Increased Spring Spill Begins at Lower Snake River Dams

Federal court order requires higher spill levels to aid migrating salmon and steelhead

Apr. 9, 2026 at 1:09am

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A highly textured, sweeping abstract painting in earthy tones of green, blue, and brown, featuring geometric arcs, concentric circular patterns, and precise botanical or physical spirals, conceptually representing the complex interplay of water, power, and migratory fish in the Lower Snake River ecosystem.An abstract visual representation of the increased spring spill at the Lower Snake River Dams, a critical annual event for the survival of endangered salmon and steelhead populations.Pullman Today

The U.S. Army Corps of Engineers has begun the annual spring spill over the Four Lower Snake River Dams in southeastern Washington, following a recent federal court order requiring increased spill levels this season. The increased spill helps move young salmon and steelhead migrate downriver by diverting water away from the dams' turbines.

Why it matters

The spring spill is a critical annual event for the survival of endangered salmon and steelhead populations in the Snake River basin. Higher spill levels can improve fish passage and reduce mortality rates during the crucial downstream migration period.

The details

The U.S. Army Corps of Engineers is overseeing the increased spring spill, which began last week. The action diverts more water over the top of the dams rather than through the turbines used for power generation, creating faster currents and higher water levels below the dams. River users are being advised to exercise caution during this period.

  • The annual spring spill began last week.
  • The increased spill levels are in effect for the current spring migration season.

The players

U.S. Army Corps of Engineers

The federal agency responsible for managing the operation of the Four Lower Snake River Dams and overseeing the annual spring spill.

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What’s next

The increased spill levels will continue through the spring migration season, with the U.S. Army Corps of Engineers monitoring river conditions and providing updates to the public.

The takeaway

The higher spring spill at the Lower Snake River Dams is a court-ordered measure to aid the survival of endangered salmon and steelhead populations, demonstrating the ongoing efforts to balance hydropower generation and environmental protection in the region.