Hydropower

Dams Continue to Impair Access to Important Fish Habitat

Dams on the Lewis and Cowlitz Rivers continue to impair fish access to large areas of historically productive habitat. Dams cause more issues than just impeding fish passage, including preventing natural processes such as gravel and wood movement, muting habitat-forming floods, and inundating spawning and rearing habitat under reservoirs. Reintroducing salmon and steelhead trout to these watersheds is a high priority for regional recovery, especially for spring Chinook salmon: four of the seven spring Chinook salmon populations rely on habitat above dams in the Lewis and Cowlitz basins.

As a condition of receiving federal licenses to operate hydropower dams, PacifiCorp, Cowlitz Public Utility District, and Tacoma Power agreed to construct and operate fish traps to gather and transport at least 95 percent of juvenile salmon downstream of the dams so they can migrate to the ocean. None of the traps have met this requirement, and low trap effectiveness is preventing reintroduction success. Delays in building facilities in the Lewis River basin has further set back recovery.

The Lower Columbia Fish Recovery Board partners with Tacoma Power to manage the Cowlitz Restoration and Recovery Grant Program for habitat projects in the basin. Board staff also advises the Fisheries Technical Committee, which develops and implements fishery, hatchery, and reintroduction programs. The board also partners with PacifiCorp in the Lewis River watershed, assisting with mitigation and reintroduction plans for salmon and steelhead.

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