Couse Creek RM4 Floodplain and Aquatic Habitat Restoration

This project area includes a half mile of Couse Creek beginning at River Mile 4.0. The stream is utilized by ESA-listed Mid-Columbia steelhead, is identified as critical habitat, and is a primary spawning area for the Walla Walla population as identified in the 2009 NMFS Mid-Columbia River steelhead recovery plan. Limiting habitat factors include high water temperature, degraded channel structure lacking habitat diversity and quantity, and fish passage. WWBWC contracted with Anabranch Solutions to install natural wood structures in the project area. The project used a low-tech, process-based restoration approach to jumpstart physical and ecological processes that produce productive, self-sustaining salmonid habitat. The placement of instream structures will produce diverse aquatic habitat types and facilitate floodplain expansion that will enhance the riparian community. Healthy riparian corridors will provide habitat cover, channel shade, and nutrient inputs. By slowing and spreading water, the project will increase the wetted extent of the channel during low flow conditions, which will increase the quantity of habitat available to juvenile steelhead during summer.
While it will take time to realize the full benefits of increased channel shade and floodplain connection, our monitoring data suggest project outcomes are being achieved. The WWBWC received additional BPA funding to complete the installation as designed.

The project aims to restore physical and ecological processes that produce productive salmonid habitat. Placement of instream structures will facilitate floodplain expansion that will enhance the riparian community. Healthy riparian corridors will provide habitat cover, channel shade, and nutrient inputs.
By slowing and spreading water, the project will increase the wetted extent of the channel during low flow conditions, which will increase the quantity of habitat available to juvenile steelhead during summer low flow when stream flow in much of lower Couse Creek is intermittent.
It will also improve channel complexity, creating refugia for juvenile steelhead and enhance spawning conditions for adult steelhead.