Lake Serene is located in unincorporated Snohomish County, west of Highway 99 between Mukilteo and Lynnwood. Public Works has been working with community residents to mitigate flood risk. Previous to flooding that occurred in the winter of 2017, Snohomish County had assessed the condition of the lake’s outfall system, located on private property, and found it was in a state of disrepair. It was later determined that it had collapsed.
Snohomish County Public Works devised three alternatives for residences living around the lake. In March 2017, Snohomish County Council approved a private-public cost share to improve drainage flow and ease high lake levels.
The project included two phases. The first phase was completed in September 2017 and connected the lake to the bypass system that was built in the winter of 2017.
The second phase of the project replaced degr
aded drainage infrastructure downstream of Serene Way to reduce flooding hazards for Lake Serene homeowners.
Snohomish County Public Works replaced the existing drainage conveyance system between Serene Way and Beverly Park Road. Instream channel work also occurred to improve drainage and reduce stream erosion.
Public Works determined that this project did not have a probable, significant adverse impact on the environment and issued a Determination of Non-Significance (DNS). An environmental impact statement (EIS) under RCW 43.21C.030(2)C was not required. This decision was made after review of SEPA documents and other information on file with this agency. These documents are available for public review upon request.