DESCRIPTION
This Middle Boise Creek restoration project would expand and restore juvenile salmonid rearing habitat by creating additional channel area, placing instream LWD, and enhancing riparian buffers. Spring and fall-run Chinook, steelhead, bull trout, and other salmonid species use this stream. The1,600 linear feet of channel restoration will be located on the north side of a forested hillside of mature cottonwood,maple and alder. A mosaic of springs and slope wetlands is located adjacent to the channel, between the left bank and toe of the hill which will enhance connections to the channel. Aquatic habitat complexity will increase by carefully excavating to expand channel areas around existing mature trees. LWD will be placed and embedded into the channel and banks to form and sustain pools and to provide structure and cover. This expanded channel/ floodplain habitat will receive immediate overwater shade and organic litter from the adjacent forest. Retaining existing trees, intercepting local groundwater, and creating habitat structure with LWD are expected to make habitat functional for juvenile fish immediately following construction. By excavating the bank and increasing roughness in the channel, we expect more frequent connectivity and inundation of floodplain wetlands, providng valuable off-channel fish habitat.
King County completed preliminary design for a restoration project on Middle Boise Creek. The restoration project as designed will expand and restore juvenile salmonid rearing habitat by creating additional channel area, placing instream LWD, and enhancing riparian buffers. The White River was listed as the 8th most endangered river in the United States by American Rivers (2014). Boise Creek is the most important tributary of the White River downstream of Buckley Diversion Dam. Spring and fall-run Chinook, steelhead, and four other salmonid species use this stream. The 800 feet of channel restoration will be located mostly on the south side of the stream and the north side of a forested hillside. LWD will be placed and embedded into the streambed and stream bank to form and sustain pools and to provide structure and cover. This expanded channel/ floodplain habitat will receive immediate overwater shade and organic litter from the adjacent hillside forest. Retaining existing trees, adding streambed gravel, and creating habitat structure with LWD are expected to make habitat functional for juvenile fish.
