Spring fish passage operations began April 3 at federal dams on the lower Snake River and will begin April 10 on the lower Columbia River.
The timing follows requirements in NOAA Fisheries’ 2014 Supplemental Biological Opinion and recent U.S. District Court orders.
This year’s operations call for increased spill — sending more water over dam spillways — up to 125% of state water quality limits in Oregon and Washington for total dissolved gas.
Water supply forecasts for 2026 show near-normal conditions in the Columbia River Basin and below-normal conditions in the Snake River Basin. The April-through-August forecast is 93% of normal at The Dalles Dam and 73% of normal for April through July at Lower Granite Dam.
Higher river flows during spring runoff, combined with increased spill, can create faster currents and elevated water levels below dams. River users are encouraged to use caution and always wear a life jacket.
Additional actions to support salmon and steelhead will continue under current biological opinion requirements.