Entiat 4.6 (1D Reach) Prel. Design

This is a preliminary design phase project. The project will aim to address raising temperatures and increased sediment inputs into the Mills 05 Reach of the Entiat River. Water temperature issues will be addressed through enhancing existing riparian habitat along vegetated banks and restoring riparian corridors along cleared sections of bank. Increased sedimentation will be addressed by the addition of Engineered Log Jams (ELJ). The design phase of this project will identify the location and type of ELJ structures that would provide the greatest benefit for redirected stream flow and bank protection, for bank sections that are currently experiencing increased erosion rates. Results of the project would provide a benefit to Steelhead and Spring Chinook populations. Bureau of Reclamation Lower Entiat Reach Assessment identified the Mills 05 Reach to support all life stages of Steelhead. Steelhead spawning, fry and smolt received medium rankings and Summer and Winter Rearing was identified as High. Spring Chinook Winter Rearing was classified as High. Lower instream temperatures will result from increased quality and quantity of riparian vegetation along the banks and placement of ELJ structures will aid in lower total suspended solids and sediments through reduction of bank erosion.

The goals of this project are to develop preliminary design elements that will provide increased shading to the 1D reach of the Entiat River and increase habitat complexity and diversity for steelhead spawning and juvenile rearing and holding for steelhead and chinook salmon.