DESCRIPTION
Asotin County Conservation District restored juvenile fish passage over Headgate Dam, located in the lower reaches of Asotin Creek. Headgate Dam is owned by Asotin County and was identified as a partial barrier to ESA listed juvenile Chinook, steelhead & bull trout. The project reach is identified as a major spawning area and priority restoration reach in the Snake River Salmon Recovery Plan. The barrier was listed as an action in the Snake River Three Year Work Plan for Salmonid Recovery and was considered an imminent threat and high priority.
Historically, the dam was outfitted with failed fish passage improvement measures on at least 3 occasions before it was abandoned and became the property of Asotin County. Despite these efforts, a drop of 1-1.5m remained, producing a barrier to juvenile salmonids and other small fish. Asotin County Conservation District restored fish passage by cutting a notch in the concrete dam (approximately 20 ft. wide x 3.2 ft. deep) and constructing a roughened channel upstream of the dam to maintain channel stability and prevent head cutting.
Headgate Dam has historic and cultural significance to the Asotin County residents so extensive effort was taken to involve county residents in the discussions and process of selecting a preferred design alternative. Residents wanted to ensure that the passage issue was addressed in a way that would maintain as much of the historic qualities of the dam as possible. Several public meetings were held in which 6 conceptual design options (developed by WA Department of Fish and Wildlife) were presented and a preferred design was selected and approved by the Asotin County Commissioners.