Mill Pond Dam Removal, Metaline Falls, WA
Rocky led the stream and floodplain restoration designs over 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 + CGS 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 + CGS delineated and mapped all wetlands. Products included a wetland features map, including locations of vegetative communities and buffer zone and riparian and channel enhancement plans. Project success required that NSD + CGS staff lead complex negotiations with multiple stakeholders including the County, project neighbors, trail users, the Suquamish Tribe, WDFW, and USACOE to address conflicting priorities.
Construction elements include a 5,000 ft. channel, installation of over 500 logs, excavation of 30,000 CY of material to restore the floodplain, removal of 1,500 LF roadway and installation of 3 bridges. Rocky led the restoration design, managed a team of five subconsultants, led the permitting efforts and supervised construction of the $2.3 million project which was constructed in 2016. The project was selected for the “Vision 2040” by the Puget Sound Regional Council in 2017 for its ability to ensure a sustainable future as the region grows.