Snohomish County
Snohomish County, Washington
Water Quality and Stormwater Management
Snohomish County
Snohomish County, Washington
Water Quality and Stormwater Management
The Little Bear Creek basin in southern Snohomish County supports several species of salmon and trout but is experiencing development pressure in a rapidly expanding area of western Washington. NHC led the development of an NPDES permit-required stormwater management plan for Little Bear Creek to identify stormwater management strategies, as well as complementary instream restoration actions, to maintain or restore conditions that continue to support beneficial uses throughout the stream system. Work included development of a watershed-scale calibrated hydrologic and water quality model as well as optimization modelling to target selection and placement of cost-effective best management practices. Ecological benefit of proposed actions was evaluated using hydro-ecologic metrics with demonstrated correlation to biological indicators. NHC produced a plan identifying capital and programmatic actions to achieve targeted water quality and biologic conditions basinwide and developed conceptual designs for 15 high priority stormwater and instream restoration projects to initiate plan implementation.