The project site is located at lower Sandy Creek, a small tributary to Carpenter Creek south of Mount Vernon. The project was identified as a way to improve habitat quantity and quality for native salmonids and trout while simultaneously reducing risk of flooding for a local landowner. The project focused on restoring natural processes of alluvial fan migration to the site, and is intended to improve drainage, reduce flood risk, improve sediment transport, and restore coho salmon and steelhead habitat at the alluvial fan that has been created where sediments have been deposited at a transition from a relatively high gradient, narrow drainage to low-gradient, unconfined floodplain.
The creek had several features that hindered natural processes. At the apex of the alluvial fan, an undersized culvert under a County roadway (Kanako Lane) obstructed flows and limited sediment transport. Immediately downstream of the culvert, the creek was forced to make a sharp turn to follow its steep-banked channel, which was in a roadside ditch. During high flow events, erosion and scour would damage the road prism, sediment deposition in the vicinity of the culvert would block flows, and a local landowner’s property would be exposed to flooding.
To correct these drainage problems and to restore better habitat for fish, the project involved installing a bridge crossing at the head of the alluvial fan and removing the undersized culvert. The roadside ditch was filled and a meandering channel was reconstructed across the floodplain, accommodating a broader flowpath where channel development and sediment transport processes could naturally function. Large woody debris elements were installed across the floodplain. The project was constructed in 2014 with funding support and in partnership with Skagit County.
This project was constructed in 2014. Site monitoring and stewardship is ongoing.
Primary Project Contact
Eric Mickelson –Restoration Ecologist