DESCRIPTION
A series of cascades within the South Fork Skokomish Canyon are a natural partial barrier to upstream migration that were historically known to be passable by steelhead, bull trout, and early-timed Chinook. These cascades were primarily passable when flows were elevated due to snow-melt runoff. Decreased snow-melt runoff has made passage over the cascades more difficult. Engineers for WDF have concluded that some type of corrective action will need to take place to facilitate safe passage over the cascades. This project will assess the four sites identified by WDF to determine the passability at various flows and develop design concepts for fish passage improvements if necessary. Fish passage in this location will be necessary for successful re-introduction of Chinook into the upper South Fork.
A series of cascades within the South Fork Skokomish Canyon are a partial barrier to upstream migration that were historically known to be passable by steelhead, bull trout, and early-timed Chinook. These cascades were primarily passable when flows were elevated due to snow-melt runoff. Watershed changes have resulted in decreased passibility at these cascades. Prior to initiation of this project; engineers for WDF concluded that some type of corrective action will need to take place to facilitate safe passage over the cascades. This project assessed the South Fork Canyon to determine the passability at various flows and developed a design concept for those cascades determined to be substantial barriers to migration. Fish passage improvement measures in this location will be important for successful re-introduction of Chinook into the upper South Fork Skokomish River.
NOTES
From Skokomish M&AM Results Chain "Restore upper watershed conditions in South Fork and major tributaries"; substrategy "Improve adult passage at the gorge cascades"
