DESCRIPTION
The Clearwater River Large Woody Debris Project addressed major limiting habitat factors and impaired processes on the Clearwater River through strategic placement of large wood structures. A watershed scale geomorphic assessment informed the design and placement of the structures based upon current and historic floodplain characteristics, local geology, and basin-wide topography. The project increased spawning and rearing capacity of the watershed through in-stream wood placement between river mile 2.3 and 3.8 for Spring Chinook, steelhead, coho, pink salmon and cutthroat and bull trout species. The primary objectives of the project were to: dissipate flood energy, activate the floodplain and recharge groundwater, increase pool habitat, increase instream structure and refuge habitat, improve riparian function, provide shade, and reduce water temperatures. Basic monitoring efforts have confirmed that the project is functioning as designed. The log structures are serving to trap and sort significant amounts of sediment resulting in a well connected floodplain, narrower multi-threaded channels with deeper pools, and finer, spawning sized gravels retained within the project reach. Post construction monitoring in 2016 showed the constructed log jams were, on average, recruiting 33 new logs per jam.
The South Puget Sound Salmon Enhancement Group addressed major limiting habitat factors and impaired processes on the Clearwater River through strategic placement of 18 large wood structures. The Clearwater River flows just over 10.5 miles to the confluence with the White River at river mile 35.3. The upper five miles flow through the Mount Baker Snoqualmie National Forest. The lower five miles flow through the White River Tree Farm, where timber harvest and logging roads have affected the natural morphology of the river. The project reach is located between river mile 2.3 and 3.1.
A watershed scale geomorphic assessment was completed to help inform design and placement of wood structures based upon current and historic floodplain characteristics, local geology and basin-wide topography. The overall goal of the project was to increase spawning and rearing capacity of the watershed for Spring Chinook, steelhead, coho, pink and cutthroat trout species. The primary objectives achieved by the project were: increased stability of the watershed, dissipatation of flood energy, activation of the floodplain, increased pool habitat, increased instream structure and refuge habitat, improved riparian function including increased shade, and reduced water temperatures.
