Sauk Prairie Road / Mouse Creek Drainage Improvement Project


Snohomish County Public Works has begun work to alleviate flooding over Sauk Prairie Road, approximately three miles northeast of Darrington. Following high precipitation events, road flooding occurs due to the buildup of sediment in Mouse Creek. During the summer of 2019, county crews removed a berm and excavated 250 linear feet of sediment from Mouse Creek. A second phase of the project will include the excavation of an additional 500 linear feet of sediment from the channel. Completion of this project will reduce road flooding and improve passage for Coho and other species of fish.


  • 2017: Preliminary design 
  • 2018: SEPA, permitting and design of Phase 1  
  • 2019: Construction of Phase I 
  • 2020: SEPA, permitting and design of Phase 2
  • 2021: Construction of Phase 2

Environmental Review

On May 10, 2018, Public Works determined that the first phase 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.

A second environmental review and comment period are currently planned for 2020.