Clear Creek Floodplain Restoration, Silverdale, Kitsap County, WA

NSD provided stream and floodplain restoration designs for a 30-acre site in response to repeated flooding in downtown Silverdale, WA. To confirm that restoration alternatives would provide flood relief throughout the project area, NSD used HEC-RAS and sediment transport analysis to assess the preliminary design. In order to identify the preferred channel location, avoid impacts to existing high-quality wetlands, and enhance degraded wetland features, NSD delineated and mapped all wetlands. Products included a wetland features map with locations of vegetative communities, buffer zone and riparian and channel enhancement plans. Project success required that NSD staff lead complex negotiations with multiple stakeholders including the County, project neighbors, trail users, the Suquamish Tribe, WDFW, and USACOE to address conflicting priorities. Final designs for stream corridor restoration, wetland and floodplain habitat, fish passage at road crossings, and recreation trails were completed Summer 2015 and will be constructed Summer through Fall 2016.