The Status of Anadromous Salmonid Passage Strategies at Hydroelectric Projects on the Snake and Columbia Rivers

Seven species of Endangered Species Act-listed salmon and steelhead pass the federal dams on the lower Snake and Columbia rivers on their way to the Pacific Ocean. These dams, part of the Federal Columbia River Power System (FCRPS), have been equipped with some of the most sophisticated fish passage facilities in the world.  Since 2008, the U.S. Army Corps of Engineers has installed surface passage structures, improved outfall and bypass systems and tailored spill patterns at the dams based on research and monitoring. In the Upper Columbia River Basin, Public Utilities have implemented a variety of fish passage actions as per their Habitat Conservation Plans. NOAA Fisheries’ biological opinion for operation of the FCRPS prescribes survival targets at hydroelectric dams to protect listed fish.  Habitat conservation plans have similar performance goals.  Empirical testing ensures that goals are being attained, or additional actions are implemented and tested. We will look at findings from several years of monitoring and evaluations to track the performance of the configuration and operations improvements to the FCRPS and PUD dams aimed at improving juvenile and adult salmonid survival. We will also address a variety of factors affecting survival at the dams. Based on a complex of tag-recature studies using both hatchery and wild fish, researchers are able identify preferred dam passage routes and inform continual improvements to those routes to improve survival. More broadly, reach-scale survival studies help identify management actions that contribute to better survival through the reservoirs.