As part of its Civil Works mission, the U.S. Army Corps of Engineers (USACE) operates 75 hydropower facilities, which produce about one quarter of the nation’s hydroelectric power. Because of recent listings of salmon and steelhead under the Endangered Species Act, the USACE has undertaken numerous studies on the impacts of hydropower facilities on migratory fish. Battelle has assisted the Portland and Walla Walla Districts of the USACE with studies at Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary, John Day, The Dalles, and Bonneville Dams.

To mitigate impacts on juveniles migrating downstream, the USACE has developed and installed equipment at its facilities to guide fish away from turbine intakes. Examples of such guidance systems are surface bypass and collection structures (SBC), submersible screens, and behavioral guidance structures. To determine the effectiveness of these structures, Battelle conducts hydroacoustic evaluations of fish passage. Battelle has also developed multidimensional fluid dynamics models of all reaches within the federal hydropower system, as well as three-dimensional models of the Bonneville Dam. These models are used to assess the potential benefits of dam structural and operational changes to migratory fish.

Lower Granite Dam, Snake River – Battelle evaluated the performance of a prototype SBC that guides fish in the upper water column (where juvenile salmon typically migrate) to a surface exit. Fixed-location hydroacoustic technologies were used to assess the performance of the SBC, describe fish passage, and document the efficiency of submersible screens. Battelle also analyzed data on river conditions, dam operations, water currents, species composition, and run timing to provide a basis for interpreting the results of the biological studies.

Bonneville Dam, Columbia River – In conjunction with the USACE Waterways Experiment Station (WES), Battelle performed fixed-location hydroacoustic studies to assess fish passage and behavior near a prototype surface collector. The study was used to evaluate uncertainties associated with surface bypass technologies, such as the optimum combination of entrance dimensions, velocity, and flow to attract and safely pass juvenile salmonids. Battelle also initiated a study with WES and the Biological Research Division of the U.S. Geological Survey to observe the three-dimensional behavior of juvenile salmonids at high spatial and temporal resolution. The study will be used to establish behavioral criteria for identifying fish rejection of surface flow bypass entrances.

McNary Dam, Snake River – Battelle is continuing a study to observe the behavior of juvenile salmonids as they move through a turbine intake. High power, ultrasonic transmitters are inserted into the stomachs of fish to allow tracking during turbine intake passage. Results will be used to assess the population-level benefits of potential turbine modifications.

Battelle’s work with fish passage at hydroelectric facilities is contributing to the design of more effective fish bypass systems, safer hydropower turbines, and spill bays that produce lower levels of total dissolved gas, resulting in greater protection for fish and continued operation of valuable hydroelectric facilities.

For more information, please contact Duane Neitzel at (509) 376-0602 or via e-mail at duane.neitzel@pnl.gov.