Fifteenmile Creek Large Wood Enhancement

Fifteenmile Creek is a perennial Wild and Scenic River that originates near Lookout Mountain in the Mt. Hood National Forest. From the Forest Boundary, it flows ENE 12.3 miles to the town of Dufur, OR and eventually empties into the Columbia River just below The Dalles Dam. The project area is located within the Fifteenmile Creek Headwaters HUC-12 subwatershed (170701050301) which is primarily located in Wasco County on the National Forest. The creek enters privately owned and city of Dufur managed lands in its downstream reaches. This subwatershed was identified as the highest priority for restoration efforts in Fifteenmile watershed restoration plans (Rossel, 2010; WCSWCD 2003) and by federal, tribal, and state partners with interests in the health and function of the watershed. The subwatershed has been impacted by forest harvest, road construction, recreation, land use conversions and water diversions. Historical forestry practices reduced natural large woody material (LWM) in the stream channel. Some natural recovery of large wood deficits has occurred in upstream reaches of the creek on the National Forest within and near wilderness areas but downstream reaches that have had more intensive management still lack large wood. The lack of stream channel and floodplain large wood has led to a loss of stream channel and floodplain processes. The Wasco County Soil and Water Conservation District will partner with The Mt. Hood National Forest to add large wood at 10 project sites in Fifteenmile Creek on the National Forest to improve channel and habitat complexity for steelhead and other aquatic fauna such as Pacific Lamprey, interior Columbia redband trout, and Cope’s Giant Salamanders. Due to a lack of roads available to access sites along the creek where large wood will be added, helicopters will be used to place wood in the stream and its floodplains.

The purpose of this project is to restore designated critical aquatic habitat as an aid to the recovery of mid-Columbia steelhead. Multiple steelhead life history stages spend a portion of their lives in the project reach and will benefit from project implementation. Spawning surveys have located steelhead redds within the project reach. Though barriers to upstream migration in the creek have been removed over the years, spawner abundance in the higher gradient reaches of upper Fifteenmile Creek (12% of 2013 spawners; Poxon et al. 2014) is lower than in downstream reaches. Large wood added to project reaches would improve spawning habitat for steelhead by creating new pools and reinforcing existing pools, thereby increasing pool quality and quantity. This will add channel habitat complexity at all sites and reactivate or increase flow volumes in existing side channel habitat at 60% of the project sites.