Lake Serene / Beverly Park Rd

August 2019 Update

A road closure on Serene Way between 140th St SW to 400 feet north of 140th St SW has been rescheduled to take place between 7 a.m. Thursday, Aug. 22 and 7 p.m., Friday, Aug. 23 to remove and replace a drainage run. The closure will last two days due to additional required utility work. Local access will be available during the closure. No through traffic available, including emergency vehicles, due to open trenching.


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 is to replace degr

aded drainage infrastructure downstream of Serene Way to reduce flooding hazards for Lake Serene homeowners.

​Phase 2

Snohomish County Public Works proposes to replace existing drainage conveyance system between Serene Way and Beverly Park Road. Instream channel work would also occur to improve drainage and reduce stream erosion.

​Environmental Review

Public Works has determined that this project does not have a probable, significant adverse impact on the environment and has issued a Determination of Non-Significance (DNS). An environmental impact statement (EIS) under RCW 43.21C.030(2)C is 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.



  • 2018: Permitting and project design
  • 2019: Construction

Archived Project Updates

View previous project updates from 2017.