Asotin Creek Intensively Monitored Watershed: Lessons Learned from Three Years of Restoration

The Asotin Creek Intensively Monitored Watershed is testing the effectiveness of adding large woody debris at improving wild steelhead production in Southeast Washington. We began monitoring the steelhead population and their habitat in three tributaries to Asotin Creek in 2008. From 2012 – 2014 we added 535 large woody debris (LWD) structures over 12 km of stream. Using an adaptive management approach, we improved our structure designs after each phase of implementation based on the lessons we learned from previous years. The restoration strategy we employed on the Asotin Creek IMW involved the addition of high densities of LWD to the channel. Using this strategy, we have significantly increased wood density (74% increase), pool density (58% increase), and bar development (88% increase) in treatment sites, and provided structural refuge for juvenile steelhead. In addition, we highlight some preliminary fish responses to restoration and outline how our monitoring results will be used to fully assess the effectiveness of large woody debris treatments. The low lost restoration strategy we are using appears to be effective at rehabilitating degraded stream channels and may provide a viable option for reducing the LWD deficit in small to mid-sized streams in the Columbia River Basin.