Innis Creek Road Flood Mitigation Project

Innis Creek Road passes through a large wetland in which water levels rise above and typically inundate the road surface throughout the late fall, winter and spring. Large sections of the wetland used to be farmed, and landowners maintained ditches to drain their fields. Farming has stopped, and drainage ditches are no longer maintained. As a result, water levels have risen, and the fields have reverted to wetlands.

Role / Services: WSE was retained by Whatcom County to provide specialist hydrology and hydraulic modeling expertise to assist in developing a solution to reduce road flooding. WSE’s primary role is to assess basin hydrology and develop a hydraulic model of the wetland complex to evaluate alternative solutions.

Outcome: WSE developed a HEC-RAS 2D model that helped team members understand how water moves through the wetland and to quantify potential hydraulic benefits of potential solutions. One key requirement of the project is that the solution must not cause 100-year flood levels to rise. The HEC-RAS 2D model was particularly useful in identifying the magnitude and location of impacts, which helped the project team identify acceptable solutions. The County is leading the geotechnical, environmental, and civil design aspects of the project