River Flows

Photo of a stump in a river

The HCP establishes an instream flow management program to provide beneficial conditions for salmon and steelhead in the Cedar River downstream of Chester Morse Reservoir. Sockeye salmon, coho salmon, Chinook salmon and steelhead inhabit the Cedar River and are of special concern in water and hydropower operations. In order to keep enough water in the Cedar River for fish, these are the things the City does:

  • Guarantee minimum flows so fish can access habitat, spawn and grow in the Cedar River.
  • Decrease flows slowly, so fish and other aquatic organisms can sense the change and avoid getting trapped when flows decrease.
  • Conduct scientific research on how much flow is necessary to benefit fish in the Cedar River.
  • Fund facility improvements at City of Seattle dams and powerhouses and the Ballard Locks, a USACE Facility.
  • Fund aquatic habitat protection and restoration in the Cedar River.

Learn more about river flows in the latest Instream Flow Annual Compliance Report or contact Karl Burton.


Project Spotlight: Salmon Redd Scour Study Report

Redd scour can cause high mortality rates for incubating salmon. In order to determine the flows at which redd scour starts, researchers deployed scour monitors in known spawning habitats throughout the Cedar River. Contact Karl Burton for more information.