Improving Passage for Fish

Upper Columbia spring Chinook salmon and steelhead trout pass through seven to nine dams on their way to and from the ocean, depending on where they were born. Improvements to hydropower dams and their operation have ensured that most fish pass through successfully and standards for passage survival are met.

Although much progress has been made to better understand and improve survival in the Columbia River, some uncertainties and opportunities for improvement remain Columbia River dam operators used flexible spill operations in 2019-2021 to increase survival of young fish as they migrated downstream. This practice increases flows through spillways instead of electrical turbines during important times for young fish movement. It is too early to tell what effect those changes have had on survival rates.

Fish cannot travel above Chief Joseph Dam, cutting off 40 percent of historic habitat in the Columbia River. Efforts are underway to reintroduce anadromous fish into this blocked habitat.

For more about hydropower in this region, see the Hydropower Background Summary.

Visit the Salmon Data Hub for more of the data behind the indicator charts and graphs used throughout this site.