Tenmile Creek PA 68.1 Construction

The Asotin County Conservation District completed the Tenmile Creek Project Area (PA) 68.1 restoration project. 40 wood structures were installed promoting overbank flow, increasing in-stream complexity, and improving sediment and water retention. The total reach length was 0.7 miles. Steelhead is the priority species that will benefit from the project for migration, spawning, and rearing life stages.



PCSRF FY 2018 funds were spent within the award period.

The project goals are to protect recovering riparian and fluvial processes between RM 3.2-3.3 and RM 3.5-3.8, add LWD to the channel and floodplain, improve access to floodplain, improve access to flood channels, and promote overbank flow. Improving access to flood channels will improve floodplain connection. Increasing the regularity of floodplain inundation will help kickstart riparian recovery and promote lateral migration. Adding LWD to the channel would improve hydraulic and geomorphic variety, promote overbank flows, and increase sediment and water retention. Adding LWD the floodplain to conjunction with improved floodplain access will promote fine sediment deposition and improve floodplain conditions. Biological Benefits to Steelhead (at all life stages): There are few pockets of recovering riparian areas in Tenmile Creek, so protecting these areas with higher ecological function and extending their coverage should be a priority. Adding LWD to the channel would improve habitat and increase the prevalence of key habitat features such as pools, cover, suitable spawning areas, margin-attached bars, and concealment opportunities. LWD may also increase water retention and improve hyporheic exchange which could extend summer base flows and buffer stream temperatures downstream. Improve floodplain access and LWD in the floodplain would help kickstart riparian recovery and help connect pockets of higher quality riparian areas.