DESCRIPTION
Seabeck Creek is an Intensively Monitored Watershed (IMW) that lacks instream wood, channel roughness, and off-channel habitats (especially during summer low flows). Available rearing habitats for coho, steelhead, and cutthroat are minimal, and fish passage to upstream spawning and rearing habitats is blocked by a failed fish ladder and undersized culvert. The IMW program has identified several priorities for habitat restoration in Seabeck Creek. This project seeks to address the top priority Seabeck Holly Rd NW fish passage to improve access to spawning habitats for all salmon stocks listed above and wood placement to improve rearing conditions for Seabeck steelhead, coho, and cutthroat. Wood placements will also restore channel geomorphology and floodplain functions by improving sediment retention, adding diversity to instream habitats, and creating off-channel habitats.
The primary goal of this project was to design a restoration project for Seabeck Creek that fits within the framework outlined in the Hood Canal IMW Study Plan, to remove fish passage barriers and restore stream connectivity from downstream to upstream, and to increase sediment storage capacity and channel roughness from upstream to downstream. This project design addressed Hood Canal IMW priorities 2 and 3 for Seabeck Creek, with the following ultimate goals: (1) Restore fish passage to upstream habitats by removing downstream barriers; (2) Improve the quality of and accessibility to spawning habitats by removing barriers low in the watershed and restoring sediment processes; (3) Increase the amount of available rearing habitat for salmonids by adding habitat complexity in the form of in-stream wood; (4) Slow the flow of water (or restore to a more metered flow), improve sediment retention in the system overall, and restore floodplain functions where possible. The project objectives were to complete a preliminary design for Seabeck Creek habitat restoration that includes the following key components: (1) Culvert replacement with an appropriately-sized structure to allow passage of fish, wildlife, wood, and sediment; (2) Wood placement upstream and downstream of the culvert to control sediment movement and add habitat complexity; (3) Wood placement just below Hite Center Rd, where flooding has scoured the channel down to till to retain sediment, promote pool formation, and restore stream geomorphology and sediment processes.