The Richard B. Russell Dam on the Savannah River was built in 1984 by the US Army Corps of Engineers for power generation, flood control and recreation. The hydroelectric power station has 4 conventional units and 4 pump turbine units. The pump turbine units act like conventional units during power generation. However, when electricity demand is low, pump turbines are able to reverse and pump water back upstream to make more water available for the next period of peak demand.
Following concern about fish becoming entrained during pump operation, the Corps was required to assess and minimize its impact on the fish populations (predominantly threadfin and gizzard shad, blueback herring). As part of this effort, we installed a BioSonics DTX hydroacoustic system with one transducer in the intake bay of each of the 4 pump-back units.
The data collected with this fixed hydroacoustic system is processed with fish tracking algorithms or, when the fish density is too high to track, echo integrated. Either method provides information on fish entrainment over time and depth, among intakes and whether the rate of entrainment changes with the number of units operating.
Three key elements made this project feasible: (i) automated operation, which starts and stops data collection automatically during pump operation, (ii) the ability to slow multiplex among the 4 transducers and (iii) remote control and data access via satellite internet link.
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In addition to the fixed hydroacoustic system monitoring fish entrainment in the intake bays, mobile surveys are conducted monthly to estimate the total fish population and distribution in the tailwater area and periodically in the upstream and downstream reservoirs. We use GIS techniques to relate the hydroacoustic data to net catch and water quality information and to analyze and map the geographic distribution, as well as the vertical distribution in the water column. The mobile survey data also allowed us to delineate areas suitable for the installation of an aeration system. (See Miscellaneous for echograms and 3D images showing the reservoir bottom still covered in standing trees.)
Reference
Nestler, John J. M. et al. 1997. Richard B. Russell Phase III Completion Report: Impacts of Four-Unit Pumpback Operation. Technical Report EL-97-00, U.S. Army Engineers Waterways Experiment Station, Vicksburg, MS.