Dunn Creek is a 10-mile-long tributary to the Kootenai River that provides important spawning and rearing habitat for rainbow trout migrating from the Kootenai River.
A collaborative partnership was established in 2013 including Montana Fish, Wildlife & Parks, the US Forest Service and Weyerhaeuser Company to complete a watershed assessment and prioritize restoration within the Dunn Creek watershed. This assessment identified the single largest source of sediment to Dunn Creek, and estimated that this bank was producing about 168 tons of sediment annually.
Project collaborators developed a restoration plan in 2015, and implemented that plan in 2016 to stabilize the eroding stream bank and reduce fine sediment in Dunn Creek. Restoration efforts included constructing 241 feet of new stream channel consisting of a boulder garden step pool channel with embedded woody debris to enhance channel stability and aquatic habitat.
The newly designed stream channel created a floodplain bench between the new channel and the eroding bank to prevent Dunn Creek from accessing the eroding bank. Permanent cross-sections were established at this site to monitor effectiveness. Results show that stream channel dimensions have not changed and that previously eroding bank has been stabilized.
Large eroding band before project Restored stream channel and floodplain bench Cross section monitoring data after project