Planning “total restoration” of a pilot watershed

Year: 2020
Presenter/s: Reid Camp
Symposium Session: 2020 - 07 Selling the solution: Piloting projects and stakeholder engagement
Topics covered: beavers, community involvement, estuary, fish-cutthroat, fish-salmon, fish-steelhead, lessons learned, monitoring, riparian, and stream


Reid Camp

The Middle Nemah River drains approximately 6,000 hectares (nearly 15,000 acres) into Willapa Bay (Washington), and is important habitat for chum (Oncorhynchus keta), Chinook (O. tshawytscha), coho (O. kisutch), and steelhead (O. mykiss). However, legacy impacts from construction of a railroad within the channel migration zone, stream cleaning, and other land-use activities have impaired salmonid productivity in this sub-basin. Willapa Bay Lead Entity (WBLE) and Pacific Conservation District (PCD) recently selected the Middle Nemah as a pilot watershed, to demonstrate potential for “complete restoration.” Under this emerging model of restoration, the primary goal is implementation of restoration actions across an entire watershed, at a level sufficient to restore currently impaired river and riparian functions, within a relatively short timeframe (five years in this case). Working with a team of stakeholders that included landowners (WDNR and Hancock Natural Resources Group), WBLE, PCD, WDFW, the Willapa Bay Fisheries Enhancement Group, Coast Salmon Partnership, and our partners Biohabitats, we developed and implemented a rapid habitat protocol to survey the mapped current anadromous zone within the watershed, approximately 35 km (22 miles) of mainstem and tributary channels. Survey results were then analyzed and coupled with existing land-use data to develop an assessment of current river and riparian functions and processes throughout the watershed, identify process impairments, and develop recommendations for a suite of actions that would mitigate these impairments. In collaboration with the stakeholder group, these actions were then prioritized along a simplified scoring schema focusing on ecological improvement. A single project was then brought forward to the preliminary design phase, and concepts were developed for total restoration of the entire watershed. Recommended restoration actions included a combination of engineered approaches and “low-tech process-based” restoration (LTPBR). Results from this effort suggest that a comprehensive plan for restoration of moderate-sized river sub-basins is possible, at a reasonable economic cost.