IIHR contracted with Grant County Public Utility District No. 2 (Grant Co. PUD) in the state of Washington to provide hydraulic modeling and analysis to improve the design of fish passage structures for its hydroelectric dams, including Priest Rapids on the Columbia River.

IIHR has collaborated with Grant Co. PUD, the U.S. Army Corps of Engineers, and other major hydroelectric utilities to increase the survival of fish passing hydropower dams in the Pacific Northwest, especially on the Snake and Columbia Rivers.

Researchers worked to reduce the number of salmon that fall prey to the harsh environment within the hydroelectric turbines or to the high levels of nitrogen absorbed by the river as water mixes with air after passing through the spillway gates.

IIHR’s researchers and technicians have constructed several large-scale laboratory models over the years, including Wanapum, Priest Rapids, and others, to laboratory-test proposed fish-passage structures prior to construction. The models complement IIHR’s advanced computational fluid dynamics (computer simulations) to simulate hydraulic performance of proposed or existing fish passage facilities.