American Rivers’ seeks to restore hydrologic functions to Roxhill Bog, which is located at the headwaters of Longfellow Creek, a highly urbanized sub-basin of the Green-Duwamish River that flows into an estuary in the south end of Elliott Bay in Puget Sound. Over the past century, the impacts of urbanization have degraded fish habitat, and as the Bog has drained, the quality and quantity of water across the lower reaches of the Green-Duwamish basin have diminished. A study conducted by the City of Seattle in 2000 found that Roxhill Bog groundwater levels are draining rapidly along the northeast corner of the wetland through stormwater and sewer lines. In 2017, the Bog became so dry that it caught fire, further harming an already vulnerable headwaters system.
We will advance key first steps to restore Roxhill Bog’s natural hydrology to enhance its water quality, improve ecological resiliency and benefit salmonid recovery in Longfellow Creek and the greater Green-Duwamish basin. Wetland restoration will reduce direct stormwater discharge and increase groundwater recharge, thereby decreasing water temperature, stabilizing baseflow and improving salmonid habitat conditions in the Longfellow watershed.
Currently, stormwater from the surrounding area is directed into the stream via stormwater drainage. Restoration can be achieved by redirecting stormwater into the wetland. Target outcomes for this project include full saturation of peat soils that currently dry out too frequently and reduced annual water level fluctuations (WLF) to approximately 8-9 inches, with lower fluctuations during growing seasons.
American Rivers seeks a $25,000 grant to work with the Roxhill Bog Wetland Partnership to complete Phase 1 of the project workplan:
• Review existing data; and
• Field surveys and data collection.
Once complete, American Rivers and the Roxhill Bog Wetland Partnership will move forward with future project phases of engineering design, permitting and construction.