. The total capacity of the Mersey River system is 42 MW. The reservoir of Upper Lake Falls, Lake Rossignol, is the largest in Nova Scotia with a total area of 66 square miles and a gross storage of 800,000 acre-feet. An overview is presented of the hydrologic and hydraulic investigations carried out for the dam, which is classified as having high hazard potential because of permanent village and urban developments located downstream. The general methodology adopted in the study consisted of the following: gathering and verifying all meteorologic and hydrologic data; evaluating the Probable Maximum Precipitation (PMP) assumed to occur over the basin, and of the antecedent conditions prior to the PMP; calibrating a watershed model on flood events generated by rainfall, and by a combination of snowmelt and rainfall, and verifying the model using additional hydrologic events; deriving the Probable Maximum Flood (PMF) using the PMP results simulated on the calibrated watershed model; hydrodynamic routing of the flood hydrograph through all the developments; dambreak analysis, following sequential or independent failures; and flood inundation mapping. Details are given of safety analysis of the earthfill and concrete dam structures, reservoir management and cost-benefit analyses. 7 refs., 8 figs., 1 tab

  15. Olympic Dam Operations

    International Nuclear Information System (INIS)

    Crew, R.J.

    1992-01-01

    The Olympic Dam copper-uranium-gold-silver deposit in South Australia was discovered in 1975. The Mine is located 520 kilometres NNW of Adelaide, in South Australia. Following a six year period of intensive investigation and assessment of all the aspects required for the development of the deposit, the Joint Venturers decided in December, 1985, to proceed with the project. Milling of ore commenced in June 1988 and final products are cathode copper, uranium ore concentrate (yellow cake), and refined gold and silver. Anticipated production, from treating approximately 1.5 million tonnes of ore, in normal production years, is expected to be 45,000 tonnes of copper, 1,600 tonnes of yellow cake (1350 tonnes of Uranium), 25,000 ounces of gold and 500,000 ounces of silver. (orig./HP) [de

  16. Rehabilitation at Olympic Dam

    International Nuclear Information System (INIS)

    Chandler, W.P.; Middleton, B.A.

    1986-01-01

    Rehabilitation work on areas denuded of vegetation during the exploration phase of the Olympic Dam project was used to test various methods for regeneration of vegetation cover in the arid zone. The test work carried out on drill pads and access tracks has indicated that, with adequate site preparation, natural regeneration is the most economical and effective method to ensure post-operational stability of the affected land-forms. An on-going monitoring regime, utilising a computer data base, has been set up to allow year-to-year comparison of rehabilitation effectiveness. The database also provides a catalogue of initial colonising plants and a measure of variations in species diversity with time

  17. A prediction of Power Duration Curve from the Optimal Operation of the Multi Reservoirs System

    Directory of Open Access Journals (Sweden)

    Abdul Wahab Younis

    2013-04-01

    Full Text Available  This study aims of predication Power Duration Curves(PDC resulting from the optimal operation of the multi reservoirs system which comprises the reservoirs of Bakhma dam,Dokan dam and Makhool dam for the division of years over 30 years.Discrete Differential Dynamic Programming(DDDP has been employed to find the optimal operation of the said reservoirs.    PDC representing the relationship between the generated hydroelectric power and percentage of operation time equaled or exceeded . The importance of these curves lies in knowing the volume of electric power available for that percentage of operation time. The results have shown that the sum of yearly hydroelectric power for average Release and for the single operation was 5410,1604,2929(Mwfor the reservoirs of Bakhma, Dokan, Makhool dams, which resulted from the application of independent DDDP technology. Also, the hydroelectric power whose generation can be guranteed for 90% of the time is 344.91,107.7,188.15 (Mw for the single operation and 309.1,134.08,140.7 (Mw for the operation as a one system for the reservoirs of Bakhma, Dokan, and Makhool dams respectively.

  18. Deformation performance of Waba Dam

    Energy Technology Data Exchange (ETDEWEB)

    Salloum, T.; Bhardwaj, V.; Hassan, P. [Ontario Power Generation, Niagara-on-the-Lake, ON (Canada); Cragg, C. [Cragg Consulting Services, Toronto, ON (Canada)

    2009-07-01

    This paper described the performance of the Waba Dam which is being monitored as part of Ontario Power Generation's Dam Safety Program. It described the deformations that have been observed in this 3600 ft long earthfill dam which lies on marine clay in eastern Ontario. An extensive instrumentation program, including foundation settlement gauges, surface monuments, slope inclinometers, load cells and piezometers has been in effect since the construction of the dam in 1975. Significant settlement has occurred at Waba Dam since its construction. Wide berms were provided upstream and downstream beyond the slopes of the main fill to ensure stability of the dyke on the soft clay foundation and the crest elevations were designed to allow for the expected settlement in the foundation which would be overstressed by the dam loading. Based on current settlements, future settlements are predicted based on Asaoka's method. Inclinometer measurements have shown a foundation lateral spreading of 12 in. The lateral versus vertical deformations were found to be comparable to well behaving embankments reported in the literature. These analyses indicate that Waba Dam is performing well and should continue to perform well into the future. 8 refs., 1 tab., 14 figs.

  19. Public safety around dams guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, T [Canadian Dam Association, Edmonton, AB (Canada)

    2010-07-01

    This presentation discussed Canadian and international initiatives for improving dam safety and described some of the drivers for the development of new Canadian Dam Association (CDA) public safety guidelines for dams. The CDA guidelines were divided into the following 3 principal sections: (1) managed system elements, (2) risk assessment and management, and (3) technical bulletins. Public and media responses to the drownings have called for improved safety guidelines. While the public remains unaware of the hazards of dams, public interaction with dams is increasing as a result of interest in extreme sports and perceived rights of access. Guidelines are needed for dam owners in order to provide due diligence. Various organizations in Canada are preparing technical and public safety dam guidelines. CDA guidelines have also been prepared for signage, booms and buoys, and audible and visual alerts bulletins. Working groups are also discussing recommended practices for spill procedures, spillways and the role of professional engineers in ensuring public safety. Methods of assessing risk were also reviewed. Managed system elements for risk assessment and public interactions were also discussed, and stepped control measures were presented. tabs., figs.

  20. Reservoir safety, politics and conflict resolution : a British experience

    International Nuclear Information System (INIS)

    Clark, C.

    1998-01-01

    The flooding problem in southwest England, in particular at Somerset, Bruton, was discussed. Recent research has shown that the reservoir spillways in the area may have been underdesigned. A study was conducted in the late 1970s of the local rainfall data in order to determine whether the Bruton area is subject to an increase in severe rainfall and to determine the design of the dam. The probable maximum flood was calculated using the flood studies report method and was found to be 240 m 3 /s. The spillway was designed accordingly and the dam was constructed in 1984. Later, the probable maximum flood was recalculated using different assumptions and the new value obtained was 360 m 3 /s, an increase of 50 per cent over the original value. A subsequent report by a consulting engineering firm pointed out that some overtopping of the dam crest would have to take place and that the integrity of the dam would have to be maintained by the cover of the grass present. This, and other examples illustrate that reservoir design is not always the result of scientific research designed to prevent future reservoir failures, but that it is driven by political considerations, evolving in response to failures of existing structures. The situation remains unresolved to date, due to hesitation on the part of the Environment Agency, the Institute of Hydrology, and the Department of Environment and Transport to discuss and consider the conflicting results of the new research. 19 refs

  1. History of dams at the Department of Energy's Savannah River Site, Aiken, South Carolina

    International Nuclear Information System (INIS)

    Jones, M.P.; Wilson, C.B.

    1995-01-01

    Since the production of nuclear material at SRS for weapons required large quantities of cooling water, a series of canals, dikes, and dams were constructed to provide conveyance systems and reservoirs. This paper presents a brief overview of the history of the construction of the dams and dikes. Attention is given to the use of asphaltic concrete for 30 years (and its maintenance and repair) to line the banks of dikes and the upstream slopes of dams to prevent erosion and possible failure. The ability of asphaltic concrete in preventing dam/dike failure was proven. Benefits and drawbacks to the use of this material are discussed based on the extensive experience at SRS

  2. Natural and artificial radioactivity assessment of dam lakes sediments in Coruh River, Turkey

    International Nuclear Information System (INIS)

    Yasar Kobya; Sabit Korcak; Cafer Mert Yesilkanat

    2015-01-01

    In the sediment samples collected from 3 different dam reservoirs and 10 different stations on Coruh River, U-238, Th-232, K-40 and Cs-137 activity concentration levels were measured using high-resolution gamma-ray spectrometry. The mean concentrations of U-238, Th-232, K-40 and Cs-137 were found to be 15.8, 13.9, 551.5 and 18.1 Bq/kg in Deriner Dam Lake, 3.7, 12.5, 473.8 and 6.8 Bq/kg in Borcka Dam Lake, 14.4, 30.0, 491.7 and 18.2 Bq/kg in Muratli Dam Lake, respectively. Estimation calculations were made for the non-sampling zones by using Kriging method. Furthermore, results were compared with the similar studies done in different countries. (author)

  3. Technique and the scheme of engineering-seismometric supervision over seismic events on large dams

    Energy Technology Data Exchange (ETDEWEB)

    Karapetyan, S.; Babayan, T.; Mkrtchyan, G. [National Academy of Sciences of the Republic of Armenia (Armenia). Inst. of Geophysics and Engineering Seismology

    2004-07-01

    A network of engineering-seismometric monitoring stations have been installed at the Tavshout dam in a seismically active region of Armenia. The 37 meter high embankment dam consists of gravel-pebbles with a core of sandy clay. Recent earthquakes have presented a direct hazard for the dam and its water reservoir. In order to determine the degree of seismic hazard and prevention, it is necessary to study the interaction between the ground and the foundation of the dam. The seismometers were fixed at three points both on the foundation and the ground to obtain information on the whole route of seismic waves and to define the geology based amplification factors using empirical equations. The system of engineering-seismometric observations included a network of seismometric instruments, communications and a recording complex. 4 refs., 14 figs.

  4. Estimating accumulation rates and physical properties of sediment behind a dam: Englebright Lake, Yuba River, northern California

    Science.gov (United States)

    Snyder, Noah P.; Rubin, David M.; Alpers, Charles N.; Childs, Jonathan R.; Curtis, Jennifer A.; Flint, Lorraine E.; Wright, Scott A.

    2004-01-01

    Studies of reservoir sedimentation are vital to understanding scientific and management issues related to watershed sediment budgets, depositional processes, reservoir operations, and dam decommissioning. Here we quantify the mass, organic content, and grain-size distribution of a reservoir deposit in northern California by two methods of extrapolating measurements of sediment physical properties from cores to the entire volume of impounded material. Englebright Dam, completed in 1940, is located on the Yuba River in the Sierra Nevada foothills. A research program is underway to assess the feasibility of introducing wild anadromous fish species to the river upstream of the dam. Possible management scenarios include removing or lowering the dam, which could cause downstream transport of stored sediment. In 2001 the volume of sediments deposited behind Englebright Dam occupied 25.5% of the original reservoir capacity. The physical properties of this deposit were calculated using data from a coring campaign that sampled the entire reservoir sediment thickness (6–32 m) at six locations in the downstream ∼3/4 of the reservoir. As a result, the sediment in the downstream part of the reservoir is well characterized, but in the coarse, upstream part of the reservoir, only surficial sediments were sampled, so calculations there are more uncertain. Extrapolation from one-dimensional vertical sections of sediment sampled in cores to entire three-dimensional volumes of the reservoir deposit is accomplished via two methods, using assumptions of variable and constant layer thickness. Overall, the two extrapolation methods yield nearly identical estimates of the mass of the reservoir deposit of ∼26 × 106 metric tons (t) of material, of which 64.7–68.5% is sand and gravel. Over the 61 year reservoir history this corresponds to a maximum basin-wide sediment yield of ∼340 t/km2/yr, assuming no contribution from upstream parts of the watershed impounded by other dams. The

  5. Synthesis of common management concerns associated with dam removal

    Science.gov (United States)

    Tullos, Desiree D.; Collins, Mathias J.; Bellmore, J. Ryan; Bountry, Jennifer A.; Connolly, Patrick J.; Shafroth, Patrick B.; Wilcox, Andrew C.

    2016-01-01

    Managers make decisions regarding if and how to remove dams in spite of uncertainty surrounding physical and ecological responses, and stakeholders often raise concerns about certain negative effects, regardless of whether or not these concerns are warranted at a particular site. We used a dam-removal science database supplemented with other information sources to explore seven frequently-raised concerns, herein Common Management Concerns (CMCs). We investigate the occurrence of these concerns and the contributing biophysical controls. The CMCs addressed are: degree and rate of reservoir sediment erosion, excessive channel incision upstream of reservoirs, downstream sediment aggradation, elevated downstream turbidity, drawdown impacts on local water infrastructure, colonization of reservoir sediments by non-native plants, and expansion of invasive fish. Biophysical controls emerged for some of the concerns, providing managers with information to assess whether a given concern is likely to occur at a site. To fully assess CMC risk, managers should concurrently evaluate site conditions and identify the ecosystem or human uses that will be negatively affected if the biophysical phenomenon producing the CMC occurs. We show how many CMCs have one or more controls in common, facilitating the identification of multiple risks at a site, and demonstrate why CMC risks should be considered in the context of other factors like natural watershed variability and disturbance history.

  6. Proceedings of the Canadian Dam Association's 2006 annual conference: dams: past, present and future

    International Nuclear Information System (INIS)

    2006-01-01

    This conference addressed particular technical challenges regarding the operation of dams with particular focus on best practices for improving dam management and safety. It featured 4 workshops and a technical program led by experts on dams and tailings facilities that addressed topics such as dam construction, design and rehabilitation; dam management in a hydrological uncertainty context; monitoring, instrumentation and maintenance; dam behaviour; dam safety, dam failure and practical approaches to emergency preparedness planning for dam owners; historical aspects and environmental issues and conflicting water use. Recent developments in dam construction were reviewed along with discharge and debris management, tailings dam issues, asset management, seismic issues, public safety, seepage monitoring, flow control, dam rehabilitation, concrete testing, hydrotechnical issues, risk assessment methodology, and dam safety guidelines for extreme flood analyses and their applications. All 80 presentations from this conference have been catalogued separately for inclusion in this database. refs., tabs., figs

  7. Climate change impact on operation of dams and hydroelectricity generation in the Northeastern United States

    Science.gov (United States)

    Ehsani, N.; Vorosmarty, C. J.; Fekete, B. M.

    2016-12-01

    We are using a large-scale, high-resolution, fully integrated hydrological/reservoir/hydroelectricity model to investigate the impact of climate change on the operation of 11037 dams and generation of electricity from 375 hydroelectric power plants in the Northeastern United States. Moreover, we estimate the hydropower potential of the region by energizing the existing non-powered dams and then studying the impact of climate change on the hydropower potential. We show that climate change increases the impact of dams on the hydrology of the region. Warmer temperatures produce shorter frozen periods, earlier snowmelt and elevated evapotranspiration rates, which when combined with changes in precipitation, are projected to increase water availability in winter but reduce it during summer. As a result, the water that is stored by dams will be more than ever a necessary part of the routine water systems operations to compensate for these seasonal imbalances. The function of dams as emergency water storage for creating drought resiliency will mostly diminish in the future. Building more dams to cope with the local impacts of climate change on water resources and to offset the increased drought vulnerability may thus be inevitable. Annual hydroelectricity generation in the region is 41 Twh. Our estimate of the annual hydropower potential of non-powered dams adds up to 350 Twh. Climate change may reduce hydropower potential from non-powered dams by up to 13% and reduce current hydroelectricity generation by up to 8% annually. Hydroelectricity generation and hydropower potential may increase in winter months and decline in months of summer and fall. These changes call for recalibration of dam operations and may raise conflict of interests in multipurpose dams.

  8. National Dam Inspection Program. Ingham Creek (Aquetong Lake) Dam (NDI ID PA 00224, PA DER 9-49) Delaware River Basin, Ingham Creek, Pennsylvania. Phase I Inspection Report,

    Science.gov (United States)

    1981-04-01

    Delaware River Basing Ingham Justif icaticn--- L Creek, Pennsylvania. Phase I Inspection Do DEL-AWARE RIVER BASIN Availabilit T Co~es Avail and/or D...about 1.5H:IV and an unknown upstream slope below the water surface. The dam impounds a reservoir with a normal pool surface area of 12.4 acres and a...deep. It was once used to direct water to a mill downstream of the dam and is now in poor condition. The spillway Design Flood (SDF) chosen for this

  9. 7 CFR 1724.55 - Dam safety.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Dam safety. 1724.55 Section 1724.55 Agriculture... § 1724.55 Dam safety. (a) The provisions of this section apply only to RUS financed electric system... for Dam Safety,”(Guidelines), as applicable. A dam, as more fully defined in the Guidelines, is...

  10. Downstream passage of fish larvae and eggs through a small-sized reservoir, Mucuri river, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo S. Pompeu

    2011-12-01

    Full Text Available In South America, one important symptom of the failure of fish passages to sustain fish migratory recruitment is the inability of eggs and larvae to reach the nurseries. This is especially so when the breeding areas are located upstream of a reservoir, and the floodplain is downstream of the dam. Therefore, the transport of fish larvae and eggs across reservoir barriers is a key factor in the development of effective conservation strategies. In this paper, we evaluate the potential for migratory fish larvae and egg transportation across a small size reservoir in eastern Brazil. We sampled fish daily between 15th October 2002 and 15th February 2003 (spawning period in the Mucuri River, immediately upstream of the reservoir and downstream of the Santa Clara Power Plant dam. Our study was the first to indicate the possibility of successful larval passage through the reservoir of a hydroelectric reservoir and dam in South America, and showed that the passage of migratory fish larvae was associated significantly with residence time of water in the reservoir. The relatively short water residence time and elevated turbidity of the Santa Clara's reservoir waters during the rainy season certainly contributed to the successful passage, and can be considered as key factors for a priori evaluations of the feasibility of a downstream larval passage.

  11. Physical Model-Based Investigation of Reservoir Sedimentation Processes

    Directory of Open Access Journals (Sweden)

    Cheng-Chia Huang

    2018-03-01

    Full Text Available Sedimentation is a serious problem in the operations of reservoirs. In Taiwan, the situation became worse after the Chi-Chi Earthquake recorded on 21 September 1999. The sediment trap efficiency in several regional reservoirs has been sharply increased, adversely affecting the operations on water supplies. According to the field record, the average annual sediment deposition observed in several regional reservoirs in Taiwan has been increased. For instance, the typhoon event recorded in 2008 at the Wushe Reservoir, Taiwan, produced a 3 m sediment deposit upstream of the dam. The remaining storage capacity in the Wushe Reservoir was reduced to 35.9% or a volume of 53.79 million m3 for flood water detention in 2010. It is urgent that research should be conducted to understand the sediment movement in the Wushe Reservoir. In this study, a scale physical model was built to reproduce the flood flow through the reservoir, investigate the long-term depositional pattern, and evaluate sediment trap efficiency. This allows us to estimate the residual life of the reservoir by proposing a modification of Brune’s method. It can be presented to predict the lifespan of Taiwan reservoirs due to higher applicability in both the physical model and the observed data.

  12. Accumulation of floating microplastics behind the Three Gorges Dam

    International Nuclear Information System (INIS)

    Zhang, Kai; Gong, Wen; Lv, Jizhong; Xiong, Xiong; Wu, Chenxi

    2015-01-01

    We investigated the occurrence and distribution of microplastics in surface water from the Three Gorges Reservoir. Nine samples were collected via trawl sampling with a 112 μm mesh net. The abundances of microplastics were from 3407.7 × 10 3 to 13,617.5 × 10 3 items per square kilometer in the main stream of the Yangtze River and from 192.5 × 10 3 to 11,889.7 × 10 3 items per square kilometer in the estuarine areas of four tributaries. The abundance of microplastics in the main stream of the Yangtze River generally increased as moving closer to the Three Gorges Dam. The microplastics are made exclusively of polyethylene (PE), polypropylene (PP), and polystyrene (PS). Together with microplastics, high abundance of coal/fly ash was also observed in the surface water samples. Comparing with previously reported data, microplastics in the TGR were approximately one to three orders of magnitudes greater, suggesting reservoirs as potential hot spot for microplastic pollution. - Highlights: • Occurrence of microplastics was studied in surface water from the Three Gorges Reservoir. • Microplastics were identified as polyethylene, polypropylene, and polystyrene. • Abundance of microplastics was considerably higher than previously reported data. - Microplastics were observed in high abundance in surface water from the Three Gorges Reservoir implying reservoirs as structural controls where microplastics accumulate

  13. Perspectives on dam safety in Canada

    International Nuclear Information System (INIS)

    Halliday, R.

    2004-01-01

    Canadian dam safety issues were reviewed from the perspective of a water resources engineer who is not a dam safety practitioner. Several external factors affecting dam safety were identified along with perceived problems in dam safety administration. The author claims that the main weakness in safety practices can be attributed to provincial oversights and lack of federal engagement. Some additions to the Canadian Dam Safety Guidelines were proposed to address these weaknesses. Canada has hundreds of large dams and high hazard dams whose failure would result in severe downstream consequences. The safety of dams built on boundary waters shared with the United States have gained particular attention from the International Joint Commission. This paper also examined safety criteria for concerns such as aging dams, sabotage and global climate change that may compromise the safety of a dam. 26 refs

  14. An Investigation on Water Quality of Darlik Dam Drinking Water using Satellite Images

    Directory of Open Access Journals (Sweden)

    Erhan Alparslan

    2010-01-01

    Full Text Available Darlik Dam supplies 15% of the water demand of Istanbul Metropolitan City of Turkey. Water quality (WQ in the Darlik Dam was investigated from Landsat 5 TM satellite images of the years 2004, 2005, and 2006 in order to determine land use/land cover changes in the watershed of the dam that may deteriorate its WQ. The images were geometrically and atmospherically corrected for WQ analysis. Next, an investigation was made by multiple regression analysis between the unitless planetary reflectance values of the first four bands of the June 2005 Landsat TM image of the dam and WQ parameters, such as chlorophyll-a, total dissolved matter, turbidity, total phosphorous, and total nitrogen, measured at satellite image acquisition time at seven stations in the dam. Finally, WQ in the dam was studied from satellite images of the years 2004, 2005, and 2006 by pattern recognition techniques in order to determine possible water pollution in the dam. This study was compared to a previous study done by the authors in the Küçükçekmece water reservoir, also in Istanbul City.

  15. The Influence of Dams on Malaria Transmission in Sub-Saharan Africa.

    Science.gov (United States)

    Kibret, Solomon; Wilson, G Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

    2017-06-01

    The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.

  16. How Physical Processes are Informing River Management Actions at Marble Bluff Dam, Truckee River, Nevada

    Science.gov (United States)

    Bountry, J.; Godaire, J.; Bradley, D. N.

    2017-12-01

    At the terminus of the Truckee River into Pyramid Lake (Nevada, USA), upstream river management actions have dramatically reshaped the river landscape, posing significant challenges for the management of endangered aquatic species and maintenance of existing infrastructure. Within the last 100 years, upstream water withdrawal for human uses has resulted in a rapid lowering of Pyramid Lake which initiated up to 90 ft of channel incision. In 1976 Marble Bluff Dam was constructed to halt the upstream progression of channel incision and protect upstream agricultural lands, tribal resources, and infrastructure. Since construction an additional 40 ft of lake lowering and subsequent channel lowering now poses a potential risk to the structural integrity of the dam. The dynamic downstream river combined with ongoing reservoir sedimentation pose challenges to fish passage facilities that enable migration of numerous endangered cui-ui and threatened Lahontan Cutthroat Trout (LCT) to upstream spawning areas each year. These facilities include a fish lock at the dam, a fish bypass channel which allows fish to avoid the shallow delta area during low lake levels, and a meandering channel constructed by the Nature Conservancy to connect the bypass channel to the receding Pyramid Lake. The reservoir formed by Marble Bluff Dam has completely filled with sediment which impacts fish passage facilities. The original operating manual for the dam recommends year-round flushing of sediment through radial gates, but this can no longer be accomplished. During critical fish migration periods in the spring operators must ensure fish entrance channels downstream of the dam are not buried with released sediment and fish are not trapped in a portion of the reservoir full of sediment that would risk sending them back over the dam. To help inform future reservoir sediment and infrastructure management strategies, we bracket a range of potential river responses to lake level lowering and floods

  17. Dams and Levees: Safety Risks

    Science.gov (United States)

    Carter, N. T.

    2017-12-01

    The nation's flood risk is increasing. The condition of U.S. dams and levees contributes to that risk. Dams and levee owners are responsible for the safety, maintenance, and rehabilitation of their facilities. Dams-Of the more than 90,000 dams in the United States, about 4% are federally owned and operated; 96% are owned by state and local governments, public utilities, or private companies. States regulate dams that are not federally owned. The number of high-hazard dams (i.e., dams whose failure would likely result in the loss of human life) has increased in the past decade. Roughly 1,780 state-regulated, high-hazard facilities with structural ratings of poor or unsatisfactory need rehabilitation. Levees-There are approximately 100,000 miles of levees in the nation; most levees are owned and maintained by municipalities and agricultural districts. Few states have levee safety programs. The U.S. Army Corps of Engineers (Corps) inspects 15,000 miles of levees, including levees that it owns and local levees participating in a federal program to assist with certain post-flood repairs. Information is limited on how regularly other levees are inspected. The consequence of a breach or failure is another aspect of risk. State and local governments have significant authority over land use and development, which can shape the social and economic impacts of a breach or failure; they also lead on emergency planning and related outreach. To date, federal dam and levee safety efforts have consisted primarily of (1) support for state dam safety standards and programs, (2) investments at federally owned dams and levees, and (3) since 2007, creation of a national levee database and enhanced efforts and procedures for Corps levee inspections and assessments. In Public Law 113-121, enacted in 2014, Congress (1) directed the Corps to develop voluntary guidelines for levee safety and an associated hazard potential classification system for levees, and (2) authorized support for the

  18. Grouting Applications in Cindere Dam

    Directory of Open Access Journals (Sweden)

    Devrim ALKAYA

    2011-01-01

    Full Text Available Grouting is one of the most popular method to control the water leakage in fill dam constructions. With this regard this method is widely used in all the world. Geological and geotechnical properties of rock are important parameters affect the design of grouting. In this study, geotechnical properties of Cindere Dam's base rock and the grouting prosedure have been investigated with grouting pressure.

  19. Ririe Dam Release Test Assessment

    Science.gov (United States)

    2013-06-01

    Notes HEC - RAS Location Station (ft) Observation Notes 1420 Ririe Dam Ririe Dam 119,880 Gates opened and initial release started. 1455 115th St...16°F air temperature. Table A2. Observations made on 11 February 2013. Time Location Notes HEC - RAS Location Station (ft) Observation Notes...ERDC/CRREL TR-13-10 52 Time Location Notes HEC - RAS Location Station (ft) Observation Notes Travel Time* (sec) Vel.** (fps) 1224 5th

  20. Limno-reservoirs as a new landscape, environmental and touristic resource: Pareja Limno-reservoir as a case of study (Guadalajara, Spain)

    Science.gov (United States)

    Díaz-Carrión, I.; Sastre-Merlín, A.; Martínez-Pérez, S.; Molina-Navarro, E.; Bienes-Allas, R.

    2012-04-01

    A limno-reservoir is a hydrologic infrastructure with the main goal of generating a body of water with a constant level in the riverine zone of a reservoir, building a dam that makes de limno-reservoir independent from the main body of water. This dam can be built in the main river supplying the reservoir or any tributary as well flowing into it. Despite its novel conception and design, around a dozen are already operative in some Spanish reservoirs. This infrastructure allows the new water body to be independent of the main reservoir management, so the water level stability is its main distinctive characteristic. It leads to the development of environmental, sports and cultural initiatives; which may be included in a touristic exploitation in a wide sense. An opinion poll was designed in 2009 to be carried out the Pareja Limno-reservoir (Entrepeñas reservoir area, Tajo River Basin, central Spain). The results showed that for both, Pareja inhabitants and occasional visitors, the limno-reservoir has become an important touristic resource, mainly demanded during summer season. The performance of leisure activities (especially swimming) are being the main brand of this novel hydraulic and environmental infrastructure, playing a role as corrective and/or compensatory action which is needed to apply in order to mitigate the environmental impacts of the large hydraulic constructions.

  1. Investigation Of The Origin Of Various Water Sources In The Vicinity Of Ngancar Dam, Wonogiri Using Natural Isotopes

    International Nuclear Information System (INIS)

    Sidauruk, Paston; Indrojoyo; Wibagoyo; Pratikno, Bungkus; Evarista Ristin, P.I.

    2000-01-01

    The investigation of the origin of various water sources in the vicinity of Ngancar Dam, Wonogiri, using natural isotopes technique has been conducted. The study includes collecting and analyzing water samples from various sources in the vicinity of the dam such as reservoir water, water discharges, springs, local water well, rain water, water from piezometer and observation wells. For this investigation, natural isotopes composition and hydro chemical ions of the samples have been analyzed and interpreted. From the data interpretation, it is concluded that most of the water in various sources originated from water reservoir

  2. Developing Digital Image Techniques with Low-Cost Unmanned Mobile to Monitor the Safety of Dam and Affiliated Structure

    Science.gov (United States)

    Sung, Wen-Pei; Shih, Ming-Hsiang

    2016-04-01

    Global warming phenomena are increasingly serious, the El Niño and La Niña continue to occur repeatedly, causing the irregular drought and flood problem repeatedly. Mountain form of Taiwan is steep and storage ability of rainwater is insufficient to supply the livelihood of people and usage of industry which need to rely on rainwater reservoir. Thus, to ensure the water supply and self-reliance energy supply, one of ways to keep water resource is to build reservoir. Nevertheless, Taiwan is located on Pacific seismic belt; additionally, geological conditions are not fine, over-developed in the hills lead to more natural disasters in the future. Thus, strong shakes and typhoons which caused a degree of severe landslides around dam lead to reduce catchment of dam to result in affecting the safety of dam. Otherwise, the cracks and rusts in dam, induced by the defects of material, bad construction and seismic excitation respectively, thus, the mechanics phenomena of dam and its affiliated structures with crack are probing into the cause of stress concentration, induced high crack increase rate, affect the safety and usage of dam. This research is aimed at the safety evaluation technique of dam and its affiliated structures to develop three dimensional digital image correlation techniques for monitoring the safety of dam and its affiliated structures. Namely, developing the unmanned mobile on two axis of digital image correlation method is to detect the digital images from geometric scanning techniques for dam structure. This developed technique combined with Unmanned Aerial Vehicle (UAV) to develop the near filed scanning and monitoring techniques for local deformation and cracks on dam and its affiliated structures.

  3. Modeling of reservoir operation in UNH global hydrological model

    Science.gov (United States)

    Shiklomanov, Alexander; Prusevich, Alexander; Frolking, Steve; Glidden, Stanley; Lammers, Richard; Wisser, Dominik

    2015-04-01

    Climate is changing and river flow is an integrated characteristic reflecting numerous environmental processes and their changes aggregated over large areas. Anthropogenic impacts on the river flow, however, can significantly exceed the changes associated with climate variability. Besides of irrigation, reservoirs and dams are one of major anthropogenic factor affecting streamflow. They distort hydrological regime of many rivers by trapping of freshwater runoff, modifying timing of river discharge and increasing the evaporation rate. Thus, reservoirs is an integral part of the global hydrological system and their impacts on rivers have to be taken into account for better quantification and understanding of hydrological changes. We developed a new technique, which was incorporated into WBM-TrANS model (Water Balance Model-Transport from Anthropogenic and Natural Systems) to simulate river routing through large reservoirs and natural lakes based on information available from freely accessible databases such as GRanD (the Global Reservoir and Dam database) or NID (National Inventory of Dams for US). Different formulations were applied for unregulated spillway dams and lakes, and for 4 types of regulated reservoirs, which were subdivided based on main purpose including generic (multipurpose), hydropower generation, irrigation and water supply, and flood control. We also incorporated rules for reservoir fill up and draining at the times of construction and decommission based on available data. The model were tested for many reservoirs of different size and types located in various climatic conditions using several gridded meteorological data sets as model input and observed daily and monthly discharge data from GRDC (Global Runoff Data Center), USGS Water Data (US Geological Survey), and UNH archives. The best results with Nash-Sutcliffe model efficiency coefficient in the range of 0.5-0.9 were obtained for temperate zone of Northern Hemisphere where most of large

  4. System-Wide Significance of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs : Annual Report 1992.

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, James H.; Poe, Thomas P.

    1993-12-01

    Northern squawfish (Ptychocheilus oregonensis) predation on juvenile salmonids was characterized during 1992 at ten locations in the Columbia River below Bonneville Dam and at three locations in John Day Reservoir. During the spring and summer, 1,487 northern squawfish were collected in the lower Columbia River and 202 squawfish were sampled in John Day Reservoir. Gut content data, predator weight, and water temperature were used to compute a consumption index (CI) for northern squawfish, and overall diet was also described. In the Columbia River below Bonneville Dam, northern squawfish diet was primarily fish (spring 69%; summer 53%), most of which were salmonids. Salmonids were also the primary diet component in the Bonneville Dam tailrace, John Day Dam forebay, and the McNary Dam tailrace. Crustaceans were the dominant diet item at the John Day mid-reservoir location, although sample sizes were small. About half of the non-salmonid preyfish were sculpins. The consumption index (CI) of northern squawfish was generally higher during summer than during spring. The highest CI`s were observed during summer in the tailrace boat restricted zones of Bonneville Dam (CI = 7.8) and McNary Dam (CI = 4.6). At locations below Bonneville Dam, CI`s were relatively low near Covert`s Landing and Rooster Rock, higher at four locations between Blue Lake and St. Helens, and low again at three downriver sites (Kalama, Ranier, and Jones Beach). Northern squawfish catches and CI`s were noticeably higher throughout the lower Columbia compared to mid-reservoir sites further upriver sampled during 1990--92. Predation may be especially intense in the free-flowing section of the Columbia River below Bonneville Dam. Smallmouth bass (Micropterus dolomieui; N = 198) ate mostly fish -- 25% salmonids, 29% sculpins, and 46% other fish. Highest catches of smallmouth bass were in the John Day Dam forebay.

  5. Reliability and Robustness Analysis of the Masinga Dam under Uncertainty

    Directory of Open Access Journals (Sweden)

    Hayden Postle-Floyd

    2017-02-01

    Full Text Available Kenya’s water abstraction must meet the projected growth in municipal and irrigation demand by the end of 2030 in order to achieve the country’s industrial and economic development plan. The Masinga dam, on the Tana River, is the key to meeting this goal to satisfy the growing demands whilst also continuing to provide hydroelectric power generation. This study quantitatively assesses the reliability and robustness of the Masinga dam system under uncertain future supply and demand using probabilistic climate and population projections, and examines how long-term planning may improve the longevity of the dam. River flow and demand projections are used alongside each other as inputs to the dam system simulation model linked to an optimisation engine to maximise water availability. Water availability after demand satisfaction is assessed for future years, and the projected reliability of the system is calculated for selected years. The analysis shows that maximising power generation on a short-term year-by-year basis achieves 80%, 50% and 1% reliability by 2020, 2025 and 2030 onwards, respectively. Longer term optimal planning, however, has increased system reliability to up to 95% in 2020, 80% in 2025, and more than 40% in 2030 onwards. In addition, increasing the capacity of the reservoir by around 25% can significantly improve the robustness of the system for all future time periods. This study provides a platform for analysing the implication of different planning and management of Masinga dam and suggests that careful consideration should be given to account for growing municipal needs and irrigation schemes in both the immediate and the associated Tana River basin.

  6. The effect of material properties on the seismic performance of Arch Dams

    Directory of Open Access Journals (Sweden)

    B. Sevim

    2011-08-01

    Full Text Available The paper investigates the effect of material properties on the seismic performance of arch dam-reservoir-foundation interaction systems based on the Lagrangian approach using demand-capacity ratios. Type-5 arch dam is selected as a numerical application. The linear time history analyses of the arch dam-reservoir-foundation interaction system are carried out for different material properties. The foundation is taken into account as massless; behaviour of the reservoir is assumed to be linearly elastic, inviscid and irrotational. The north-south component of the Erzincan earthquake in 1992 is chosen as a ground motion. Dynamic equations of motions obtained from 3-D finite element modelling of the coupled system are solved by using the Newmark integration algorithm. The damage levels of the coupled system for the different material properties are demonstrated by using demand-capacity ratios and cumulative inelastic durations. The time histories and maximum values of the displacements and principal stresses, and performance curves, are obtained from linear analyses. It is clearly seen from the study that the different material properties affect the seismic behaviour of the dam.

  7. Three-dimensional earthquake analysis of roller-compacted concrete dams

    Directory of Open Access Journals (Sweden)

    M. E. Kartal

    2012-07-01

    Full Text Available Ground motion effect on a roller-compacted concrete (RCC dams in the earthquake zone should be taken into account for the most critical conditions. This study presents three-dimensional earthquake response of a RCC dam considering geometrical non-linearity. Besides, material and connection non-linearity are also taken into consideration in the time-history analyses. Bilinear and multilinear kinematic hardening material models are utilized in the materially non-linear analyses for concrete and foundation rock respectively. The contraction joints inside the dam blocks and dam–foundation–reservoir interaction are modeled by the contact elements. The hydrostatic and hydrodynamic pressures of the reservoir water are modeled with the fluid finite elements based on the Lagrangian approach. The gravity and hydrostatic pressure effects are employed as initial condition before the strong ground motion. In the earthquake analyses, viscous dampers are defined in the finite element model to represent infinite boundary conditions. According to numerical solutions, horizontal displacements increase under hydrodynamic pressure. Besides, those also increase in the materially non-linear analyses of the dam. In addition, while the principle stress components by the hydrodynamic pressure effect the reservoir water, those decrease in the materially non-linear time-history analyses.

  8. Effects on the upstream flood inundation caused from the operation of Chao Phraya Dam

    Directory of Open Access Journals (Sweden)

    Sutham Visutimeteegorn

    2007-11-01

    Full Text Available During the flooding events, the operation of Chao Phraya Dam to control downstream water discharge is one of the causes of the inundation occuring over the upstream area. The purposes of this research are to study the effects of the operation of Chao Phraya Dam upon the upstream flood inundation and to find out the new measures of the flood mitigation in the upstream areas of Chao Phraya Dam by using a hydrodynamic model. The results show that Manning's n in the Chao Phraya River and its tributaries is 0.030-0.035 in the main channels and 0.050-0.070 in the flood plain areas. The backwater due to the operation of the Chao Praya dam affects as far as 110 kilometers upstream. New methods of water diversion can mitigate the flood inundation without the effect on the floating rice fields. The construction of reservoirs in the Upper Sakaekang River Basin and the Upper Yom River Basin will mitigate the flood not only in their own basins but also in the Lower Chao Phraya River Basin. The coordinated operation of the Chao Phraya Dam, the regulators and the upper basin reservoirs will efficiently mitigate the flood inundation.

  9. The blue water footprint of the world's artificial reservoirs for hydroelectricity, irrigation, residential and industrial water supply, flood protection, fishing and recreation

    OpenAIRE

    Hogeboom, Hendrik Jan; Knook, Luuk; Hoekstra, Arjen Y.

    2018-01-01

    For centuries, humans have resorted to building dams to gain control over freshwater available for human consumption. Although dams and their reservoirs have made many important contributions to human development, they receive negative attention as well, because of the large amounts of water they can consume through evaporation. We estimate the blue water footprint of the world's artificial reservoirs and attribute it to the purposes hydroelectricity generation, irrigation water supply, resid...

  10. Sediment impact assessment of check-dam removal strategies on a mountain river in Taiwan

    Science.gov (United States)

    Kuo, W.; Wang, H.; Stark, C. P.

    2011-12-01

    Dam removal is important for reconnecting river habitats and restoring the free flow of water and sediment, so managing accumulated sediments is crucial in dam removal planning as the cost and potential impacts of dam removal can vary substantially depending on local conditions. A key uncertainty in dam removal is the fate of reservoir sediment stored upstream of the dam. Release of impounded sediment could raise downstream bed elevations leading to flooding, increase lateral channel mobility leading to bank erosion, and potentially bury downstream ecologically sensitive habitats if the sediment is fine. The ability to predict the sediment impacts of dam removal in highly sediment-filled systems is thus increasingly important as the number of such dam-removal cases is growing. Due to the safety concerns and the need for habitat restoration for the Formosan landlocked salmon, the Shei-Pa National Park in Taiwan removed the 15m high Chijiawan "No. 1 Check Dam" in late May 2011. During the planning process prior to removal, we conducted field surveys, numerical simulations, and flume experiments to determine sediment impacts and to suggest appropriate dam removal strategies. We collected river-bed topography and sediment bulk samples in 2010 to establish the channel geometry and grain-size distribution for modeling input. The scaled flume experiment was designed to provide insights on how and if the position of a notch location and size would affect the rate and amount of reservoir erosion under particular discharges. Observations indicated that choices of notch location can force the river to migrate differently. For long-term prediction, we used the quasi-two-dimensional numerical model NETSTARS (Network of Stream Tube model for Alluvial River Simulation) to simulate the channel responses. These simulations indicated that high suspended sediment concentrations would be the most likely major concern in the first year, while concerns for downstream sediment deposition

  11. Blockage of migration routes by dam construction: can migratory fish find alternative routes?

    Directory of Open Access Journals (Sweden)

    Rosimeire Ribeiro Antonio

    Full Text Available The present study explored the interaction between the upriver migration of fish and the blockage of their migration routes by dam construction. Specifically, we studied (i the capacity of migratory fish to locate alternative routes in the presence of an obstacle, and (ii the behavior of the fish after they were artificially transferred to the reservoir. With the use of the mark-recapture technique (tagging, the study was carried out near Porto Primavera Dam (UHE Engenheiro Sérgio Motta between 1994 and 1999, a period prior to the closure of the floodgates and the installation and operation of the fish pass facilities. The fish were caught in the dam forebay downstream, marked with LEA type tags, and released upstream (5113 individuals; 14 species and downstream (1491; 12 from the dam. The recaptures were carried out by local professional and amateur fishermen. A total of 188 individuals (2.8% were recaptured, mostly the curimba Prochilodus lineatus. Nearly half of the recaptures downstream occurred in tributaries, especially in the Paranapanema River, indicating that in the presence of an obstacle the fish are able to locate alternative migration routes. The remainder stayed in the main channel of the Paraná River, at a mean distance of less than 50 km from the release point. Of the fish released upriver from the dam, approximately half were recaptured downriver. Although the river was only partly dammed, the movement of the fish downriver suggests that they became disoriented after being transferred. Those that remained upriver avoided the reservoir and moved, rather rapidly, toward the lotic stretches farther upstream. From these results it is clear that, in the course of the decision process in installing fish passes, it is necessary to take into account the existence of spawning and nursery areas downriver and upriver from the reservoir.

  12. The blue water footprint of the world's artificial reservoirs for hydroelectricity, irrigation, residential and industrial water supply, flood protection, fishing and recreation

    NARCIS (Netherlands)

    Hogeboom, Hendrik Jan; Knook, Luuk; Hoekstra, Arjen Y.

    2018-01-01

    For centuries, humans have resorted to building dams to gain control over freshwater available for human consumption. Although dams and their reservoirs have made many important contributions to human development, they receive negative attention as well, because of the large amounts of water they

  13. Analysis of selected reservoirs functioning in the Wielkopolska region

    Directory of Open Access Journals (Sweden)

    Mariusz Sojka

    2017-12-01

    Full Text Available The paper presents the problems related to the functioning of reservoirs in the Wielkopolska province and suggests their possible solutions. The reservoirs chosen as examples include typical dam constructions with a single water body (Jeziorsko, Rydzyna, two water body objects with separated preliminary part (Stare Miasto, Kowalskie, Radzyny and lateral constructions (Pakosław, Jutrosin. The reservoirs were built in period from 1970 to 2014. They differ in construction, functions and water management rules. Analysis of the main problems related to the reservoir functioning is aimed at finding ways of improving the construction of new reservoirs that would satisfy increasingly stringent environmental and legal restrictions and the methods of water management in the reservoirs. On the basis of a questionnaire filled in by the reservoir operators, the main problem is water quality. Especially the huge inflow of biogenic compounds causes blooms of algae and overgrowth with riparian vegetation. Some difficulties are also related to management of the reservoirs of multi-purpose operation. It is difficult to take into account the requirements of environmental flow maintenance, flood protection, water supply for agriculture and water use for tourism and recreation and hydropower generation, etc.

  14. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1. Introduction. Sediment ... rendered water storage structures useless in less than 25 years. ... reservoir, thus reducing the space available for water storage and ...

  15. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  16. Effects of water-supply reservoirs on streamflow in Massachusetts

    Science.gov (United States)

    Levin, Sara B.

    2016-10-06

    State and local water-resource managers need modeling tools to help them manage and protect water-supply resources for both human consumption and ecological needs. The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, has developed a decision-support tool to estimate the effects of reservoirs on natural streamflow. The Massachusetts Reservoir Simulation Tool is a model that simulates the daily water balance of a reservoir. The reservoir simulation tool provides estimates of daily outflows from reservoirs and compares the frequency, duration, and magnitude of the volume of outflows from reservoirs with estimates of the unaltered streamflow that would occur if no dam were present. This tool will help environmental managers understand the complex interactions and tradeoffs between water withdrawals, reservoir operational practices, and reservoir outflows needed for aquatic habitats.A sensitivity analysis of the daily water balance equation was performed to identify physical and operational features of reservoirs that could have the greatest effect on reservoir outflows. For the purpose of this report, uncontrolled releases of water (spills or spillage) over the reservoir spillway were considered to be a proxy for reservoir outflows directly below the dam. The ratio of average withdrawals to the average inflows had the largest effect on spillage patterns, with the highest withdrawals leading to the lowest spillage. The size of the surface area relative to the drainage area of the reservoir also had an effect on spillage; reservoirs with large surface areas have high evaporation rates during the summer, which can contribute to frequent and long periods without spillage, even in the absence of water withdrawals. Other reservoir characteristics, such as variability of inflows, groundwater interactions, and seasonal demand patterns, had low to moderate effects on the frequency, duration, and magnitude of spillage. The

  17. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  18. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    Science.gov (United States)

    Velpuri, N. M.; Senay, G. B.

    2012-10-01

    Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in situ datasets. In this study, we used 12 yr (1998-2009) of existing multi-source satellite and model-assimilated global weather data. We used a calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of the Gibe III dam using three different approaches - a historical approach, a rainfall based approach, and a statistical approach to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the Gibe III dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8-10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 1-2 m (95% confidence) compared to the lake level modeled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modeling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam commencement. Areas

  19. Climate change effects on design floods for dams in Sweden

    International Nuclear Information System (INIS)

    Andreasson, J.; Bergstroem, S.

    2008-01-01

    Since 1990 new guidelines for hydrological design of the Swedish hydropower system are being implemented. The technique is based on a critical combination of extreme precipitation, extreme snowmelt and an operation strategy for multi-reservoir systems. Hydrological modeling is a central component, as is a prescribed design precipitation sequence. At the time when the guidelines were developed it was not possible to account for possible consequences of a changing climate. Sensitivity analyses using four different regional climate change scenarios (2071-2100) has been carried out for four important Swedish dams and also for the largest lake in Sweden, Lake Vanern. The research project was financed by Elforsk and the Swedish Dam Safety Authority (Svenska Kraftnat) and it was reported in 2006/2007. Some summarizing conclusions are: Changes in the mean climate results in smaller design snow pack according to all scenarios. This component acts towards decreased design inflows and water levels at most locations. Extreme precipitation can be expected to increase at most places in Sweden according to the climate scenarios. This component acts towards increased design inflows and water levels at most locations. Depending on how changes in the mean climate and in the extremes interact, the change in design inflows and water levels can be either an increase or a decrease. The effect depends both on the location of the dam and on the choice of climate scenario. This calls for site-specific analysis for each dam. In 2007 the second edition of the guidelines for hydrological design was issued in which also the question of climate change have been addressed. The first sensitivity analyses are now being extended within a new 2-year research project also funded jointly by Elforsk and the Swedish Dam Safety Authority (Svenska Kraftnat). The aim is to increase the number of regional climate scenarios and the number of high hazard dams in the analysis, but also to move the scenarios

  20. Carbon emission as a function of energy generation in hydroelectric reservoirs in Brazilian dry tropical biome

    International Nuclear Information System (INIS)

    Ometto, Jean P.; Cimbleris, André C.P.; Santos, Marco A. dos; Rosa, Luiz P.; Abe, Donato; Tundisi, José G.; Stech, José L.; Barros, Nathan; Roland, Fábio

    2013-01-01

    Most energy generation globally is fueled by coal and oil, raising concerns about greenhouse gas emissions. Hydroelectric reservoirs are anthropogenic aquatic systems that occur across a wide geographical extent, and, in addition to their importance for energy production, they have the potential to release two important greenhouse gases (GHGs), carbon dioxide and methane. We report results from an extensive study of eight hydroelectric reservoirs located in central and southeastern tropical Brazil. In the Brazilian dry tropical biome reservoirs, emissions (in tons of CO 2 Eq. per MW h) varied from 0.01 to 0.55, and decreased with reservoir age. Total emissions were higher in the reservoir lake when compared to the river downstream the dam; however, emissions per unit area, in the first kilometer of the river after the dam, were higher than that in the reservoir. The results showed, despite higher carbon emissions per energy production in the youngest reservoirs, lower emission from hydroelectric reservoirs from the studied region in relation to thermo electrical supply, fueled by coal or fossil fuel. The ratio emission of GHG per MWh produced is an important parameter in evaluating the service provided by hydroelectric reservoir and for energy planning policies. - Highlights: ► Hydroelectric reservoirs construction is growing worldwide. ► The effect of hydropower reservoir in the carbon cycle is dependent on environment characteristics. ► Carbon emissions per energy production are higher in the youngest tropical savannah reservoirs. ► Methane emissions decrease with reservoir age in tropical savannah reservoirs. ► In general, the effect of hydropower in the carbon cycle is lower than other energy sources

  1. Accounting for Greenhouse Gas Emissions from Reservoirs ...

    Science.gov (United States)

    Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used as a ‘basis for future methodological development’ due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. In the U.S., research approaches include: 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane em

  2. Accouting for Greenhouse Gas Emissions from Reservoirs

    Science.gov (United States)

    Beaulieu, J. J.; Deemer, B. R.; Harrison, J. A.; Nietch, C. T.; Waldo, S.

    2016-12-01

    Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used as a `basis for future methodological development' due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. In the U.S., research approaches include: 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane emissions linked to the National Lakes Assessment.

  3. MODELLING THE EFFECTS OF LAND-USE CHANGES ON CLIMATE: A CASE STUDY ON YAMULA DAM

    OpenAIRE

    Ü. Köylü; A. Geymen

    2016-01-01

    Dams block flow of rivers and cause artificial water reservoirs which affect the climate and the land use characteristics of the river basin. In this research, the effect of the huge water body obtained by Yamula Dam in Kızılırmak Basin is analysed over surrounding spatial’s land use and climate change. Mann Kendal non-parametrical statistical test, Theil&Sen Slope method, Inverse Distance Weighting (IDW), Soil Conservation Service-Curve Number (SCS-CN) methods are integrated for spa...

  4. PRINCIPAL STRESSES IN NON-LINEAR ANALYSIS OF BAKUN CONCRETE FACED ROCKFILL DAM

    Directory of Open Access Journals (Sweden)

    Mohd Hilton Ahmad

    2017-11-01

    Full Text Available With rapid population growth and accelerating economic development, much of the world’s WATER which requires urgent attention to ensure sustainable use. Nowadays, Concrete Faced Rockfill Dam (CFRD is preferred among dam consultant due to its advantages. They are designed to withstand all applied loads; namely gravity load due to its massive weight and hydrostatic load due to water thrust from the reservoir. Bakun CFRD, which ranks as the second highest CFRD in the world when completed, is analyzed to its safety due to both loads mentioned earlier by using Finite Element Method. 2-D plane strain finite element analysis of non-linear Duncan-Chang hyperbolic Model which formulated by Duncan and Chang is used to study the structural response of the dam in respect to the deformation and stresses of Main dam of Bakun’s CFRD project. Dead-Birth-Ghost element technique was used to simulate sequences of construction of the dam as well as during reservoir fillings. The comparison of rigid and flexible foundation on the behaviour of the dam was discussed. The maximum and minimum principal stresses are the maximum and minimum possible values of the normal stresses. The maximum principal stress controls brittle fracture. In the finite element modeling the concrete slab on the upstream was represented through six-noded element, while the interface characteristic between dam body and concrete slab was modeled using interface element. The maximum settlement and stresses of the cross section was founded and the distribution of them were discussed and tabulated in form of contours.

  5. Hazardous Waste Cleanup: Chemical Waste Management of NJ in Newark, New Jersey

    Science.gov (United States)

    Chemical Waste Management of NJ is located at 100 Lister Avenue in Newark, New Jersey. This section of Newark has been industrial since the late 1800s when the marshlands of the Passaic River were filled in with a mixture of coal ash, construction debris

  6. 76 FR 9224 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ

    Science.gov (United States)

    2011-02-17

    ... Operation Regulations; Hackensack River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... Hackensack River, mile 3.4, at Jersey City, New Jersey. The deviation is necessary to repair structural steel... Bridge, across the Hackensack River at mile 3.4, has a vertical clearance in the closed position of 40...

  7. 76 FR 27250 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ

    Science.gov (United States)

    2011-05-11

    ... Operation Regulations; Hackensack River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... Hackensack River, mile 3.4, at Jersey City, New Jersey. The deviation is necessary to repair structural steel... Bridge, across the Hackensack River at mile 3.4, has a vertical clearance in the closed position of 40...

  8. 76 FR 47440 - Drawbridge Operation Regulations; Passaic River, Jersey City, NJ

    Science.gov (United States)

    2011-08-05

    ... Operation Regulations; Passaic River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... deviation from the regulation governing the operation of the Route 1 & 9 Bridge across the Passaic River, mile 1.8, at Jersey City, New Jersey. The deviation is necessary to facilitate bridge painting...

  9. 75 FR 78601 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ, Maintenance

    Science.gov (United States)

    2010-12-16

    ... Operation Regulations; Hackensack River, Jersey City, NJ, Maintenance AGENCY: Coast Guard, DHS. ACTION... 3.1, across the Hackensack River, at Jersey City, New Jersey. Under this temporary deviation a two.... SUPPLEMENTARY INFORMATION: The Witt Penn Bridge, across the Hackensack River at mile 3.1 has a vertical...

  10. 75 FR 16009 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ, Maintenance

    Science.gov (United States)

    2010-03-31

    ... Regulations; Hackensack River, Jersey City, NJ, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of..., mile 1.8, across the Hackensack River at Jersey City, New Jersey. This deviation allows the bridge... across the Hackensack River at mile 1.8, at Jersey City, New Jersey, has a vertical clearance in the...

  11. 75 FR 63398 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ

    Science.gov (United States)

    2010-10-15

    ... Operation Regulations; Hackensack River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... across the Hackensack River, mile 1.8, at Jersey City, New Jersey. The deviation allows the bridge owner... INFORMATION: The Route 1 & 9 Lincoln Highway Bridge, across the Hackensack River, mile 1.8, at Jersey City...

  12. 76 FR 4818 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ

    Science.gov (United States)

    2011-01-27

    ... Operation Regulations; Hackensack River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... Hackensack River, mile 6.9, at Secaucus, New Jersey. The deviation is necessary for electrical rehabilitation...-9826. SUPPLEMENTARY INFORMATION: The Upper Hack Bridge, across the Hackensack River at mile 6.9 has a...

  13. 75 FR 68704 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ

    Science.gov (United States)

    2010-11-09

    ... Operation Regulations; Hackensack River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... the Hackensack River, at Secaucus, New Jersey. Under this temporary deviation the bridge may remain in.... SUPPLEMENTARY INFORMATION: The Upper Hack Bridge, across the Hackensack River at mile 6.9 has a vertical...

  14. 76 FR 4819 - Drawbridge Operation Regulations; Passaic River, Jersey City, NJ

    Science.gov (United States)

    2011-01-27

    ... Operation Regulations; Passaic River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... deviation from the regulation governing the operation of the Route 1 & 9 Bridge across the Passaic River, mile 1.8, at Jersey City, New Jersey. The deviation is necessary for bridge painting. This deviation...

  15. 76 FR 11959 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ, Maintenance

    Science.gov (United States)

    2011-03-04

    ... Operation Regulations; Hackensack River, Jersey City, NJ, Maintenance AGENCY: Coast Guard, DHS. ACTION... 3.1, across the Hackensack River, at Jersey City, New Jersey. The deviation is necessary to perform... River at mile 3.1 has a vertical clearance in the closed position of 35 feet at mean high water and 40...

  16. 78 FR 66266 - Drawbridge Operation Regulations; Hackensack River, Jersey City, NJ

    Science.gov (United States)

    2013-11-05

    ... Regulations; Hackensack River, Jersey City, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation... from the regulations governing the operation of the Path (Railroad) Bridge across the Hackensack River, mile 3.0, at Jersey City, New Jersey. Under this temporary deviation, the bridge may remain in the...

  17. 78 FR 36658 - Safety Zone; Delaware River Waterfront Corp. Fireworks Display, Delaware River; Camden, NJ

    Science.gov (United States)

    2013-06-19

    ... portion of the Delaware River from operating while a fireworks event is taking place. This temporary...-AA00 Safety Zone; Delaware River Waterfront Corp. Fireworks Display, Delaware River; Camden, NJ AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary...

  18. 75 FR 66795 - Enesco, LLC, Gund Division, Distribution Center, Edison, NJ; Notice of Affirmative Determination...

    Science.gov (United States)

    2010-10-29

    ... Division, Distribution Center, Edison, NJ; Notice of Affirmative Determination Regarding Application for..., Distribution Center, Edison, New Jersey (subject firm). The determination was issued on August 27, 2010. The...). The workers are engaged in activities related to the supply of packaging and distribution services...

  19. 76 FR 11399 - Proposed Amendment to and Establishment of Restricted Areas, Warren Grove; NJ

    Science.gov (United States)

    2011-03-02

    ... that the FAA take this action due to the increased need for aircrew training in high-altitude weapons... increased aircrew training in high altitude weapons delivery tactics. This training requires higher... Grove Range, NJ, in order to raise the maximum altitude of the range from the current 14,000 feet mean...

  20. Scenedesmus sp. NJ-1 isolated from Antarctica: a suitable renewable lipid source for biodiesel production.

    Science.gov (United States)

    Chen, Zhuo; Gong, Yangmin; Fang, Xiantao; Hu, Hanhua

    2012-11-01

    Microalgal lipids are promising alternative feedstocks for biodiesel production. Scenedesmus sp. NJ-1, an oil-rich freshwater microalga isolated from Antarctica, was identified to be a suitable candidate to produce biodiesel in this study. This strain could grow at temperatures ranging from 4 to 35 °C. With regular decrease in nitrate concentration in the medium, large quantities of triacylglycerols accumulated under batch culture conditions detected by thin layer chromatography and BODIPY 505/515 fluorescent staining. Scenedesmus sp. NJ-1 achieved the average biomass productivity of 0.105 g l⁻¹ d⁻¹ (dry weight) and nearly the highest lipid content (35 % of dry cell weight) was reached at day 28 in the batch culture. Neutral lipids accounted for 78 % of total lipids, and C18:1 (n-9), C16:0 were the major fatty acids in total lipids, composing 37 and 20 % of total fatty acids of Scenedesmus sp. NJ-1 grown for 36 days, respectively. These results suggested that Scenedesmus sp. NJ-1 was a good source of microalgal oils for biodiesel production.

  1. The Oil Game: Generating Enthusiasm for Geosciences in Urban Youth in Newark, NJ

    Science.gov (United States)

    Gates, Alexander E.; Kalczynski, Michael J.

    2016-01-01

    A hands-on game based upon principles of oil accumulation and drilling was highly effective at generating enthusiasm toward the geosciences in urban youth from underrepresented minority groups in Newark, NJ. Participating 9th-grade high school students showed little interest in the geosciences prior to participating in the oil game, even if they…

  2. constNJ: an algorithm to reconstruct sets of phylogenetic trees satisfying pairwise topological constraints.

    Science.gov (United States)

    Matsen, Frederick A

    2010-06-01

    This article introduces constNJ (constrained neighbor-joining), an algorithm for phylogenetic reconstruction of sets of trees with constrained pairwise rooted subtree-prune-regraft (rSPR) distance. We are motivated by the problem of constructing sets of trees that must fit into a recombination, hybridization, or similar network. Rather than first finding a set of trees that are optimal according to a phylogenetic criterion (e.g., likelihood or parsimony) and then attempting to fit them into a network, constNJ estimates the trees while enforcing specified rSPR distance constraints. The primary input for constNJ is a collection of distance matrices derived from sequence blocks which are assumed to have evolved in a tree-like manner, such as blocks of an alignment which do not contain any recombination breakpoints. The other input is a set of rSPR constraint inequalities for any set of pairs of trees. constNJ is consistent and a strict generalization of the neighbor-joining algorithm; it uses the new notion of maximum agreement partitions (MAPs) to assure that the resulting trees satisfy the given rSPR distance constraints.

  3. 78 FR 21849 - Television Broadcasting Services; Ely, NV to Middletown Township, NJ

    Science.gov (United States)

    2013-04-12

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [MB Docket No. 13-72; RM-11694, DA 13-448] Television Broadcasting Services; Ely, NV to Middletown Township, NJ AGENCY: Federal Communications... CFR Part 73 Television. Federal Communications Commission. Barbara A. Kreisman, Chief, Video Division...

  4. Policy Considerations for Greenhouse Gas Emissions from Freshwater Reservoirs

    Directory of Open Access Journals (Sweden)

    Kirsi Mäkinen

    2010-06-01

    Full Text Available Emerging concern over greenhouse gas (GHG emissions from wetlands has prompted calls to address the climate impact of dams in climate policy frameworks. Existing studies indicate that reservoirs can be significant sources of emissions, particularly in tropical areas. However, knowledge on the role of dams in overall national emission levels and abatement targets is limited, which is often cited as a key reason for political inaction and delays in formulating appropriate policies. Against this backdrop, this paper discusses the current role of reservoir emissions in existing climate policy frameworks. The distance between a global impact on climate and a need for local mitigation measures creates a challenge for designing appropriate mechanisms to combat reservoir emissions. This paper presents a range of possible policy interventions at different scales that could help address the climate impact of reservoirs. Reservoir emissions need to be treated like other anthropogenic greenhouse gases. A rational treatment of the issue requires applying commonly accepted climate change policy principles as well as promoting participatory water management plans through integrated water resource management frameworks. An independent global body such as the UN system may be called upon to assess scientific information and develop GHG emissions policy at appropriate levels.

  5. National Program for Inspection of Non-Federal Dams. New Pond Dam (MA 00779), Massachusetts Coastal Basin, Easton, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1981-07-01

    formerly provided irrigation water for the Hammond-Fuller i cranberry bogs. At the present the reservoir continues to service some bogs approximately 2...there are few depressions or irregularities. Vegetation along the edges of the crest consist of short brush, scattered trees up to 22 in. diameter...dam formerly provided irrigation water for cranberry bogs downstream and continues to service some bogs although the owners of the bogs have no

  6. Analysis of the behaviour of embankment dams during and after impoundment; Analyse du comportement de barrages en remblai pendant et apres leur mise en eau

    Energy Technology Data Exchange (ETDEWEB)

    Massiera, M. [Moncton Univ., Moncton, NB (Canada). Dept. of Civil Engineering; Szostak-Chrzanowski, A; Bazanowski, M. [New Brunswick Univ., Fredericton, NB (Canada). Canadian Centre for Geodetic Engineering; Withaker, C. [Metropolitan Water District of Southern California MWD, Glendora, CA (United States)

    2009-07-01

    This paper analyzed the behaviour of 2 embankment dams during impoundment. The study compared the values of the observed and calculated displacements of the crest during the initial filling of the reservoirs at the zoned earth West Dam in California and the Tounustouc concrete face rockfill dam (CFRD) in Quebec. The calculations were performed using finite element analysis. Rock and earthfill dams constructed on moraine deposits are known to deform under the influence of water load as the reservoir is filled. Therefore, this study also analyzed the long term deformations of the West Dam during 4 subsequent years of operation of the reservoir. Modelling rock and earthfill dams takes into account the nonlinear behaviour of the construction materials; interaction between the structure and the underlying soil and rock strata; influence of water load on the structure and on the foundation bedrock; and the effects of water saturation. This paper showed that geotechnical and geodetic monitoring may provide a warning system in case of abnormal behaviour of the embankment dam. In tectonically active zones, monitoring surveys may also provide information on the effects of seismic disturbances. 18 refs., 11 figs.

  7. Geophysical Investigations at Hidden Dam, Raymond, California: Summary of Fieldwork and Data Analysis

    Science.gov (United States)

    Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

    2010-01-01

    Geophysical field investigations have been carried out at the Hidden Dam in Raymond, California for the purpose of better understanding the hydrogeology and seepage-related conditions at the site. Known seepage areas on the northwest right abutment area of the downstream side of the dam are documented by Cedergren. Subsequent to the 1980 seepage study, a drainage blanket with a subdrain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain within the downstream portion of the dam. The purpose of the current geophysical work is to (1) identify present-day seepage areas that may not be evident due to the effectiveness of the drainage blanket in redirecting seepage water, and (2) provide information about subsurface geologic structures that may control subsurface flow and seepage. These tasks are accomplished through the use of two complementary electrical geophysical methods, self-potentials (SP) and direct-current (DC) electrical resistivity, which have been commonly utilized in dam-seepage studies. SP is a passive method that is primarily sensitive to active subsurface groundwater flow and seepage, whereas DC resistivity is an active-source method that is sensitive to changes in subsurface lithology and groundwater saturation. The focus of this field campaign was on the downstream area on the right abutment, or northwest side of the dam, as this is the main area of interest regarding seepage. Two exploratory self-potential lines were also collected on the downstream left abutment of the dam to identify

  8. COMPREHENSIVE ANALYSIS ON SEEPAGE AND STRUCTURAL STABILITY OF EARTH-ROCK DAM: A CASE STUDY OF XIQUANYAN DAM IN CHINA

    Directory of Open Access Journals (Sweden)

    Qingqing GUO

    2016-07-01

    . The earth-rock dam of Xiquanyan Reservoir near Harbin city in China is also selected as case study to illustrate the described method.

  9. A Study of the Impact of Dams on Streamflow and Sediment Retention in the Mekong River Basin

    Science.gov (United States)

    Munroe, T.; Anderson, E.; Markert, K. N.; Griffin, R.

    2017-12-01

    Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. Current studies that assess the hydrological impact of dams in the region focus on only one or a small subset (SWAT), a rainfall-runoff hydrologic model to determine change in streamflow and sedimentation in the Mekong Basin before and after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

  10. Modelling the impact of dam removal on geomorphic channel response and sediment delivery: an Austrian case study

    Science.gov (United States)

    Pöppl, Ronald; Coulthard, Tom; Keesstra, Saskia; Keiler, Margreth

    2015-04-01

    Dams are often considered to have the most significant impact on rivers as dam construction generally reduces downstream sediment fluxes which further involves geomorphic changes in the affected river reaches. Since many dams no longer fulfill their intended purpose (e.g. due to siltation), are dangerous (e.g. catastrophic dam failures) and/or are ecologically damaging (e.g. habitat destruction), within the last two decades several dams have been removed and many more are already proposed for removal. Unfortunately, there is still only little empirical knowledge about the geomorphic consequences of dam removals and the related sediment release which represents a big challenge for river management. Modelling is one way to approach this problem. In the presented study we modelled the impacts of dam removal on geomorphic channel processes, channel morphology and sediment delivery further considering the role of channel engineering measures and reservoir excavation within a river reach impacted by a series of dams using the landscape evolution model CAESAR-Lisflood. The model was run with data from a small catchment located in Lower Austria. Modelled geomorphic channel changes and sediment fluxes were spatio-temporally analyzed, related to real-world data and are discussed in the context of river management issues.

  11. Measurement of Lake Roosevelt biota in relation to reservoir operations. 1991 Annual report

    International Nuclear Information System (INIS)

    Griffith, J.R.; McDowell, A.C.; Scholz, A.T.

    1991-01-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that would predict biological responses to reservoir operations as part of the System Operation Review program. Major components of the Lake Roosevelt model included: quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times. This report summarized the data collected on Lake Roosevelt for 1991 and includes limnological, zooplankton, benthic macroinvertebrate, fishery, and reservoir operation data. Discussions cover reservoir operation affect upon zooplankton, benthic macroinvertebrates, and fish. Reservoir operations brought reservoir elevations to a low of 1,221.7 in April, the result of power operations and a flood control shift from Dworshak Dam, in Idaho, to Grand Coulee Dam. Water retention times were correspondingly low reaching a minimum of 14.7 days on April 27th

  12. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations; 1991 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Janelle R.; McDowell, Amy C.; Scholz, Allan T.

    1995-08-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that would predict biological responses to reservoir operations as part of the System Operation Review program. Major components of the Lake Roosevelt model included: quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times. This report summarized the data collected on Lake Roosevelt for 1991 and includes limnological, zooplankton, benthic macroinvertebrate, fishery, and reservoir operation data. Discussions cover reservoir operation affect upon zooplankton, benthic macroinvertebrates, and fish. Reservoir operations brought reservoir elevations to a low of 1,221.7 in April, the result of power operations and a flood control shift from Dworshak Dam, in Idaho, to Grand Coulee Dam. Water retention times were correspondingly low reaching a minimum of 14.7 days on April 27th.

  13. [Summer Greenhouse Gases Exchange Flux Across Water-air Interface in Three Water Reservoirs Located in Different Geologic Setting in Guangxi, China].

    Science.gov (United States)

    Li, Jian-hong; Pu, Jun-bing; Sun, Ping-an; Yuan, Dao-xian; Liu, Wen; Zhang, Tao; Mo, Xue

    2015-11-01

    Due to special hydrogeochemical characteristics of calcium-rich, alkaline and DIC-rich ( dissolved inorganic carbon) environment controlled by the weathering products from carbonate rock, the exchange characteristics, processes and controlling factors of greenhouse gas (CO2 and CH4) across water-air interface in karst water reservoir show obvious differences from those of non-karst water reservoir. Three water reservoirs (Dalongdong reservoir-karst reservoir, Wulixia reservoir--semi karst reservoir, Si'anjiang reservoir-non-karst reservoir) located in different geologic setting in Guangxi Zhuang Autonomous Region, China were chosen to reveal characteristics and controlling factors of greenhouse gas exchange flux across water-air interface. Two common approaches, floating chamber (FC) and thin boundary layer models (TBL), were employed to research and contrast greenhouse gas exchange flux across water-air interface from three reservoirs. The results showed that: (1) surface-layer water in reservoir area and discharging water under dam in Dalongdong water reservoir were the source of atmospheric CO2 and CH4. Surface-layer water in reservoir area in Wulixia water reservoir was the sink of atmospheric CO2 and the source of atmospheric CH4, while discharging water under dam was the source of atmospheric CO2 and CH4. Surface-layer water in Si'anjiang water reservoir was the sink of atmospheric CO2 and source of atmospheric CH4. (2) CO2 and CH4 effluxes in discharging water under dam were much more than those in surface-layer water in reservoir area regardless of karst reservoir or non karst reservoir. Accordingly, more attention should be paid to the CO2 and CH4 emission from discharging water under dam. (3) In the absence of submerged soil organic matters and plants, the difference of CH4 effluxes between karst groundwater-fed reservoir ( Dalongdong water reservoir) and non-karst area ( Wulixia water reservoir and Si'anjiang water reservoir) was less. However, CO2

  14. Avoiding The Inevitable? Capacity Loss From Reservoir Sedimentation

    Science.gov (United States)

    Gray, John R.; Randle, Timothy J.; Collins, Kent L.

    2013-01-01

    The inexorable loss of capacity of the nation's reservoirs—sooner or later threatening water supplies for municipal, agricultural, and industrial uses—is but one of a number of deleterious effects wrought by sediment deposition. Trapped sediments can also damage or bury dam outlets, water intakes, and related infrastructure. Downstream effects of sediment capture and retention by reservoirs can include channel and habitat degradation and biotic alterations.

  15. Representing Reservoir Stratification in Land Surface and Earth System Models

    Science.gov (United States)

    Yigzaw, W.; Li, H. Y.; Leung, L. R.; Hejazi, M. I.; Voisin, N.; Payn, R. A.; Demissie, Y.

    2017-12-01

    A one-dimensional reservoir stratification modeling has been developed as part of Model for Scale Adaptive River Transport (MOSART), which is the river transport model used in the Accelerated Climate Modeling for Energy (ACME) and Community Earth System Model (CESM). Reservoirs play an important role in modulating the dynamic water, energy and biogeochemical cycles in the riverine system through nutrient sequestration and stratification. However, most earth system models include lake models that assume a simplified geometry featuring a constant depth and a constant surface area. As reservoir geometry has important effects on thermal stratification, we developed a new algorithm for deriving generic, stratified area-elevation-storage relationships that are applicable at regional and global scales using data from Global Reservoir and Dam database (GRanD). This new reservoir geometry dataset is then used to support the development of a reservoir stratification module within MOSART. The mixing of layers (energy and mass) in the reservoir is driven by eddy diffusion, vertical advection, and reservoir inflow and outflow. Upstream inflow into a reservoir is treated as an additional source/sink of energy, while downstream outflow represented a sink. Hourly atmospheric forcing from North American Land Assimilation System (NLDAS) Phase II and simulated daily runoff by ACME land component are used as inputs for the model over the contiguous United States for simulations between 2001-2010. The model is validated using selected observed temperature profile data in a number of reservoirs that are subject to various levels of regulation. The reservoir stratification module completes the representation of riverine mass and heat transfer in earth system models, which is a major step towards quantitative understanding of human influences on the terrestrial hydrological, ecological and biogeochemical cycles.

  16. Investigation of changes to the operation of Keenleyside Dam to reduce supersaturation of dissolved gases downstream

    International Nuclear Information System (INIS)

    Nunn, J.O.H.; Fidler, L.E.; Northcott, P.

    1993-01-01

    Keenlyside Dam is located on the Columbia River in southeast British Columbia. It impounds Arrow Lakes Reservoir, which has a live storage of 8.8 billion m 3 . The dam is used for flood control and to increase power generation in the USA. Recent field measurements have shown that the current operation of the dam often creates high levels of total gas pressure (TGP) downstream of the dam, with supersaturation levels occasionally reaching as high as 140%. It appeared that these increased levels were associated with the use of the spillway. High levels of dissolved gases may have adverse effects on aquatic life. Therefore, a comprehensive study was initiated to investigate ways of reducing TGP levels. The discharge facilities at the dam are described, along with the effects of dissolved gas supersaturation on fish. Current studies include measurement of field TGP levels, development of a model to predict TGP levels for different modes of operation of the discharge facilities, assessing the effects of TGP on different fish species at different life stages, field testing of the discharge facilities, and assessment of long-term impacts of various operating alternatives on the dam structures and equipment. Preliminary results indicate that the north low-level ports of the spillway increase the TGP level significantly less than the other two components of the discharge facilities. Current operating practice therefore maximizes use of the north ports within current operating limits. 9 refs., 4 figs

  17. Effect of longitudinal profile on the seismic anaysis of concrete gravity dams

    International Nuclear Information System (INIS)

    El-Nady, A.; Ghobarah, A.; Aziz, T.S.

    1992-01-01

    The traditional three-dimensional analysis of concrete gravity dams is expensive and very difficult. An alternate approach is to divide the dam into substructures. Each monolith is considered as a substructure and its degrees of freedom are reduced to those on the contact surfaces with the adjacent monoliths as well as a few Ritz vectors. Using this procedure high accuracy was achieved using a reasonable number of degrees of freedom. The analysis is carried out in the frequency domain to account for the frequency dependent parameters in the reservoir substructure. The procedure was tested and compared to typical three-dimensional analysis and was found to give high accuracy. A simplified cross section of gravity dams with different longitudinal profiles was studied using the substructuring procedure as well as a typical two-dimensional analysis. The results obtained show a significant variation in dynamic properties of the dam from that calculated assuming two-dimensional analysis. Furthermore, the response of the dam varies significantly when including the effect of longitudinal profile of the structure. It is concluded that the two-dimensional representation of the structure may substantially overestimate the response of the dam, depending on its longitudinal profile, especially when keyed joints are used in the construction. 13 refs., 5 figs., 4 tabs

  18. Design, construction and performance of the Oldman River Dam grout curtain

    Energy Technology Data Exchange (ETDEWEB)

    Hartmaier, H.; Davachi, M. [Acres International Ltd., Calgary, AB (Canada); Dharmawardene, W. [Alberta Environment, Edmonton, AB (Canada); Sinclair, B. [Acres International Ltd., Niagara Falls, ON (Canada)

    2002-07-01

    The 76 m high Oldman River Dam was constructed between 1986 and 1991 near Pincher Creek, Alberta to provide flow regulation and on-stream storage of water for multi-purpose use and irrigation services as well as hydroelectric development. The dam's main structure includes an earth- and rockfill dam, a low earthfill dyke 1500 m long, twin diversion/low level outlet tunnels, a gated spillways structure, and 2 drainage tunnels. A 1.3 km long, three-line grout curtain up to 100 m deep extends below the foundation of the dam and spillway. The grout curtain was built in undeformed Paleocene sedimentary rocks affected by stress relief due to river valley erosion. 80 per cent of the grout consumption was from bedrock structural features. Piezometers, slope indicators and flow measurement weirs were installed in the dam and abutment areas both during and after construction to monitor the performance of the grout curtain. Instrument readings indicate that the grout curtain is successfully preventing the transmission of reservoir pressures to the foundation beneath the downstream shell of the dam. The piezometric pressures downstream of the grout curtain are the same as they were in the foundation before impounding. A small amount of seepage has appeared at the end of the grout curtain at the eastern end of the abutment of the spillway but it is not considered to be significant. 3 refs., 4 figs.

  19. Dam construction as an engineering solution for water supply problem : environmental thrusts

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, A.H. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2004-09-01

    Water supply management and the potential impacts associated with engineering practices in water supply systems were examined. Global aspects of increasing water demand were presented and compared with populations, urbanization and water demand. Engineering practices in waterworks developments such as dam construction, river intakes, infiltration galleries, wells, boreholes and adits were also discussed. Construction of large dams and the problems associated with damming the rivers were studied as large dams generally have substantial impacts on rivers, watersheds and aquatic ecosystems, leading to the irreversible loss of species populations and ecosystems. These problems include negative impacts on the terrestrial ecosystem, greenhouse gas emissions from reservoirs due to decaying vegetation and carbon inflows from the catchment, changes in flow regimes, trapping of sediments and nutrients behind a dam, blocking migration of aquatic organisms, as well as negative impacts on flood plain ecosystems and fisheries. In addition, a case study, on the environmental impacts associated with damming in Three Gorges Valley in China was presented. 9 refs., 8 figs.

  20. Paddle River Dam : review of probable maximum flood

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D. [UMA Engineering Ltd., Edmonton, AB (Canada); Neill, C.R. [Northwest Hydraulic Consultants Ltd., Edmonton, AB (Canada)

    2008-07-01

    The Paddle River Dam was built in northern Alberta in the mid 1980s for flood control. According to the 1999 Canadian Dam Association (CDA) guidelines, this 35 metre high, zoned earthfill dam with a spillway capacity sized to accommodate a probable maximum flood (PMF) is rated as a very high hazard. At the time of design, it was estimated to have a peak flow rate of 858 centimetres. A review of the PMF in 2002 increased the peak flow rate to 1,890 centimetres. In light of a 2007 revision of the CDA safety guidelines, the PMF was reviewed and the inflow design flood (IDF) was re-evaluated. This paper discussed the levels of uncertainty inherent in PMF determinations and some difficulties encountered with the SSARR hydrologic model and the HEC-RAS hydraulic model in unsteady mode. The paper also presented and discussed the analysis used to determine incremental damages, upon which a new IDF of 840 m{sup 3}/s was recommended. The paper discussed the PMF review, modelling methodology, hydrograph inputs, and incremental damage of floods. It was concluded that the PMF review, involving hydraulic routing through the valley bottom together with reconsideration of the previous runoff modeling provides evidence that the peak reservoir inflow could reasonably be reduced by approximately 20 per cent. 8 refs., 5 tabs., 8 figs.

  1. Determination of metals in water from Billings dam, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante, E-mail: taoliveira@ipen.br, E-mail: jesarkis@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile, E-mail: lcbm@usp.br [Instituto de Pesca, (IP/SAA-SP), Sao Paulo, SP (Brazil). Secretaria da Agricultura e Abastecimento do Estado de Sao Paulo

    2013-07-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

  2. Determination of metals in water from Billings dam, Sao Paulo

    International Nuclear Information System (INIS)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante; Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile

    2013-01-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

  3. Underground dams for irrigation supplies in coastal limestone aquifer, Okinawa, Japan

    Science.gov (United States)

    Yasumoto, J.; Nakano, T.; Nawa, N.

    2011-12-01

    The use of underground dams to store water in regions with arid or tropical climates is a method that has received considerable attention in the last few decades. And now, for the tropical and subtropical islands that are highly vulnerable to climate change underground dams have been attracting attention again as a method of groundwater management. Okinawa Prefecture is Japan's southernmost prefecture, which consists of hundreds of islands in a chain over 1,000 km long, called the Ryukyu Islands which extend southwest from Kyushu to Taiwan. The national irrigation project of the Ryukyu Islands has been carried out, and several underground dams have been constructed. The Komesu and Giiza underground dams are first full scale underground dam facilities constructed for irrigation in Japan. The Komesu underground dam is a salt-water proof type. It prevents salt-water intrusion and provides storage fresh-water for irrigation in coastal limestone aquifer. Giiza underground dam is a dam up type for storage of fresh-water. These groundwater reservoirs are located in the coastal region of southern part of Okinawa (main island), where Ryukyu limestone is extensively distributed. We studied the behaviour of groundwater flow, saltwater intrusion and nitrate nitrogen (NO3-N) in groundwater in this region by using observation data of groundwater and springs through long term (from 1993 to 2010) monitoring. And, a groundwater flow and salt-water intrusion analysis have been conducted with three dimensional numerical model applied to these dam reservoir areas. The MODFLOW-NWT with SWI code and PEST was used to simulate the complex groundwater flow patterns. Through the comparison with simulation and observed data, it was concluded that the cut off wall of underground dams effectively stores the groundwater and prevents the salt-water intrusion in the reservoir areas. The observed groundwater levels at the reservoir areas were almost reproduced by the numerical model, but there

  4. Dams and Obstructions along Iowa's Canoe Routes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

  5. Douglas County Dam Breach Inundation Areas

    Data.gov (United States)

    Kansas Data Access and Support Center — Dam breach analysis provides a prediction of the extent and timing of flooding from a catastrophic breach of the dams. These results are sufficient for developing...

  6. Simulation of Breach Outflow for Earthfill Dam

    International Nuclear Information System (INIS)

    Razad, Azwin Zailti Abdul; Muda, Rahsidi Sabri; Sidek, Lariyah Mohd; Azia, Intan Shafilah Abdul; Mansor, Faezah Hanum; Yalit, Ruzaimei

    2013-01-01

    Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

  7. Technical bulletin : structural considerations for dam safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This technical bulletin discussed issues related to the safety assessment of concrete water-retaining structures and timber dams. Structures reviewed in the paper included gravity dams; buttress dams; arch dams; spillway structures; intake structures; power plants; roller compacted concrete dams; and timber dams. A variety of issues related to the loss of cohesive bond and discontinuities in bedrock foundations were reviewed with reference to issues related to compressive strength, tensile strength, and shear strength. Static failure modes and failure mechanisms related to dam failures were also described. Visual indicators for potential failures include abutment and foundation movement, seepage, and structure movements. Loading combinations were discussed, and performance indicators for gravity dams were provided. Methods of analysis for considering load characteristics, structure types and geological conditions were also discussed. Modelling techniques for finite element analysis were also included. 16 refs., 3 tabs., 5 figs.

  8. The Economic Benefits Of Multipurpose Reservoirs In The United States- Federal Hydropower Fleet

    Energy Technology Data Exchange (ETDEWEB)

    Hadjerioua, Boualem [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stewart, Kevin M. [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy (EERE); Bonnet Acosta, Marisol [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy (EERE); Mobley, Miles [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    The United States is home to over 80,000 dams, of which approximately 3% are equipped with hydroelectric generating capabilities. When a dam serves as a hydropower facility, it provides a variety of energy services that range from clean, reliable power generation to load balancing that supports grid stability. In most cases, the benefits of dams and their associated reservoirs go far beyond supporting the nation s energy demand. As evidenced by the substantial presence of non-powered dams with the ability to store water in large capacities, the primary purpose of a dam may not be hydropower, but rather one of many other purposes. A dam and reservoir may support navigation, recreation, flood control, irrigation, and water supply, with each multipurpose benefit providing significant social and economic impacts on a local, regional, and national level. When hydropower is one of the services provided by a multipurpose reservoir, it is then part of an integrated system of competing uses. Operating rules, management practices, consumer demands, and environmental constraints must all be balanced to meet the multipurpose project s objectives. When federal dams are built, they are authorized by Congress to serve one or more functions. Legislation such as the Water Resources Development Act regulates the operation of the facility in order to coordinate the authorized uses and ensure the dam s intended objectives are being met. While multipurpose reservoirs account for billions of dollars in contributions to National Economic Development (NED) every year, no attempt has been made to evaluate their benefits on a national scale. This study is an on-going work conducted by Oak Ridge National Laboratory in an effort to estimate the economic benefits of multipurpose hydropower reservoirs in the United States. Given the important role that federal hydropower plays in the U.S., the first focus of this research will target the three main federal hydropower owners Tennessee Valley

  9. 78 FR 53494 - Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams

    Science.gov (United States)

    2013-08-29

    ... Bar Dams AGENCY: Tennessee Valley Authority. ACTION: Issuance of Record of Decision. SUMMARY: This... the dam safety modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams. The notice of... Loudoun, Tellico, and Watts Bar Dams was published in the Federal Register on May 31, 2013. This...

  10. Geomorphic response of the Sandy River, Oregon, to removal of Marmot Dam

    Science.gov (United States)

    Major, Jon J.; O'Connor, Jim E.; Podolak, Charles J.; Keith, Mackenzie K.; Grant, Gordon E.; Spicer, Kurt R.; Pittman, Smokey; Bragg, Heather M.; Wallick, J. Rose; Tanner, Dwight Q.; Rhode, Abagail; Wilcock, Peter R.

    2012-01-01

    The October 2007 breaching of a temporary cofferdam constructed during removal of the 15-meter (m)-tall Marmot Dam on the Sandy River, Oregon, triggered a rapid sequence of fluvial responses as ~730,000 cubic meters (m3) of sand and gravel filling the former reservoir became available to a high-gradient river. Using direct measurements of sediment transport, photogrammetry, airborne light detection and ranging (lidar) surveys, and, between transport events, repeat ground surveys of the reservoir reach and channel downstream, we monitored the erosion, transport, and deposition of this sediment in the hours, days, and months following breaching of the cofferdam. Rapid erosion of reservoir sediment led to exceptional suspended-sediment and bedload-sediment transport rates near the dam site, as well as to elevated transport rates at downstream measurement sites in the weeks and months after breaching. Measurements of sediment transport 0.4 kilometers (km) downstream of the dam site during and following breaching show a spike in the transport of fine suspended sediment within minutes after breaching, followed by high rates of suspended-load and bedload transport of sand. Significant transport of gravel bedload past the measurement site did not begin until 18 to 20 hours after breaching. For at least 7 months after breaching, bedload transport rates just below the dam site during high flows remained as much as 10 times above rates measured upstream of the dam site and farther downstream. The elevated sediment load was derived from eroded reservoir sediment, which began eroding when a meters-tall knickpoint migrated about 200 m upstream in the first hour after breaching. Rapid knickpoint migration triggered vertical incision and bank collapse in unconsolidated sand and gravel, leading to rapid channel widening. Over the following days and months, the knickpoint migrated upstream more slowly, simultaneously decreasing in height and becoming less distinct. Within 7 months

  11. WinDAM C earthen embankment internal erosion analysis software

    Science.gov (United States)

    Two primary causes of dam failure are overtopping and internal erosion. For the purpose of evaluating dam safety for existing earthen embankment dams and proposed earthen embankment dams, Windows Dam Analysis Modules C (WinDAM C) software will simulate either internal erosion or erosion resulting f...

  12. EVALUASI KEAMANAN DAM JATILUHUR BERBASIS INDEKS RESIKO

    Directory of Open Access Journals (Sweden)

    Avazbek Ishbaev

    2014-12-01

    Full Text Available The dams have very important roles to agricultural activities. Especially, West Java with 240,000 hectares of agricultural land, needs a good dam structure that can be used sustainably. Jatiluhur dam in Purwakarta, West Java is one of big dams in Indonesia which has important rules not only for Purwakarta but also for Jakarta, Karawang and Bekasi residents. A study and observation about safety and dam stability is needed to prevent any damage. The purpose of this research were to identify parameters that influenced dam safety and to evaluate dam reliability based on index tools. Analysis was done using risk index tools. The result showed that the condition of the dam of Jatiluhur is still satisfied with indicators, "Idam"-750. The total index risk was 127.22 and the safety factor was 83.04 out of 100. Therefore, Jatiluhur dam could be classified as safe and no need for particular treatments. Jatiluhur dam can be operated in normal condition or abnormal condition with periodic monitoring. Keywords: dam safety, evaluation, Jatiluhur Dam, risk index tools

  13. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The paper reports on the conclusions of decennial and annual inspections of French dams. Dams surveillance is performed by the operators and consists in visual examinations and measurements. Concrete dams, in particular, always have more or less developed fissures with water sweating threw the concrete mass or the foundations. Old concrete often show low swelling phenomena which are measured too. (J.S.)

  14. 78 FR 62627 - Sam Rayburn Dam Rate

    Science.gov (United States)

    2013-10-22

    ..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No... Schedule SRD-08, Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative... ADMINISTRATION RATE SCHEDULE SRD-13 \\1\\ WHOLESALE RATES FOR HYDRO POWER AND ENERGY SOLD TO SAM RAYBURN DAM...

  15. A pragmatic method for estimating seepage losses for small reservoirs with application in rural India

    Science.gov (United States)

    Oblinger, Jennifer A.; Moysey, Stephen M. J.; Ravindrinath, Rangoori; Guha, Chiranjit

    2010-05-01

    SummaryThe informal construction of small dams to capture runoff and artificially recharge ground water is a widespread strategy for dealing with water scarcity. A lack of technical capacity for the formal characterization of these systems, however, is often an impediment to the implementation of effective watershed management practices. Monitoring changes in reservoir storage provides a conceptually simple approach to quantify seepage, but does not account for the losses occurring when seepage is balanced by inflows to the reservoir and the stage remains approximately constant. To overcome this problem we evaluate whether a physically-based volume balance model that explicitly represents watershed processes, including reservoir inflows, can be constrained by a limited set of data readily collected by non-experts, specifically records of reservoir stage, rainfall, and evaporation. To assess the impact of parameter non-uniqueness associated with the calibration of the non-linear model, we perform a Monte Carlo analysis to quantify uncertainty in the total volume of water contributed to the subsurface by the 2007 monsoon for a dam located in the Deccan basalts near the village of Salri in Madhya Pradesh, India. The Monte Carlo analysis demonstrated that subsurface losses from the reservoir could be constrained with the available data, but additional measurements are required to constrain reservoir inflows. Our estimate of seepage from the reservoir (7.0 ± 0.6 × 10 4 m 3) is 3.5 times greater than the recharge volume estimated by considering reservoir volume changes alone. This result suggests that artificial recharge could be significantly underestimated when reservoir inflows are not explicitly included in models. Our seepage estimate also accounts for about 11% of rainfall occurring upstream of the dam and is comparable in magnitude to natural ground water recharge, thereby indicating that the reservoir plays a significant role in the hydrology of this small

  16. Dam's design continues throughout construction

    Energy Technology Data Exchange (ETDEWEB)

    Lara E, R; Wulff, J G

    1979-11-01

    In spite of adverse site conditions, Arenal dam in Costa Rica was completed a year ahead of schedule. Historical data on local earthquake activity which was available in unusual detail reduced some uncertainties in design information. Other uncertainties regarding the complex foundation conditions were resolved as excavation and construction progressed.

  17. Impacts of large dams on the complexity of suspended sediment dynamics in the Yangtze River

    Science.gov (United States)

    Wang, Yuankun; Rhoads, Bruce L.; Wang, Dong; Wu, Jichun; Zhang, Xiao

    2018-03-01

    The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1-30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics "signal" becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River.

  18. Integrated Flood Forecast and Virtual Dam Operation System for Water Resources and Flood Risk Management

    Science.gov (United States)

    Shibuo, Yoshihiro; Ikoma, Eiji; Lawford, Peter; Oyanagi, Misa; Kanauchi, Shizu; Koudelova, Petra; Kitsuregawa, Masaru; Koike, Toshio

    2014-05-01

    While availability of hydrological- and hydrometeorological data shows growing tendency and advanced modeling techniques are emerging, such newly available data and advanced models may not always be applied in the field of decision-making. In this study we present an integrated system of ensemble streamflow forecast (ESP) and virtual dam simulator, which is designed to support river and dam manager's decision making. The system consists of three main functions: real time hydrological model, ESP model, and dam simulator model. In the real time model, the system simulates current condition of river basins, such as soil moisture and river discharges, using LSM coupled distributed hydrological model. The ESP model takes initial condition from the real time model's output and generates ESP, based on numerical weather prediction. The dam simulator model provides virtual dam operation and users can experience impact of dam control on remaining reservoir volume and downstream flood under the anticipated flood forecast. Thus the river and dam managers shall be able to evaluate benefit of priori dam release and flood risk reduction at the same time, on real time basis. Furthermore the system has been developed under the concept of data and models integration, and it is coupled with Data Integration and Analysis System (DIAS) - a Japanese national project for integrating and analyzing massive amount of observational and model data. Therefore it has advantage in direct use of miscellaneous data from point/radar-derived observation, numerical weather prediction output, to satellite imagery stored in data archive. Output of the system is accessible over the web interface, making information available with relative ease, e.g. from ordinary PC to mobile devices. We have been applying the system to the Upper Tone region, located northwest from Tokyo metropolitan area, and we show application example of the system in recent flood events caused by typhoons.

  19. Assessing Risks of Mine Tailing Dam Failures

    Science.gov (United States)

    Concha Larrauri, P.; Lall, U.

    2017-12-01

    The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

  20. Research on Safety Factor of Dam Slope of High Embankment Dam under Seismic Condition

    Directory of Open Access Journals (Sweden)

    Li Bin

    2015-01-01

    Full Text Available With the constant development of construction technology of embankment dam, the constructed embankment dam becomes higher and higher, and the embankment dam with its height over 200m will always adopt the current design criteria of embankment dam only suitable for the construction of embankment dam lower than 200m in height. So the design criteria of high embankment dam shall be improved. We shall calculate the stability and safety factors of dam slope of high embankment dam under different dam height, slope ratio and different seismic intensity based on ratio of safety margin, and clarify the change rules of stability and safety factors of dam slope of high embankment dam with its height over 200m. We calculate the ratio of safety margin of traditional and reliable method by taking the stable, allowable and reliability index 4.2 of dam slope of high embankment dam with its height over 200m as the standard value, and conduct linear regression for both. As a result, the conditions, where 1.3 is considered as the stability and safety factors of dam slope of high embankment dam with its height over 200m under seismic condition and 4.2 as the allowable and reliability index, are under the same risk control level.

  1. a Study on the Stability of Earth DAM Subjected to the Seismic Load

    Science.gov (United States)

    Qi, Jinghua; Che, Ailan; Ge, Xiurun

    For ensuring the earth dam's stability of Wangqingtuo reservoir when silt liquefaction happens during Tangshan earthquake, a large amount of laboratory soil tests and field measurements have been performed to obtain the mechanic properties of the soil and silt dynamic parameters. On the basis of the soil tests, the equivalent linear constitutive model is employed in the dynamic numerical simulation of the typical dam and the results indicate that the shear deformation is induced by the foundation liquefaction with the help of the geo-slope software. Moreover, the stability analysis is performed using the finite element elasto-plastic model that is considered the Mohr-Coulomb failure criteria to calculate the stability factor. The factors indicate the local instability would take place because of the shear action. At last, the measures are introduced to the designers for preventing the dam from the instability.

  2. Fortescue reservoir development and reservoir studies

    Energy Technology Data Exchange (ETDEWEB)

    Henzell, S.T.; Hicks, G.J.; Horden, M.J.; Irrgang, H.R.; Janssen, E.J.; Kable, C.W.; Mitchell, R.A.H.; Morrell, N.W.; Palmer, I.D.; Seage, N.W.

    1985-03-01

    The Fortescue field in the Gippsland Basin, offshore southeastern Australia is being developed from two platforms (Fortescue A and Cobia A) by Esso Australia Ltd. (operator) and BHP Petroleum. The Fortescue reservoir is a stratigraphic trap at the top of the Latrobe Group of sediments. It overlies the western flank of the Halibut and Cobia fields and is separated from them by a non-net sequence of shales and coals which form a hydraulic barrier between the two systems. Development drilling into the Fortescue reservoir commenced in April 1983 with production coming onstream in May 1983. Fortescue, with booked reserves of 44 stock tank gigalitres (280 million stock tank barrels) of 43/sup 0/ API oil, is the seventh major oil reservoir to be developed in the offshore Gippsland Basin by Esso/BHP. In mid-1984, after drilling a total of 20 exploration and development wells, and after approximately one year of production, a detailed three-dimensional, two-phase reservoir simulation study was performed to examine the recovery efficiency, drainage patterns, pressure performance and production rate potential of the reservoir. The model was validated by history matching an extensive suite of Repeat Formation Test (RFT) pressure data. The results confirmed the reserves basis, and demonstrated that the ultimate oil recovery from the reservoir is not sensitive to production rate. This result is consistent with studies on other high quality Latrobe Group reservoirs in the Gippsland Basin which contain undersaturated crudes and receive very strong water drive from the Basin-wide aquifer system. With the development of the simulation model during the development phase, it has been possible to more accurately define the optimal well pattern for the remainder of the development.

  3. Aging Reservoirs in a Changing Climate: Examining Storage Loss of Large Reservoirs and Variability of Sedimentation Rate in a Dominant Cropland Region

    Science.gov (United States)

    Rahmani, V.; Kastens, J.; deNoyelles, F.; Huggins, D.; Martinko, E.

    2015-12-01

    Dam construction has multiple environmental and hydrological consequences including impacts on upstream and downstream ecosystems, water chemistry, and streamflow. Behind the dam the reservoir can trap sediment from the stream and fill over time. With increasing population and drinking and irrigation water demands, particularly in the areas that have highly variable weather and extended drought periods such as the United States Great Plains, reservoir sedimentation escalates water management concerns. Under nearly all projected climate change scenarios we expect that reservoir water storage and management will come under intense scrutiny because of the extensive use of interstate river compacts in the Great Plains. In the state of Kansas, located in the Great Plains, bathymetric surveys have been completed during the last decade for many major lakes by the Kansas Biological Survey, Kansas Water Office, and the U.S. Army Corps of Engineers. In this paper, we studied the spatial and temporal changes of reservoir characteristics including sedimentation yield, depletion rate, and storage capacity loss for 24 federally-operated reservoirs in Kansas. These reservoirs have an average age of about 50 years and collectively have lost approximately 15% of their original capacity, with the highest annual observed single-reservoir depletion rate of 0.84% and sedimentation yield of 1,685 m3 km-2 yr-1.

  4. Evaluation of the Hydropower Generation Potential of a Dam Using Optimization Techniques: Application to Doma Dam, Nassarawa, in North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Salami Adebayo Wahab

    2017-03-01

    Full Text Available Optimization models have been developed to maximize annual energy generation from the Doma dam, subject to the constraint of releases for irrigation, ecological purposes, the water supply, the maximum yield from the reservoir and reservoir storage. The model was solved with LINGO software for various mean annual inflow exceedence probabilities. Two scenarios of hydropower retrofitting were considered. Scenario 1, with the reservoir inflows at 50%, 75%, and 90% probabilities of exceedence, gives the total annual hydropower as 0.531 MW, 0.450 MW and 0.291 MW, respectively. The corresponding values for scenario 2 were 0.615 MW, 0.507 MW, and 0.346 MW respectively. The study also considered increasing the reservoir’s live storage to 32.63Mm3 by taking part of the flood storage so that the maximum draft increases to 7 Mm3. With this upper limit of storage and draft with reservoir inflows of 50%, 75% and 90% probabilities of exceedence, the hydropower generated increased to 0.609 MW, 0.540 MW, and 0.347 MW respectively for the scenario 1 arrangement, while those of scenario 2 increased to 0.699 MW, 0.579MW and 0.406 MW respectively. The results indicate that the Doma Dam is suitable for the production of hydroelectric power and that its generation potential is between 0.61 MW and 0.70 MW.

  5. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...... dispersion equation in modeling the transport and the deposition of reservoir fines. It successfully predicts the unsymmetrical concentration profiles and the hyperexponential deposition in experiments....

  6. New guidelines for dam safety classification

    International Nuclear Information System (INIS)

    Dascal, O.

    1999-01-01

    Elements are outlined of recommended new guidelines for safety classification of dams. Arguments are provided for the view that dam classification systems should require more than one system as follows: (a) classification for selection of design criteria, operation procedures and emergency measures plans, based on potential consequences of a dam failure - the hazard classification of water retaining structures; (b) classification for establishment of surveillance activities and for safety evaluation of dams, based on the probability and consequences of failure - the risk classification of water retaining structures; and (c) classification for establishment of water management plans, for safety evaluation of the entire project, for preparation of emergency measures plans, for definition of the frequency and extent of maintenance operations, and for evaluation of changes and modifications required - the hazard classification of the project. The hazard classification of the dam considers, as consequence, mainly the loss of lives or persons in jeopardy and the property damages to third parties. Difficulties in determining the risk classification of the dam lie in the fact that no tool exists to evaluate the probability of the dam's failure. To overcome this, the probability of failure can be substituted for by a set of dam characteristics that express the failure potential of the dam and its foundation. The hazard classification of the entire project is based on the probable consequences of dam failure influencing: loss of life, persons in jeopardy, property and environmental damage. The classification scheme is illustrated for dam threatening events such as earthquakes and floods. 17 refs., 5 tabs

  7. Asymptotics of Wigner 3nj-symbols with small and large angular momenta: an elementary method

    International Nuclear Information System (INIS)

    Bonzom, Valentin; Fleury, Pierre

    2012-01-01

    Yu and Littlejohn recently studied in (2011 Phys. Rev. A 83 052114 (arXiv:1104.1499)) some asymptotics of Wigner symbols with some small and large angular momenta. They found that in this regime the essential information is captured by the geometry of a tetrahedron, and gave new formulae for 9j-, 12j- and 15j-symbols. We present here an alternative derivation which leads to a simpler formula, based on the use of the Ponzano–Regge formula for the relevant tetrahedron. The approach is generalized to Wigner 3nj-symbols with some large and small angular momenta, where more than one tetrahedron are needed, leading to new asymptotics for Wigner 3nj-symbols. As an illustration, we present 15j-symbols with one, two and four small angular momenta, and give an alternative formula to Yu’s recent 15j-symbol with three small spins. (paper)

  8. Nonlinear Filtering Effects of Reservoirs on Flood Frequency Curves at the Regional Scale: RESERVOIRS FILTER FLOOD FREQUENCY CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Li, Hong-Yi; Leung, Lai-Yung; Yigzaw, Wondmagegn Y.; Zhao, Jianshi; Lu, Hui; Deng, Zhiqun; Demissie, Yonas; Bloschl, Gunter

    2017-10-01

    Anthropogenic activities, e.g., reservoir operation, may alter the characteristics of Flood Frequency Curve (FFC) and challenge the basic assumption of stationarity used in flood frequency analysis. This paper presents a combined data-modeling analysis of the nonlinear filtering effects of reservoirs on the FFCs over the contiguous United States. A dimensionless Reservoir Impact Index (RII), defined as the total upstream reservoir storage capacity normalized by the annual streamflow volume, is used to quantify reservoir regulation effects. Analyses are performed for 388 river stations with an average record length of 50 years. The first two moments of the FFC, mean annual maximum flood (MAF) and coefficient of variations (CV), are calculated for the pre- and post-dam periods and compared to elucidate the reservoir regulation effects as a function of RII. It is found that MAF generally decreases with increasing RII but stabilizes when RII exceeds a threshold value, and CV increases with RII until a threshold value beyond which CV decreases with RII. The processes underlying the nonlinear threshold behavior of MAF and CV are investigated using three reservoir models with different levels of complexity. All models capture the non-linear relationships of MAF and CV with RII, suggesting that the basic flood control function of reservoirs is key to the non-linear relationships. The relative roles of reservoir storage capacity, operation objectives, available storage prior to a flood event, and reservoir inflow pattern are systematically investigated. Our findings may help improve flood-risk assessment and mitigation in regulated river systems at the regional scale.

  9. Research on shape optimization of CSG dams

    Directory of Open Access Journals (Sweden)

    Xin Cai

    2011-12-01

    Full Text Available The multi-objective optimization method was used for shape optimization of cement sand and gravel (CSG dams in this study. The economic efficiency, the sensitivities of maximum horizontal displacement and maximum settlement of the dam to water level changes, the overall stability, and the overall strength security were taken into account during the optimization process. Three weight coefficient selection schemes were adopted to conduct shape optimization of a dam, and the case studies lead to the conclusion that both the upstream and downstream dam slope ratios for the optimal cross-section equal 1:0.7, which is consistent with the empirically observed range of 1:0.6 to 1:0.8 for the upstream and downstream dam slope ratios of CSG dams. Therefore, the present study is of certain reference value for designing CSG dams.

  10. Geophysical investigations of geology and structure at the Martis Creek Dam, Truckee, California

    Science.gov (United States)

    Bedrosian, P.A.; Burton, B.L.; Powers, M.H.; Minsley, B.J.; Phillips, J.D.; Hunter, L.E.

    2012-01-01

    A recent evaluation of Martis Creek Dam highlighted the potential for dam failure due to either seepage or an earthquake on nearby faults. In 1972, the U.S. Army Corps of Engineers constructed this earthen dam, located within the Truckee Basin to the north of Lake Tahoe, CA for water storage and flood control. Past attempts to raise the level of the Martis Creek Reservoir to its design level have been aborted due to seepage at locations downstream, along the west dam abutment, and at the base of the spillway. In response to these concerns, the U.S. Geological Survey has undertaken a comprehensive suite of geophysical investigations aimed at understanding the interplay between geologic structure, seepage patterns, and reservoir and groundwater levels. This paper concerns the geologic structure surrounding Martis Creek Dam and emphasizes the importance of a regional-scale understanding to the interpretation of engineering-scale geophysical data. Our studies reveal a thick package of sedimentary deposits interbedded with Plio-Pleistocene volcanic flows; both the deposits and the flows are covered by glacial outwash. Magnetic field data, seismic tomography models, and seismic reflections are used to determine the distribution and chronology of the volcanic flows. Previous estimates of depth to basement (or the thickness of the interbedded deposits) was 100 m. Magnetotelluric soundings suggest that electrically resistive bedrock may be up to 2500 m deep. Both the Polaris Fault, identified outside of the study area using airborne LiDAR, and the previously unnamed Martis Creek Fault, have been mapped through the dam area using ground and airborne geophysics. Finally, as determined by direct-current resistivity imaging, time-domain electromagnetic sounding, and seismic refraction, the paleotopography of the interface between the sedimentary deposits and the overlying glacial outwash plays a principal role both in controlling groundwater flow and in the distribution of the

  11. Repair Works for Uplift and Seepage Control in Existing Concrete Dams

    Science.gov (United States)

    1989-08-01

    weathered and therefore where the presence of soil mterials is likely to occur in joints and fractures. Fig.5 - Varosa dam. Main results of mechanical...situations are associated with: emptying of reservoir by hot summer; water effects due to hydrostatic pressure and uplift; winter, spring and autumn...design stage were supported by tests of three-dimensional plaster- diatomite models, carried out at LNEC (1971c). The models were built in a scale of 1

  12. Dam-Breach hydrology of the Johnstown flood of 1889-challenging the findings of the 1891 investigation report.

    Science.gov (United States)

    Coleman, Neil M; Kaktins, Uldis; Wojno, Stephanie

    2016-06-01

    In 1891 a report was published by an ASCE committee to investigate the cause of the Johnstown flood of 1889. They concluded that changes made to the dam by the South Fork Fishing and Hunting Club did not cause the disaster because the embankment would have been overflowed and breached if the changes were not made. We dispute that conclusion based on hydraulic analyses of the dam as originally built, estimates of the time of concentration and time to peak for the South Fork drainage basin, and reported conditions at the dam and in the watershed. We present a LiDAR-based volume of Lake Conemaugh at the time of dam failure (1.455 × 10(7) m(3)) and hydrographs of flood discharge and lake stage decline. Our analytical approach incorporates the complex shape of this dam breach. More than 65 min would have been needed to drain most of the lake, not the 45 min cited by most sources. Peak flood discharges were likely in the range 7200 to 8970 m(3) s(-1). The original dam design, with a crest ∼0.9 m higher and the added capacity of an auxiliary spillway and five discharge pipes, had a discharge capacity at overtopping more than twice that of the reconstructed dam. A properly rebuilt dam would not have overtopped and would likely have survived the runoff event, thereby saving thousands of lives. We believe the ASCE report represented state-of-the-art for 1891. However, the report contains discrepancies and lapses in key observations, and relied on excessive reservoir inflow estimates. The confidence they expressed that dam failure was inevitable was inconsistent with information available to the committee. Hydrodynamic erosion was a likely culprit in the 1862 dam failure that seriously damaged the embankment. The Club's substandard repair of this earlier breach sowed the seeds of its eventual destruction.

  13. Development of Probabilistic Flood Inundation Mapping For Flooding Induced by Dam Failure

    Science.gov (United States)

    Tsai, C.; Yeh, J. J. J.

    2017-12-01

    A primary function of flood inundation mapping is to forecast flood hazards and assess potential losses. However, uncertainties limit the reliability of inundation hazard assessments. Major sources of uncertainty should be taken into consideration by an optimal flood management strategy. This study focuses on the 20km reach downstream of the Shihmen Reservoir in Taiwan. A dam failure induced flood herein provides the upstream boundary conditions of flood routing. The two major sources of uncertainty that are considered in the hydraulic model and the flood inundation mapping herein are uncertainties in the dam break model and uncertainty of the roughness coefficient. The perturbance moment method is applied to a dam break model and the hydro system model to develop probabilistic flood inundation mapping. Various numbers of uncertain variables can be considered in these models and the variability of outputs can be quantified. The probabilistic flood inundation mapping for dam break induced floods can be developed with consideration of the variability of output using a commonly used HEC-RAS model. Different probabilistic flood inundation mappings are discussed and compared. Probabilistic flood inundation mappings are hoped to provide new physical insights in support of the evaluation of concerning reservoir flooded areas.

  14. A Framework to Assess the Cumulative Hydrological Impacts of Dams on flow Regime

    Science.gov (United States)

    Wang, Y.; Wang, D.

    2016-12-01

    In this study we proposed a framework to assess the cumulative impact of dams on hydrological regime, and the impacts of the Three Gorges Dam on flow regime in Yangtze River were investigated with the framework. We reconstructed the unregulated flow series to compare with the regulated flow series in the same period. Eco-surplus and eco-deficit and the Indicators of Hydrologic Alteration parameters were used to examine the hydrological regime change. Among IHA parameters, Wilcoxon signed-rank test and Principal Components Analysis identified the representative indicators of hydrological alterations. Eco-surplus and eco-deficit showed that the reservoir also changed the seasonal regime of the flows in autumn and winter. Annual extreme flows and October flows changes lead to negative ecological implications downstream from the Three Gorges Dam. Ecological operation for the Three Gorges Dam is necessary to mitigate the negative effects on the river ecosystem in the middle reach of Yangtze River. The framework proposed here could be a robust method to assess the cumulative impacts of reservoir operation.

  15. Investigating Efficiency of Vector-Valued Intensity Measures in Seismic Demand Assessment of Concrete Dams

    Directory of Open Access Journals (Sweden)

    Mohammad Alembagheri

    2018-01-01

    Full Text Available The efficiency of vector-valued intensity measures for predicting the seismic demand in gravity dams is investigated. The Folsom gravity dam-reservoir coupled system is selected and numerically analyzed under a set of two-hundred actual ground motions. First, the well-defined scalar IMs are separately investigated, and then they are coupled to form two-parameter vector IMs. After that, IMs consisting of spectral acceleration at the first-mode natural period of the dam-reservoir system along with a measure of the spectral shape (the ratio of spectral acceleration at a second period to the first-mode spectral acceleration value are considered. It is attempted to determine the optimal second period by categorizing the spectral acceleration at the first-mode period of vibration. The efficiency of the proposed vector IMs is compared with scalar ones considering various structural responses as EDPs. Finally, the probabilistic seismic behavior of the dam is investigated by calculating its fragility curves employing scalar and vector IMs considering the effect of zero response values.

  16. Large-scale dam removal on the Elwha River, Washington, USA: source-to-sink sediment budget and synthesis

    Science.gov (United States)

    Warrick, Jonathan A.; Bountry, Jennifer A.; East, Amy E.; Magirl, Christopher S.; Randle, Timothy J.; Gelfenbaum, Guy R.; Ritchie, Andrew C.; Pess, George R.; Leung, Vivian; Duda, Jeff J.

    2015-01-01

    Understanding landscape responses to sediment supply changes constitutes a fundamental part of many problems in geomorphology, but opportunities to study such processes at field scales are rare. The phased removal of two large dams on the Elwha River, Washington, exposed 21 ± 3 million m3, or ~ 30 million tonnes (t), of sediment that had been deposited in the two former reservoirs, allowing a comprehensive investigation of watershed and coastal responses to a substantial increase in sediment supply. Here we provide a source-to-sink sediment budget of this sediment release during the first two years of the project (September 2011–September 2013) and synthesize the geomorphic changes that occurred to downstream fluvial and coastal landforms. Owing to the phased removal of each dam, the release of sediment to the river was a function of the amount of dam structure removed, the progradation of reservoir delta sediments, exposure of more cohesive lakebed sediment, and the hydrologic conditions of the river. The greatest downstream geomorphic effects were observed after water bodies of both reservoirs were fully drained and fine (silt and clay) and coarse (sand and gravel) sediments were spilling past the former dam sites. After both dams were spilling fine and coarse sediments, river suspended-sediment concentrations were commonly several thousand mg/L with ~ 50% sand during moderate and high river flow. At the same time, a sand and gravel sediment wave dispersed down the river channel, filling channel pools and floodplain channels, aggrading much of the river channel by ~ 1 m, reducing river channel sediment grain sizes by ~ 16-fold, and depositing ~ 2.2 million m3 of sand and gravel on the seafloor offshore of the river mouth. The total sediment budget during the first two years revealed that the vast majority (~ 90%) of the sediment released from the former reservoirs to the river passed through the fluvial system and was discharged to the coastal

  17. Freshwater fish Fauna and Restock Fish Activities of Reservoir in the Dardanelles (Canakkale-Turkey

    Directory of Open Access Journals (Sweden)

    Hüseyin SASI

    2012-06-01

    Full Text Available Turkey has, with geographic location including Istanbul and Çanakkale straits the system, 178,000 km in length streams, 906,000 ha of natural lakes, and 411,800 ha of dam lakes, and 28,000 ha of ponds due to richness inland waters which include freshwater fish. The fingerling fish (fry were restocked approximately 250,000,000 in natural lakes, dam lakes and ponds for fisheries between years of 1979 and 2005. Canakkale has rich freshwater potential with 7 major rivers (Büyükdere, Karamenderes stream, Kavak brook, Kocacay stream, Sarıcay stream, Tuzla brook, Umurbey brook, 7 Dam Lakes (Atikhisar, Zeytinlikoy, Bayramic, Bakacak, Tayfur, Umurbey and Yenice-Gönen Dam lakes. In the studies, it has been determined that 15 fish species belonging to 6 families (Anguillidae, Atherinidae, Salmonidae, Cobitidae, Cyprinidae and Poecilidae can be found in reservoirs. Fish restocking of the activities of the reservoir until today approximately 1,120,000 (Cyprinus carpio L., 1758 is introduced. In this study, the activity of Canakkale province in the fish restocking and reservoir exploiting possibilities were discussed in view of reservoir fisheries potential which is used insufficiently today.

  18. Nitrogen transport, transformation, and retention in the Three Gorges Reservoir : A mass balance approach

    NARCIS (Netherlands)

    Ran, Xiangbin; Bouwman, Lex; Yu, Zhigang; Beusen, Arthur; Chen, Hongtao; Yao, Qingzhen

    2017-01-01

    Dam construction in river systems affects the biogeochemistry of nitrogen (N), yet most studies on N cycling in reservoirs do not consider the transformations and retention of the different N species. This study addresses the N inputs, transport, transformations, and retention in the Three Gorges

  19. Proceedings of the 2010 Canadian Dam Association's public safety around dams workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Nearly 30 people have drowned in dam-related incidents over the last 10 years in Canada. The Canadian public is now calling for improved safety guidelines. Public interaction with dams is increasing as a result of interest in extreme sports and perceived rights of access. However, many members of the public are not aware of the dangers posed by dams. This workshop provided a forum to discuss proposals for a draft publication of the Canadian Dam Association (CDA) guidelines for public safety and security around dams. Issues related to current legislation and liability were discussed. Methods of increasing public awareness of the hazards posed by dams included increased signage in dam locations, the use of audible and visual alert systems, and the use of booms and buoys. The responsibilities of dam owners in ensuring the safety of dams were also discussed. The conference featured 5 presentations, of which 2 have been catalogued separately for inclusion in this database. tabs., figs.

  20. Study of Dam-break Due to Overtopping of Four Small Dams in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Zakaraya Alhasan

    2015-01-01

    Full Text Available Dam-break due to overtopping is one of the most common types of embankment dam failures. During the floods in August 2002 in the Czech Republic, several small dams collapsed due to overtopping. In this paper, an analysis of the dam break process at the Luh, Velký Bělčický, Melín, and Metelský dams breached during the 2002 flood is presented. Comprehensive identification and analysis of the dam shape, properties of dam material and failure scenarios were carried out after the flood event to assemble data for the calibration of a numerical dam break model. A simple one-dimensional mathematical model was proposed for use in dam breach simulation, and a computer code was compiled. The model was calibrated using the field data mentioned above. Comparison of the erodibility parameters gained from the model showed reasonable agreement with the results of other authors.

  1. Influence of limnological zones on the spatial distribution of fish assemblages in three Brazilian reservoirs

    Directory of Open Access Journals (Sweden)

    Bárbara Becker

    2015-09-01

    Full Text Available Reservoirs can have both positive and negative effects on differing fish species depending on the species concerned and reservoir morphology, flow regime, and basin location.  We assessed the influence of limnological zones on the ichthyofauna of three large Neotropical reservoirs in two different river basins. We sampled fish through use of gill nets set at 40 systematically selected sites on each reservoir. We used satellite images, algae, and suspended solids concentrations to classify those sites as lacustrine or riverine. We observed significant differences in assemblage composition between riverine and lacustrine zones of each reservoir. We either tested if the same region (lacustrine or riverine showed the same patterns in different reservoirs. In São Simão, the riverine zone produced greater abundances of native species, long-distance migratory species, diversity, and richness, whereas the lacustrine zone supported greater total and non-native species abundances. Conversely, in Três Marias, the riverine zone supported greater total and non-native species abundances, whereas the others traits evaluated did not differ significantly between zones. Only lacustrine sites occurred in Volta Grande Reservoir. The same zones in the three reservoirs usually had significantly different patterns in the traits evaluated. The differences in spatial patterns observed between reservoirs could be explained partly by the differing morphologies (complex versus linear, the differential influence of tributaries of each reservoir and basin positions (presence or absence of upstream dams of the reservoirs.

  2. Methane Ebullition in Temperate Hydropower Reservoirs and Implications for US Policy on Greenhouse Gas Emissions.

    Science.gov (United States)

    Miller, Benjamin L; Arntzen, Evan V; Goldman, Amy E; Richmond, Marshall C

    2017-10-01

    The United States is home to 2198 dams actively used for hydropower production. With the December 2015 consensus adoption of the United Nations Framework Convention on Climate Change Paris Agreement, it is important to accurately quantify anthropogenic greenhouse gas emissions. Methane ebullition, or methane bubbles originating from river or lake sediments, has been shown to account for nearly all methane emissions from tropical hydropower reservoirs to the atmosphere. However, distinct ebullitive methane fluxes have been studied in comparatively few temperate hydropower reservoirs globally. This study measures ebullitive and diffusive methane fluxes from two eastern Washington reservoirs, and synthesizes existing studies of methane ebullition in temperate, boreal, and tropical hydropower reservoirs. Ebullition comprises nearly all methane emissions (>97%) from this study's two eastern Washington hydropower reservoirs to the atmosphere. Summer methane ebullition from these reservoirs was higher than ebullition in six southeastern U.S. hydropower reservoirs, however it was similar to temperate reservoirs in other parts of the world. Our literature synthesis suggests that methane ebullition from temperate hydropower reservoirs can be seasonally elevated compared to tropical climates, however annual emissions are likely to be higher within tropical climates, emphasizing the possible range of methane ebullition fluxes and the need for the further study of temperate reservoirs. Possible future changes to the Intergovernmental Panel on Climate Change and UNFCCC guidelines for national greenhouse gas inventories highlights the need for accurate assessment of reservoir emissions.

  3. Methane Ebullition in Temperate Hydropower Reservoirs and Implications for US Policy on Greenhouse Gas Emissions

    Science.gov (United States)

    Miller, Benjamin L.; Arntzen, Evan V.; Goldman, Amy E.; Richmond, Marshall C.

    2017-10-01

    The United States is home to 2198 dams actively used for hydropower production. With the December 2015 consensus adoption of the United Nations Framework Convention on Climate Change Paris Agreement, it is important to accurately quantify anthropogenic greenhouse gas emissions. Methane ebullition, or methane bubbles originating from river or lake sediments, has been shown to account for nearly all methane emissions from tropical hydropower reservoirs to the atmosphere. However, distinct ebullitive methane fluxes have been studied in comparatively few temperate hydropower reservoirs globally. This study measures ebullitive and diffusive methane fluxes from two eastern Washington reservoirs, and synthesizes existing studies of methane ebullition in temperate, boreal, and tropical hydropower reservoirs. Ebullition comprises nearly all methane emissions (>97%) from this study's two eastern Washington hydropower reservoirs to the atmosphere. Summer methane ebullition from these reservoirs was higher than ebullition in six southeastern U.S. hydropower reservoirs, however it was similar to temperate reservoirs in other parts of the world. Our literature synthesis suggests that methane ebullition from temperate hydropower reservoirs can be seasonally elevated compared to tropical climates, however annual emissions are likely to be higher within tropical climates, emphasizing the possible range of methane ebullition fluxes and the need for the further study of temperate reservoirs. Possible future changes to the Intergovernmental Panel on Climate Change and UNFCCC guidelines for national greenhouse gas inventories highlights the need for accurate assessment of reservoir emissions.

  4. Management of dams for the next Millennium: proceedings of the 1999 Canadian Dam Association

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The meeting featured seven sessions with 18 papers abstracted/indexed therein as follows: keynote address: tailings dams safety - implications for the dam safety community; 1 - design and performance: performance monitoring of dams: are we doing what we should be doing?; tailings dams from the perspective of conventional dam engineering; and design overview of Syncrude's Mildred Lake east toe berm; 2 - design and modelling: use of a 2D model for a dam break study on the ALCAN hydroelectric complex in Quebec; and spillway design implications resulting from changes in rainfall extremes; 3 - risk and dam safety I: closing the gaps in the dam safety guidelines; the reality of life safety consequence classification; and surveillance practices for the next millenium; 4 - risk and dam safety II: quantitative risk-assessment using the capacity-demand analysis; and new guidelines for dam safety classification; 5 - millenium issues: expectations of immortality, dam safety management into the next millenium; 6 - rehabilitation techniques: the unconventional application of conventional materials; nondestructive testing technology to characterize concrete dam/bedrock interface; method and instrument for detecting crack in concrete; and grouting of the cracks in the Arch 5-6 - Daniel Johnson Dam; and 7 - case studies: rehabilitation of an 80 year old Ambursen type dam; and debris booms for the protection of spillways.

  5. GC51D-0831: A Study of the Impact of Dams on Sediment Retention in the Mekong River Basin

    Science.gov (United States)

    Munroe, Thailynn; Griffin, Robert; Anderson, Eric; Markert, Kel

    2017-01-01

    Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. The focus of this study is to utilize the Soil Water Assessment Tool (SWAT), developed at Texas A & M, a rainfall-runoff hydrologic model to determine change in sedimentation in the Mekong Basin after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu & Varis (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

  6. Investigation on the temperature of the asphalt-concrete facing of embankment dams

    Directory of Open Access Journals (Sweden)

    Karel Adam

    2016-01-01

    Full Text Available Asphalt concrete is a traditional material used for the constructions of upstream sealing of reservoir dams, particularly in upper reservoirs of pumped storage hydroelectric plants. The asphalt layer is often exposed to significant fluctuations of temperature caused, for example, by heating the facing from the sun and by its subsequent rapid cooling by water during reservoir periodical filling. To better understand the physical phenomena and behaviour of the facing in terms of vapour diffusion, the state of stress, etc., it is necessary to know temperature phenomena in the asphalt facing. This paper describes the measurement of temperature in the asphalt facing of the Dlouhe Strane pumped storage hydroelectric plant and its evaluation using 1D numerical model of heat flow in the asphalt concrete facing. Numerical simulation for selected load scenarios enabled the temperature phenomena that take place in the construction of the asphalt-concrete facing to be quantified. The analysis shows that during insolation, the asphalt facing is exposed to the significant temperature rise on its surface and also over its whole thickness. Similarly during frost weather the facing becomes frozen in its entire thickness. During the day cycle the temperature in the asphalt layers changes significantly. However, the temperature in the underlying rockfill dam body becomes steady approximately at the depth of 1.0 m. Keywords: Asphalt concrete facing, Temperature distribution analysis, Embankment dam

  7. Seismic Performance Evaluation of Concrete Gravity Dams with Penetrated Cracks Considering Fluid–Structure Interaction

    Directory of Open Access Journals (Sweden)

    A. Behshad

    2018-02-01

    Full Text Available In this paper, a comprehensive study on the seismic behavior of fractured concrete gravity dams during ground shakings is carried out considering dam–reservoir interaction effects. To gain the seismic behavior of the whole system, finite and boundary elements are employed to model the liquid region and the cracked structure, respectively. Formulation and different computational aspects of the suggested staggered hybrid approach are thoroughly argued. A computer code was developed in order to discuss the presented hybrid BE–DE technique and comparisons are made between the obtained results and those reported in the literature. To gain this goal, several problems of seismic excitations in frequency- and time-domains are presented employing the proposed approach, showing that the present results agree well with the results from other numerical procedures. The cracked Koyna Dam is scrutinized, considering the dynamic interaction between dam and reservoir with focus on the nonlinear behavior due to its top profile crack. The developed numerical model is rigorously validated by extensive comparisons with available results in the literature in which the dam–reservoir interaction were simplified by added masses. It can be concluded that there is significant disparity between the overturning and sliding response schemes of the nonlinear analysis and those of added mass technique.

  8. Status of Burbot (Lota lota) in Arrow Lakes Reservoir

    International Nuclear Information System (INIS)

    Arndt, S.; Baxter, J.

    2006-03-01

    Burbot populations at a water reservoir were assessed in order to examine the operational impacts of a hydro-electric dam in British Columbia. The study assessed the distribution, relative abundance, size, and age structure of the Burbot population. Spawning locations were evaluated, and an underwater camera was used to make population estimates. The distribution of burbot was determined using data derived from set line sampling catches conducted in 1995. The surveys indicated that the burbot were widely distributed throughout the reservoir. The burbots were larger than burbots seen in other lakes, and the age structure showed evidence of dominant and weak cohorts. Average growth rates were higher than most other populations in the province. Fish monitored in a radio-tagging experiment were located in various spawning areas in the vicinity of the reservoir. It was concluded that no aggregations of spawning burbot were observed in the narrows where an underwater video camera was installed. 31 refs., 5 tabs., 12 figs

  9. Williston Reservoir: Site preparation and post-flood cleanup

    International Nuclear Information System (INIS)

    Loose, J.A.

    1990-01-01

    Williston Reservoir is the second largest in Canada and ranks ninth on the world scale. It was formed by the construction of the W.A.C. Bennet Dam and is the most important hydroelectric storage reservoir and largest body of fresh water in British Columbia. Site preparation for the reservoir began in 1962, with pre-flood clearing involving salvage of merchantable timber, handfalling, machine downing, burning of slash and burial. Post-flood cleanup included timber salvage, bailing and burning debris, tractor piling and burning, crane piling in shallows, underwater cutting, and hand cutting during low drawdown. Various types of floating debris have presented problems for recreational use, log booming and transport, waterways and aviation. Protection of the spillway is accomplished with a floating boom upstream of the channel. Administration, funding, forest clearance, salvage methods, clearing standards, wood volumes, project costs, environmental concerns, and future priorities are discussed. 5 figs., 2 tabs

  10. Crotch Lake dam rehabilitation project

    International Nuclear Information System (INIS)

    Brunet, G.; Dobrowolski, E.

    1999-01-01

    Replacement of the existing wood crib dam structure on Crotch Lake on the Mississippi River in eastern Ontario that provided water storage for the power production at High Falls Generating Station, became necessary when it was determined that the dam did not meet Ontario-Hydro's safety standards. This paper describes the project of replacing the existing structure with a PVC coated gabion wall with waterproofing. The entire structure was covered with three layers of wire mesh, laced together, and criss-crossed for superior strength and rigidity. The work was completed in 28 days with no environmental impact . Life expectancy of the new structure is in excess of 40 years. With periodic maintenance of the gabion mat cover, life span could be extended an additional 20 to 40 years. 5 figs

  11. Coupled models in dam engineering

    OpenAIRE

    González Gutiérrez, María De Los Ángeles

    2016-01-01

    Rock ll dams are certainly one of the most important engineering structures due to their economic advantages and exible design. Unfortunately their vulnerability to overtopping still remains their weakest point. For that reason, several research groups are interested in both the numerical and experimental analysis of this phenomenon. In this work we focused on the numerical analysis. The previous work developed in CIMNE on a coupled PFEM-Eulerian free surface Compu- tational...

  12. Environmental monitoring at Olympic Dam

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    The environmental management and protection program at the Olympic Dam uranium/copper/gold project, Roxby Downs, South Australia, monitors eight major environmental parameters - meteorology, vegetation, mine site rehabilitation, fauna, terrain, soil salinity, hydrogeology and well fields. It came into effect with the approval of the South Australian Government in March 1987. The Great Artesian Basin, one of the world's greatest artesian basins, is the source of the water supply for the project

  13. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  14. Mitigating Dam Impacts Using Environmental Flow Releases

    Science.gov (United States)

    Richter, B. D.

    2017-12-01

    One of the most ecologically disruptive impacts of dams is their alteration of natural river flow variability. Opportunities exist for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. This presentation will highlight a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the suggested strategies for dam re-operation are predicated on changes in the end-use of the water, such as reductions in urban or agricultural water use during droughts, a systemic perspective of entire water management systems will be required to attain the fullest possible

  15. Detecting the leakage source of a reservoir using isotopes.

    Science.gov (United States)

    Yi, Peng; Yang, Jing; Wang, Yongdong; Mugwanezal, Vincent de Paul; Chen, Li; Aldahan, Ala

    2018-07-01

    A good monitoring method is vital for understanding the sources of a water reservoir leakage and planning for effective restoring. Here we present a combination of several tracers ( 222 Rn, oxygen and hydrogen isotopes, anions and temperature) for identification of water leakage sources in the Pushihe pumped storage power station which is in the Liaoning province, China. The results show an average 222 Rn activity of 6843 Bq/m 3 in the leakage water, 3034 Bq/m 3 in the reservoir water, and 41,759 Bq/m 3 in the groundwater. Considering that 222 Rn activity in surface water is typically less than 5000 Bq/m 3 , the low level average 222 Rn activity in the leakage water suggests the reservoir water as the main source of water. Results of the oxygen and hydrogen isotopes show comparable ranges and values in the reservoir and the leakage water samples. However, important contribution of the groundwater (up to 36%) was present in some samples from the bottom and upper parts of the underground powerhouse, while the leakage water from some other parts indicate the reservoir water as the dominant source. The isotopic finding suggests that the reservoir water is the main source of the leakage water which is confirmed by the analysis of anions (nitrate, sulfate, and chloride) in the water samples. The combination of these tracer methods for studying dam water leakage improves the accuracy of identifying the source of leaks and provide a scientific reference for engineering solutions to ensure the dam safety. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Mitigation for the Construction and Operation of Libby Dam, 2001-2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Dunnigan, James L.; Marotz, Brian L.; DeShazer, Jay (Montana Department of Fish, Wildlife and Parks, Libby, MT)

    2003-06-01

    Libby Reservoir was created under an International Columbia River Treaty between the United States and Canada for cooperative water development of the Columbia River Basin (Columbia River Treaty 1964). Libby Reservoir inundated 109 stream miles of the mainstem Kootenai River in the United States and Canada, and 40 miles of tributary streams in the U.S. that provided habitat for spawning, juvenile rearing, and migratory passage (Figure 1). The authorized purpose of the dam is to provide power (91.5%), flood control (8.3%), and navigation and other benefits (0.2%; Storm et al. 1982). The Pacific Northwest Power Act of 1980 recognized possible conflicts stemming from hydroelectric projects in the northwest and directed Bonneville Power Administration to ''protect, mitigate, and enhance fish and wildlife to the extent affected by the development and operation of any hydroelectric project of the Columbia River and its tributaries...'' (4(h)(10)(A)). Under the Act, the Northwest Power Planning Council was created and recommendations for a comprehensive fish and wildlife program were solicited from the region's federal, state, and tribal fish and wildlife agencies. Among Montana's recommendations was the proposal that research be initiated to quantify acceptable seasonal minimum pool elevations to maintain or enhance the existing fisheries (Graham et al. 1982). Research to determine how operations of Libby Dam affect the reservoir and river fishery and to suggest ways to lessen these effects began in May, 1983. The framework for the Libby Reservoir Model (LRMOD) was completed in 1989. Development of Integrated Rule Curves (IRCs) for Libby Dam operation was completed in 1996 (Marotz et al. 1996). The Libby Reservoir Model and the IRCs continue to be refined (Marotz et al 1999). Initiation of mitigation projects such as lake rehabilitation and stream restoration began in 1996. The primary focus of the Libby Mitigation project now is to

  17. Atmospheric Rivers, Climate Change, and the Howard Hanson Dam

    Science.gov (United States)

    Warner, M.; Mass, C.; Shaffer, K.; Brettman, K.

    2017-12-01

    All wintertime extreme precipitation and major flooding events in Western Washington are associated with Atmospheric Rivers (ARs), narrow bands of elevated integrated water vapor transport (IVT) stretching from the tropical Pacific Ocean to the Pacific Northwest coast. Several studies over the last decade have suggested that climate change could impact the intensity, frequency, timing, and structure of Pacific Northwest extreme precipitation. The Howard Hanson Dam is situated on the Green River in the central Cascade Mountains in Western Washington and is operated by the US Army Corps of Engineers (USACE) in Seattle. The reservoir behind the dam has two functions: It is the main water supply for the city of Tacoma and is filled during the summer months, and it is empty during winter months when it is used for flood risk management during AR events, protecting billions of dollars of infrastructure downstream. The reservoir is maintained by the Cascade Mountains' abundant winter snowpack and precipitation. Since the reservoir behind Howard Hanson Dam must be empty before the flood season starts and is reliant on snowpack and precipitation to fill in late spring, impacts due to climate change are important for how the USACE operates and manages flood risk and water supply in the future. This work describes changes in the structure, climatology, and seasonality of cool-season atmospheric rivers influencing the west coast of North America by examining the projections of Coupled Model Intercomparison Project 5 (CMIP5) climate simulations forced by the Representative Concentration Pathway (RCP) 8.5 scenario. There are only slight changes in AR frequency and seasonality between historical (1970-1999) and future (2070-2099) periods considering the most extreme days (99th percentile) in integrated water vapor transport (IVT) along the West Coast, particularly along the southern part of the U.S. west coast, where some changes in the most extreme events are statistically

  18. Environmental considerations in energy planning for the Amazon region: Downstream effects of dams

    International Nuclear Information System (INIS)

    Manyari, Waleska Valenca; de Carvalho, Osmar Abilio

    2007-01-01

    The most salient current feature of the electric energy sector in Brazil is the pressing need for expansion. In this context, the hydroelectric resources of the Amazon region are considered a competitive alternative despite the structural problems they entail. These include reliance of new investments and environmental restrictions. Concerning the latter, plans to build large-scale dams in the region have drawn criticism mainly on account of the loss of forest cover in areas flooded by dam reservoirs and the conflicts concerning the relocation of indigenous and riverside communities in the region. This article seeks to contribute to better understanding of the environmental issue in the Amazon by focusing attention on the downstream effects of dams, which have large-scale, hitherto neglected ecological repercussions. The impact of dams extends well beyond the area surrounding the artificial lakes they create, harming rich Amazon wetland ecosystems. The morphology of dammed rivers changes in response to new inputs of energy and matter, which may in turn destroy certain biotopes. This is a remote-sensing-based case study of the Tucurui hydroelectric scheme in the Amazon state of Para. Attention is drawn to the need to take into account effects on alluvial rivers downstream from hydroelectric power plants when it comes to making planning decisions, as part of a sustainable energy policy

  19. Hungry Horse mitigation: Aquatic modeling of the selective withdrawal system -- Hungry Horse Dam, Montana

    International Nuclear Information System (INIS)

    Marotz, B.L.; Althen, C.; Gustafson, D.

    1994-04-01

    Hungry Horse Dam presently releases frigid water from the bottom of the reservoir all year long. Cold water effects insect production and fish growth downstream. Rapid temperature changes of up to 8.3 C (14 F) have been measured in the Flathead River downstream of the South Fork confluence, controlled by dam discharges. Thermal effects from Hungry Horse Dam are detectable for over 64 Km downstream to Flathead Lake. The installation of a selective withdrawal structure on each of the dam's discharge penstocks was determined to be the most cost-effective means to provide constant, permanent temperature control without impacting power production and flexibility in dam operation. The thermal model presented herein revealed that fish growth potential in the river would increase two to five times through selective withdrawal, temperature control. Temperature control is possible over the entire range of turbine discharge capacity, with very little effect on power production. Findings indicate that angling would improve through higher catch rates and larger fish. Temperature control will solve the most serious impact to river health. However, flow fluctuations will continue to effect insect production and usable fishery habitat in the Flathead River. A natural thermal regime combined with moderated flow fluctuation would further enhance riverine food production, trout growth and recreation potential

  20. Reconstructing Sediment Supply, Transport and Deposition Behind the Elwha River Dams

    Science.gov (United States)

    Beveridge, C.

    2017-12-01

    The Elwha River watershed in Olympic National Park of Washington State, USA is predominantly a steep, mountainous landscape where dominant geomorphic processes include landslides, debris flows and gullying. The river is characterized by substantial variability of channel morphology and fluvial processes, and alternates between narrow bedrock canyons and wider alluvial reaches for much of its length. Literature suggests that the Elwha watershed is topographically and tectonically in steady state. The removal of the two massive hydropower dams along the river in 2013 marked the largest dam removal in history. Over the century long lifespan of the dams, approximately 21 million cubic meters of sediment was impounded behind them. Long term erosion rates documented in this region and reservoir sedimentation data give unprecedented opportunities to test watershed sediment yield models and examine dominant processes that control sediment yield over human time scales. In this study, we aim to reconstruct sediment supply, transport and deposition behind the Glines Canyon Dam (most upstream dam) over its lifespan using a watershed modeling approach. We developed alternative models of varying complexity for sediment production and transport at the network scale driven by hydrologic forcing. We simulate sediment supply and transport in tributaries upstream of the dam. The modeled sediment supply and transport dynamics are based on calibrated formulae (e.g., bedload transport is simulated using Wilcock-Crowe 2003 with modification based on observed bedload transport in the Elwha River). Observational data that aid in our approach include DEM, channel morphology, meteorology, and streamflow and sediment (bedload and suspended load) discharge. We aim to demonstrate how the observed sediment yield behind the dams was influenced by upstream transport supply and capacity limitations, thereby demonstrating the scale effects of flow and sediment transport processes in the Elwha River

  1. Hydrological impact of high-density small dams in a humid catchment, Southeast China

    Science.gov (United States)

    Lu, W.; Lei, H.; Yang, D.

    2017-12-01

    The Jiulong River basin is a humid catchment with a drainage area of 14,741 km2; however, it has over 1000 hydropower stations within it. Such catchment with high-density small dams is scarce in China. Yet few is known about the impact of high-density small dams on streamflow changes. To what extent the large number of dams alters the hydrologic patterns is a fundamental scientific issue for water resources management, flood control, and aquatic ecological environment protection. Firstly, trend and change point analyses are applied to determine the characteristics of inter-annual streamflow. Based on the detected change point, the study period is divided into two study periods, the ``natural'' and ``disturbed'' periods. Then, a geomorphology-based hydrological model (GBHM) and the fixing-changing method are adopted to evaluate the relative contributions of climate variations and damming to the changes in streamflow at each temporal scale (i.e., from daily, monthly to annual). Based on the simulated natural streamflow, the impact of dam construction on hydrologic alteration and aquatic ecological environment will be evaluated. The hydrologic signatures that will be investigated include flood peak, seasonality of streamflow, and the inter-annual variability of streamflow. In particular, the impacts of damming on aquatic ecological environment will be investigated using eco-flow metrics and indicators of hydrologic alteration (IHA) which contains 33 individual streamflow statistics that are closely related to aquatic ecosystem. The results of this study expect to provide a reference for reservoir operation considering both ecological and economic benefits of such operations in the catchment with high-density dams.

  2. Boundary element analysis of earthquake induced hydrodynamic pressures in a water reservoir

    International Nuclear Information System (INIS)

    Jablonski, A.M.

    1988-11-01

    The seismic analysis of concrete gravity and arch dams is affected by the hydrodynamic pressures in the water reservoir. Boundary element method (BEM) formulations are derived for the hydrodynamic pressures arising in a gravity dam-reservoir-foundation system, treating both 2- and 3-dimensional cases. The formulations are based on the respective mathematical models which are governed by two- and three-dimensional Helmholtz equations with appropriate boundary conditions. For infinite reservoirs, loss of energy due to pressure waves moving away toward infinity strongly influence response. Since it is not possible to discretize an infinite extent, the radiation damping due to outgoing waves is accounted for by incorporating special boundary conditions at the far end, and in a similar manner the loss of energy due to absorption of waves by a flexible bottom of reservoir and banks can be accounted for by a special condition along the boundaries. Numerical results are obtained and compared with available classical solutions and convergence of numerical results with the size and number of boundary elements is studied. It is concluded that the direct boundary element method is an effective tool for the evaluation of the hydrodynamic pressures in finite and infinite dam-reservoir-foundation systems subjected to harmonic-type motion, and can easily be extended to any type of random motion with fast Fourier transform techniques. 82 refs., 65 figs., 25 tabs

  3. Small reservoir effects on headwater water quality in the rural-urban fringe, Georgia Piedmont, USA

    Directory of Open Access Journals (Sweden)

    Dr.. Amber R. Ignatius, Geographer

    2016-12-01

    Full Text Available Small reservoirs are prevalent landscape features that affect the physical, chemical, and biological characteristics of headwater streams. Tens of thousands of small reservoirs, often less than a hectare in size, were constructed over the past century within the United States. While remote-sensing and geographic-mapping technologies assist in identifying and quantifying these features, their localized influence on water quality is uncertain. We report a year-long physicochemical study of nine small reservoirs (0.15–2.17 ha within the Oconee and Broad River Watersheds in the Georgia Piedmont. Study sites were selected along an urban-rural gradient with differing amounts of agricultural, forested, and developed land covers. Sites were sampled monthly for discharge and inflow/outflow water quality parameters (temperature, specific conductance, pH, dissolved oxygen, turbidity, alkalinity, total phosphorus, total nitrogen, nitrate, ammonium. While the proportion of developed land cover within watersheds had positive correlations with reservoir specific conductivity values, agricultural and forested land covers showed correlations (positive and negative, respectively with reservoir alkalinity, total nitrogen, nitrate, and specific conductivity. The majority of outflow temperatures were warmer than inflows for all land uses throughout the year, especially in the summer. Outflows had lower nitrate concentrations, but higher ammonium. The type of outflow structure was also influential; top-release dams showed higher dissolved oxygen and pH than bottom-release dams. Water quality effects were still evident 250 m below the dam, albeit reduced.

  4. Influence of Extreme Strength in Water Quality of the Jucazinho Reservoir, Northeastern Brazil, PE

    Directory of Open Access Journals (Sweden)

    Rafael Roney Camara de Melo

    2017-12-01

    Full Text Available The Jucazinho reservoir was built in the State of Pernambuco, Northeastern Brazil, to water supply in a great part of the population that live in the semi-arid of Pernambuco. This reservoir controls the high part of Capibaribe river basin, area affected several actions that can compromise the reservoir water quality such as disposal of domestic sewage, industrial wastewater and agriculture with use of fertilizers. This study aimed to identify the factors that lead to water quality of the Jucazinho reservoir using a database containing information of nine years of reservoir water quality monitoring in line with a multivariate statistical technique known as Principal Component Analysis (PCA. To use this technique, it was selected two components which determine the quality of the reservoir water. The first principal component, ranging from an annual basis, explained the relationship between the development of cyanobacteria, the concentration of dissolved solids and electrical conductivity, comparing it with the variation in the dam volume, total phosphorus levels and turbidity. The second principal component, ranging from a mensal basis, explained the photosynthetic activity performed by cyanobacteria confronting with the variation in the dam volume. It observed the relationship between water quality parameters with rainfall, featuring an annual and seasonal pattern that can be used as reference to behaviour studies of this reservoir.

  5. Quantification of Interbasin Transfers into the Addicks Reservoir during Hurricane Harvey

    Science.gov (United States)

    Sebastian, A.; Juan, A.; Gori, A.; Maulsby, F.; Bedient, P. B.

    2017-12-01

    Between August 25 and 30, Hurricane Harvey dropped unprecedented rainfall over southeast Texas causing widespread flooding in the City of Houston. Water levels in the Addicks and Barker reservoirs, built in the 1940s to protect downtown Houston, exceeded previous records by approximately 2 meters. Concerns regarding structural integrity of the dams and damage to neighbourhoods in within the reservoir pool resulted in controlled releases into Buffalo Bayou, flooding an estimated 4,000 additional structures downstream of the dams. In 2016, during the Tax Day it became apparent that overflows from Cypress Creek in northern Harris County substantially contribute to water levels in Addicks. Prior to this event, little was known about the hydrodynamics of this overflow area or about the additional stress placed on Addicks and Barker reservoirs due to the volume of overflow. However, this information is critical for determining flood risk in Addicks Watershed, and ultimately Buffalo Bayou. In this study, we utilize the recently developed HEC-RAS 2D model the interbasin transfer that occurs between Cypress Creek Watershed and Addicks Reservoir to quantify the volume and rate at which water from Cypress enters the reservoir during extreme events. Ultimately, the results of this study will help inform the official hydrologic models used by HCFCD to determine reservoir operation during future storm events and better inform residents living in or above the reservoir pool about their potential flood risk.

  6. Three Sisters Dam modifications and performance

    Energy Technology Data Exchange (ETDEWEB)

    Courage, L.J.R. [Monenco AGRA Inc., Calgary, AB (Canada)

    1995-12-31

    Recent modifications and maintenance carried out at the Three Sisters Dam, in the Alberta Rockies south of the town of Canmore, were described. A detailed account was given of the dam`s geological setting, its abnormally high leakage through the foundation and its sinkhole activity. Results of studies aimed at finding the cause of leakage and sinkhole occurrences were reviewed. Modifications made to the dam since 1951 were detailed, as were modifications to handle probable maximum flood levels. Three approaches for estimating failure probabilities after identification of failure modes were described. The overall conclusion was that based on constant leakage, no settlement in the dam, penstocks, or the powerhouse since construction, the Three Sisters Dam was stable. 1 ref.

  7. Exporting dams: China's hydropower industry goes global.

    Science.gov (United States)

    McDonald, Kristen; Bosshard, Peter; Brewer, Nicole

    2009-07-01

    In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas.

  8. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    Science.gov (United States)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  9. Surface water leakage, sedimentation and evaporation in arid regions: A case study of the Gargar dam, Algeria

    Directory of Open Access Journals (Sweden)

    Hassen Benfetta

    2017-12-01

    Full Text Available This study was carried out in order to assess the total capacity loss in Gargar dam, third-largest in Algeria, due to the mudding of the reservoir, intense evaporation and water leaks. We analysed the variation in leakage as a function of the reservoir level, and quantify losses due to leaks, sedimentation and evaporation. We relied on site visits and data obtained from the Algerian Agency for Dams and Transfers to assess the leakage volume; reservoir level; sedimentation and evaporation levels for the period 1988–2015. We present an updated report of this problem through the dam. We estimated total average losses of 23 million m3·year−1 for the period 1988–2015, made up of leakage (0.3 million m3·year−1, evaporation (18 million m3·year−1 and dead storage for 4.6 million m3·year−1. However, total losses for 2004 were estimated at 113.9 million m3, which increased to the alarming value of 166.8 million m3 in 2015. We suggest improving the waterproofness by a concrete screen, and reducing mudding and evaporation by reforestation, to increase the storage capacity of the dam.

  10. EUTROPHICATION OF WATER RESERVOIRS AND ROLE OF MACROPHYTES IN THIS PROCESS

    Directory of Open Access Journals (Sweden)

    Joanna Jadwiga Sender

    2017-06-01

    Full Text Available The paper presents the problem related with the process of eutrophication, with special emphasis on dam reservoirs. Eutrophication is a global process, threatening the water ecosystem on every continent. It often leads to their degradation. Particularly vulnerable to eutrophication are artificial reservoirs which are dam reservoirs. This paper describes the mechanisms of eutrophication. We also pointed to the importance of aquatic plants in the process of water purification, as well as the possibility of multilateral use. Recently, in the world and in Poland there is a tendency to pay attention to the natural or semi-natural method of water purification (including constructed wetland. On the one hand, the presence of macrophytes in water bodies is a guarantor of good ecological status, on the other hand, the undeniable aesthetic value.

  11. Long-Term Downstream Effects of a Dam on a Lowland River Flow Regime: Case Study of the Upper Narew

    Directory of Open Access Journals (Sweden)

    Paweł Marcinkowski

    2017-10-01

    Full Text Available Most European riverine ecosystems suffer from the negative influence of impoundments on flow regime. Downstream effects of dams lead to a number of environmental and socioeconomic risks and, therefore, should be thoroughly examined in specific contexts. Our study aims to quantify the downstream effects of the Siemianówka Reservoir (Upper Narew, Poland, using statistical analysis of key elements of the river’s flow regime, such as the flow duration and recurrence of floods and droughts. In a comparative study on control catchments not influenced by impoundments (the Supraśl and Narewka Rivers, we revealed the following downstream effects of the analyzed dam: significant shortening of spring floods, reduction of the duration and depth of summer droughts, decrease of the maximum discharge, and homogenization of the discharge hydrographs. Although we determined a significant decrease in the duration of summer floods in the “before” and “after” dam function periods, we showed that this issue is regional, climate-related, and replicated in control catchments, rather than an evident downstream effect of the dam. We conclude that significant hydrological downstream effects of the Siemianówka dam–reservoir system could have been the main driver inducing the deterioration of the anastomosing stretch of the Narew River downstream of the dam.

  12. Monitoring the ongoing deformation and seasonal behaviour affecting Mosul Dam through space-borne SAR data

    Science.gov (United States)

    Tessari, G.; Riccardi, P.; Pasquali, P.

    2017-12-01

    Monitoring of dam structural health is an important practice to control the structure itself and the water reservoir, to guarantee efficient operation and safety of surrounding areas. Ensuring the longevity of the structure requires the timely detection of any behaviour that could deteriorate the dam and potentially result in its shutdown or failure.The detection and monitoring of surface displacements is increasingly performed through the analysis of satellite Synthetic Aperture Radar (SAR) data, thanks to the non-invasiveness of their acquisition, the possibility to cover large areas in a short time and the new space missions equipped with high spatial resolution sensors. The availability of SAR satellite acquisitions from the early 1990s enables to reconstruct the historical evolution of dam behaviour, defining its key parameters, possibly from its construction to the present. Furthermore, the progress on SAR Interferometry (InSAR) techniques through the development of Differential InSAR (DInSAR) and Advanced stacking techniques (A-DInSAR) allows to obtain accurate velocity maps and displacement time-series.The importance of these techniques emerges when environmental or logistic conditions do not allow to monitor dams applying the traditional geodetic techniques. In such cases, A-DInSAR constitutes a reliable diagnostic tool of dam structural health to avoid any extraordinary failure that may lead to loss of lives.In this contest, an emblematic case will be analysed as test case: the Mosul Dam, the largest Iraqi dam, where monitoring and maintaining are impeded for political controversy, causing possible risks for the population security. In fact, it is considered one of the most dangerous dams in the world because of the erosion of the gypsum rock at the basement and the difficult interventions due to security problems. The dam consists of 113 m tall and 3.4 km long earth-fill embankment-type, with a clay core, and it was completed in 1984.The deformation

  13. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  14. Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA

    Science.gov (United States)

    Merritts, Dorothy; Walter, Robert; Rahnis, Michael; Hartranft, Jeff; Cox, Scott; Gellis, Allen; Potter, Noel; Hilgartner, William; Langland, Michael; Manion, Lauren; Lippincott, Caitlin; Siddiqui, Sauleh; Rehman, Zain; Scheid, Chris; Kratz, Laura; Shilling, Andrea; Jenschke, Matthew; Datin, Katherine; Cranmer, Elizabeth; Reed, Austin; Matuszewski, Derek; Voli, Mark; Ohlson, Erik; Neugebauer, Ali; Ahamed, Aakash; Neal, Conor; Winter, Allison; Becker, Steven

    2011-01-01

    Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2-5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.

  15. Flood effects provide evidence of an alternate stable state from dam management on the Upper Missouri River

    Science.gov (United States)

    Skalak, Katherine; Benthem, Adam J.; Hupp, Cliff R.; Schenk, Edward R.; Galloway, Joel M.; Nustad, Rochelle A.

    2017-01-01

    We examine how historic flooding in 2011 affected the geomorphic adjustments created by dam regulation along the approximately 120 km free flowing reach of the Upper Missouri River bounded upstream by the Garrison Dam (1953) and downstream by Lake Oahe Reservoir (1959) near the City of Bismarck, ND, USA. The largest flood since dam regulation occurred in 2011. Flood releases from the Garrison Dam began in May 2011 and lasted until October, peaking with a flow of more than 4200 m3 s−1. Channel cross-section data and aerial imagery before and after the flood were compared with historic rates of channel change to assess the relative impact of the flood on the river morphology. Results indicate that the 2011 flood maintained trends in island area with the loss of islands in the reach just below the dam and an increase in island area downstream. Channel capacity changes varied along the Garrison Segment as a result of the flood. The thalweg, which has been stable since the mid-1970s, did not migrate. And channel morphology, as defined by a newly developed shoaling metric, which quantifies the degree of channel braiding, indicates significant longitudinal variability in response to the flood. These results show that the 2011 flood exacerbates some geomorphic trends caused by the dam while reversing others. We conclude that the presence of dams has created an alternate geomorphic and related ecological stable state, which does not revert towards pre-dam conditions in response to the flood of record. This suggests that management of sediment transport dynamics as well as flow modification is necessary to restore the Garrison Segment of the Upper Missouri River towards pre-dam conditions and help create or maintain habitat for endangered species. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  16. Mitigation for the Construction and Operation of Libby Dam, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Greg; Marotz, Brian L.; Dunnigan, James (Montana Department of Fish, Wildlife and Parks, Libby, MT)

    2002-09-01

    ''Mitigation for the Construction and Operation of Libby Dam'' is part of the Northwest Power Planning Council's resident fish and wildlife program. The program was mandated by the Northwest Planning Act of 1980, and is responsible for mitigating for damages to fish and wildlife caused by hydroelectric development in the Columbia River Basin. The objective of Phase I of the project (1983 through 1987) was to maintain or enhance the Libby Reservoir fishery by quantifying seasonal water levels and developing ecologically sound operational guidelines. The objective of Phase II of the project (1988 through 1996) was to determine the biological effects of reservoir operations combined with biotic changes associated with an aging reservoir. The objectives of Phase III of the project (1996 through present) are to implement habitat enhancement measures to mitigate for dam effects, to provide data for implementation of operational strategies that benefit resident fish, monitor reservoir and river conditions, and monitor mitigation projects for effectiveness.

  17. Dam safety management in Victoria (Australia)

    International Nuclear Information System (INIS)

    Adem, J.

    1996-01-01

    The Victoria state government's decision to make dam owners accountable for safety and upkeep of their dams was reported. To give effect to this decision a series of guidelines have been developed which outline the required activities and skills to ensure that dams are properly managed within a framework of 'light-handed' regulation. The guidelines are also intended to ensure that dam management becomes an integral part of the business decision making process, not just a set of prescribed technical procedures. Details of the direction being taken and the proposed controls to ensure compliance with national and international standards were described. 4 refs., 2 figs

  18. Numerical modelling for stability of tailings dams

    OpenAIRE

    Auchar, Muhammad; Mattsson, Hans; Knutsson, Sven

    2013-01-01

    A tailings dam is a large embankment structure that is constructed to store the waste from the mining industry. Stability problems may occur in a tailings dam due to factors such as quick rate of raising, internal erosion and liquefaction. The failure of a tailings dam may cause loss of human life and environmental degradation. Tailings Dams must not only be stable during the time the tailings storage facility is in operation, but also long time after the mine is closed. In Sweden, the licens...

  19. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    Anvendelse af optimeringsteknik til drift af reservoirer er blevet et væsentligt element i vandressource-planlægning og -forvaltning. Traditionelt har reservoirer været styret af heuristiske procedurer for udtag af vand, suppleret i en vis udstrækning af subjektive beslutninger. Udnyttelse af...... reservoirer involverer en lang række interessenter med meget forskellige formål (f.eks. kunstig vanding, vandkraft, vandforsyning mv.), og optimeringsteknik kan langt bedre lede frem til afbalancerede løsninger af de ofte modstridende interesser. Afhandlingen foreslår en række tiltag, hvormed traditionelle...

  20. Circuitous to single thread: post-dam geomorphic transformation of the Colorado River in its delta

    Science.gov (United States)

    Mueller, E. R.; Schmidt, J. C.

    2017-12-01

    The Colorado River in its delta has transformed from a maze of secondary and distributary channels to an intermittent or ephemeral stream largely disconnected from formerly active channels and floodplains. Periodic post-dam floods have demonstrated that channel migration and shifting during floods increased the extent and diversity of riparian vegetation, and suggested that restoration of fluvial processes that promote re-activation of these former channels may enhance ecosystem rehabilitation. But restoration efforts in the delta are complicated by the fact that the Colorado River has the largest reservoir size in relation to its mean annual flow of any large river in North America and most of its sediment supply is completely blocked in upstream reservoirs. As a result, small controlled floods intended to inundate formerly active channels and rejuvenate riparian vegetation must consider the new relationship between stream flow and the delta's transformed geomorphology. Post-dam channel change has been dominated by the abandonment of secondary and distributary channels, with 3 to 4 meters of bed incision in the upstream part of the delta that diminishes downstream. Initial bed incision of 2 to 3 meters occurred rapidly following completion of Hoover Dam in 1936, before further upstream water development reduced delta flows to near zero by the mid-1960s. The largest post-dam floods occurred in the 1980s, which resulted in 10s to 100s of meters of lateral migration, channel switching, and the reactivation of secondary channels and floodplains rarely inundated since dam completion. Smaller flow pulses in the 1990s and 2000s further incised the thalweg to its minimum elevation, resulting in a narrow single-thread channel inset within the multi-channel surface active during the 1980s. In 2014, an experimental pulse flow was released to the river channel with a peak discharge approximately 5% of the typical pre-dam flood peak. Topographic change was confined to the main

  1. The fate of copepod populations in the Paranapanema River (São Paulo, Brazil, downstream from the Jurumirim dam

    Directory of Open Access Journals (Sweden)

    Mitsuka Patricia Maria

    2002-01-01

    Full Text Available The longitudinal changes in the structure of copepod populations were examined during the dry and rainy seasons in a 42 km stretch of the Paranapanema River downstream from the dam of the Jurumirim Reservoir. Samples were taken in the "lacustrine" zone of the reservoir near the dam, and also at 12 stations distributed in the middle and the lateral regions of the channel of the Paranapanema River downstream from the dam. The following species of Cyclopoida were found at the sites: Thermocyclops decipiens, Thermocyclops minutus, Paracyclops sp., Tropocyclops sp and Mesocyclops sp., and of Calanoida: Argyrodiaptomus furcatus, Notodiaptomus iheringi and Notodiaptomus conifer. In the reservoir sampling station, the copepod abundance during the dry and rainy seasons corresponded to 41 and 51% of the total zooplankton, respectively. This difference could be related to the rainfall and water level variations, and especially to the influence of variables such as water temperature, dissolved oxygen and chlorophyll-a contents. No significant differences in organism numbers were recorded among samples of zooplankton taken in the middle and near-bank parts of the river. In relation to longitudinal variation in the Paranapanema River stretch, a significant decrease in density and disappearance of some species were recorded 11km downstream of the dam during the dry season. At the stations 32km from the dam, a drastic reduction in copepod abundance was observed in the rainy season. These observations could be linked not only to environmental changes from lentic to lotic conditions, but also to the combination of certain factors such as current velocity, water outflow of the reservoir, and rainfall.

  2. Spatial variation of sediment mineralization supports differential CO2 emissions from a tropical hydroelectric reservoir

    Directory of Open Access Journals (Sweden)

    Simone Jaqueline Cardoso

    2013-04-01

    Full Text Available Substantial amounts of organic matter (OM from terrestrial ecosystems are buried as sediments in inland waters. It is still unclear to what extent this OM constitutes a sink of carbon, and how much of it is returned to the atmosphere upon mineralization to carbon dioxide (CO2. The construction of reservoirs affects the carbon cycle by increasing OM sedimentation at the regional scale. In this study we determine the OM mineralization in the sediment of three zones (river, transition and dam of a tropical hydroelectric reservoir in Brazil as well as identify the composition of the carbon pool available for mineralization. We measured sediment OC mineralization rates and related them to the composition of the OM, bacterial abundance and pCO2 of the surface water of the reservoir. Terrestrial OM was an important substrate for the mineralization. In the river and transition zones most of the OM was allochthonous (56 % and 48 %, respectively while the dam zone had the lowest allochthonous contribution (7 %. The highest mineralization rates were found in the transition zone (154.80 ± 33.50 mg C m-2 d-1 and the lowest in the dam (51.60 ± 26.80 mg C m-2 d-1. Moreover, mineralization rates were significantly related to bacterial abundance (r2 = 0.50, p < 0.001 and pCO2 in the surface water of the reservoir (r2 = 0.73, p < 0.001. The results indicate that allochthonous OM has different contributions to sediment mineralization in the three zones of the reservoir. Further, the sediment mineralization, mediated by heterotrophic bacteria metabolism, significantly contributes to CO2 supersaturation in the water column, resulting in higher pCO2 in the river and transition zones in comparison with the dam zone, affecting greenhouse gas emission estimations from hydroelectric reservoirs.

  3. Spatiotemporal Variations of Extreme Precipitation under a Changing Climate in the Three Gorges Reservoir Area (TGRA

    Directory of Open Access Journals (Sweden)

    Mingquan Lü

    2018-01-01

    Full Text Available The Three Gorges Dam (TGD is one of the largest hydroelectric projects in the world. Monitoring the spatiotemporal distribution of extreme precipitation offers valuable information for adaptation and mitigation strategies and reservoir management schemes. This study examined variations in extreme precipitation over the Three Gorges Reservoir area (TGRA in China to investigate the potential role of climate warming and Three Gorges Reservoir (TGR. The trends in extreme precipitation over the TGRA were investigated using the iterative-based Mann–Kendall (MK test and Sen’s slope estimator, based on weather station daily data series and TRMM (Tropical Rainfall Measuring Mission data series. The mean and density distribution of extreme precipitation indices between pre-dam and post-dam, pre-1985 and post-1985, and near and distant reservoir area were assessed by the Mann–Whitney test and the Kolmogorov–Smirnov test. The ratio of extreme precipitation to non-extreme precipitation became larger. The precipitation was characterized by increases in heavy precipitation as well as decreases in light and moderate rain. Comparing extreme precipitation indices between pre-1985 (cooling and post-1985 (warming indicated extreme precipitation has changed to become heavier. Under climate warming, the precipitation amount corresponding to more than the 95th percentile increased at the rate of 6.48%/°C. Results from comparing extreme precipitation for the pre- and post-dam, near reservoir area (NRA and away from the reservoir area (ARA imply an insignificant role of the TGR on rainfall extremes over the TGRA. Moreover, the impoundment of TGR did not exert detectable impacts on the surface relative humidity (RH and water vapor pressure (WP.

  4. Evaluation of reservoir operation strategies for irrigation in the Macul Basin, Ecuador

    Directory of Open Access Journals (Sweden)

    Vicente Tinoco

    2016-03-01

    Full Text Available Study focus: An irrigation project is planned in the study basin for developing the agriculture as the main income in the region. The proposed water system comprises three large reservoirs damming the rivers Macul and Maculillo. The river basin planning and operation were investigated by modelling alternative reservoir operation strategies aiming at a sustainable balance between irrigation and river ecology by integrated reservoir/river management. New hydrological insights for the region: After simulation of long-term meteorological series in a model of the integrated water system, covering several historical extreme events, results indicate that the planned irrigation volumes are higher than the available water for a sustainable irrigation strategy. Two lines of action are suggested for reaching the target irrigation demands: design of a deficit irrigation system, and modifications to the reservoir's spillway height. Keywords: Reservoir operation, Conceptual model, Irrigation

  5. Fish ladder of Lajeado Dam: migrations on one-way routes?

    Directory of Open Access Journals (Sweden)

    Angelo Antônio Agostinho

    Full Text Available Fish ladders are generally conceived to reestablish connectivity among critical habitats for migratory species, thus mitigating the impacts of the blockage of migration routes by dams. If this management tool is to be meaningful for conserving fish species, it must provide a fully permeable connection and assure both upward and downward movements. However, because reservoirs have very different hydrodynamics than the original river, it is expected that, at least in the inner area, they may constitute an additional barrier to this movement, especially for descending fish. Thus, the present study sought to determine if migratory fish and their offspring disperse downstream from the dam after ascending a ladder and spawning in the upper reaches of a basin. To achieve this purpose, we evaluated the limitation imposed by lentic areas to the descent of eggs, larvae and adults of migratory species; we also determined the abundance and composition of larvae present in the plankton near the dam, and compared the intensity of the upward and downward movements of adult fish. Samples of ichthyoplankton were taken upriver, inside the reservoir, in the river downstream from the dam, and in the forebay of the Lajeado Dam on the Tocantins River (Luis Eduardo Magalhães Hydroelectric Plant, from October, 1999 through September, 2004. The densities of fish ascending and descending the ladder were determined experimentally on eight occasions, from June, 2004 to March, 2005. Due to difficulties in identifying the true fish origin (up or down in the environments connected by the fish passage system, the evaluation of the distribution of migratory fish in reservoirs was based on the landings of the commercial fishery conducted along the Itaipu Reservoir during the four years preceding (2001 through 2003 the construction of the lateral channel (fish-passage mechanism. Fish eggs and larvae drifting down the Tocantins River did not appear in samples taken in the lower

  6. Olympic Dam - the first decade

    International Nuclear Information System (INIS)

    Newton, A.W.; Wilson, M.A.; Harris, J.

    1988-01-01

    Most aspects of the pre-production phase of the Olympic Dam Project, from commencement of exploration in May 1975 through to commitment to development in December 1985 are documented here. The discovery by Western Mining Corporation Ltd of copper mineralisation on Roxby Downs Station in July 1975 has led to one of the more intensive base-metal exploration programmes undertaken in Australia. Comprehensive exploration, evaluation and feasibility studies between 1975 and 1985 have delineated a probable 450 million tonnes of higher grade ore containing 2.5% copper, 0.8 kg/t uranium oxide, 0.6 g/t gold and 6.0 g/t silver. The total resource is estimated at 2 billion tonnes containing 1.6% copper, 0.6 kg/t uranium oxide, 0.6 g/t gold and 3.5 g/t silver. At 31 December 1985, over 540 km of surface and underground drilling had been completed, comprising over 700 surface drillholes totalling 234 km of core and 218 km of open-hole drilling, and about 900 underground diamond-drillholes totalling 90 km. The Whenan Shaft had been sunk to 500 m and driving on three levels totalled almost 10 km. More than one million tonnes of ore and mullock were raised during development. A pilot treatment plant commissioned on site produced concentrates, matte and blister copper, and ammonium diuranate. Following a technical study of the Olympic Dam Project, completed in March 1985, and a subsequent economic feasibility study, it was announced on 11 June 1985 that the initial project was considered to be commercially viable. On 8 December 1985, the joint venturers, Western Mining Corporation Holdings Ltd (51%) and the BP Group (49%), announced their commitment to the Project. An appendix lists the important events that occurred between January 1986 and December 1987 in bringing Olympic Dam to the production state. 26 refs., 17 figs., 5 tabs., ills

  7. Assessment of hydrological changes in the Nile River due to the construction of Renaissance Dam in Ethiopia

    Directory of Open Access Journals (Sweden)

    Mohammed El Bastawesy

    2015-06-01

    Full Text Available This paper assesses impact of the Renaissance Dam on Ethiopia; on the Nile discharge ultimately reaches Egypt downstream. The Landsat-8 satellite images of 2013 were obtained and interpreted to identify locations for the construction sites for the Renaissance Dam. Then the Shuttle Radar Topography Mission (SRTM data were obtained and processed to create a digital elevation model (DEM for the Blue Nile upstream areas that will be submerged. Different scenarios for the dams’ heights and resulting storages were simulated to estimate the resulting abstraction of the Blue Nile flows until completion of the project and the annual losses due to evaporation thereafter. The current site (506 m asl for the Renaissance Dam allows the creation of a 100 m deep reservoir with a total storage of 17.5 km3; overflows will occur at that lake’s level (606 m asl from the north western part of the developed lake into Rosaires downstream. Construction of the spillway dam to control the overflow area can allow the creation of a 180 m deep lake that store up to 173 km3 in a lake that will cover 3130 km2. The analysis of Tropical Rainfall Monitoring Mission (TRMM suggests that the variation of total annual rainfall could reach 20%, thus the resulting hydrological fluctuations could affect the estimated filling time, the operational functions and discharge downstream. The negative hydrological impacts of the Renaissance Dam will increase by increasing the height of its spillway dam, as increasing the storage capacity could affect the strategic storage for the reservoirs in Egypt and Sudan. It is strongly recommended that an agreement should be reached to compromise the storage capacities and water supplies for all dams on the Nile to thoroughly satisfy the necessary needs.

  8. Advancing reservoir operation description in physically based hydrological models

    Science.gov (United States)

    Anghileri, Daniela; Giudici, Federico; Castelletti, Andrea; Burlando, Paolo

    2016-04-01

    Last decades have seen significant advances in our capacity of characterizing and reproducing hydrological processes within physically based models. Yet, when the human component is considered (e.g. reservoirs, water distribution systems), the associated decisions are generally modeled with very simplistic rules, which might underperform in reproducing the actual operators' behaviour on a daily or sub-daily basis. For example, reservoir operations are usually described by a target-level rule curve, which represents the level that the reservoir should track during normal operating conditions. The associated release decision is determined by the current state of the reservoir relative to the rule curve. This modeling approach can reasonably reproduce the seasonal water volume shift due to reservoir operation. Still, it cannot capture more complex decision making processes in response, e.g., to the fluctuations of energy prices and demands, the temporal unavailability of power plants or varying amount of snow accumulated in the basin. In this work, we link a physically explicit hydrological model with detailed hydropower behavioural models describing the decision making process by the dam operator. In particular, we consider two categories of behavioural models: explicit or rule-based behavioural models, where reservoir operating rules are empirically inferred from observational data, and implicit or optimization based behavioural models, where, following a normative economic approach, the decision maker is represented as a rational agent maximising a utility function. We compare these two alternate modelling approaches on the real-world water system of Lake Como catchment in the Italian Alps. The water system is characterized by the presence of 18 artificial hydropower reservoirs generating almost 13% of the Italian hydropower production. Results show to which extent the hydrological regime in the catchment is affected by different behavioural models and reservoir

  9. Downstream impacts of dams: shifts in benthic invertivorous fish assemblages

    Science.gov (United States)

    Granzotti, Rafaela Vendrametto; Miranda, Leandro E.; Agostinho, Angelo A.; Gomes, Luiz Carlos

    2018-01-01

    Impoundments alter connectivity, sediment transport and water discharge in rivers and floodplains, affecting recruitment, habitat and resource availability for fish including benthic invertivorous fish, which represent an important link between primary producers and higher trophic levels in tropical aquatic ecosystems. We investigated long-term changes to water regime, water quality, and invertivorous fish assemblages pre and post impoundment in three rivers downstream of Porto Primavera Reservoir in south Brazil: Paraná, Baía and Ivinhema rivers. Impacts were distinct in the Paraná River, which is fully obstructed by the dam, less evident in the Baía River which is partially obstructed by the dam, but absent