Stitch Creek/South Davies Road Culvert Baffles
Snohomish County, WA

The South Davies Road culvert crossing for Stitch Creek provided a barrier to fish passage due to high velocities and flow depths in the culvert. Retrofitting the culvert using a baffle system was selected as the preferred remedy due to the high cost of replacement and good structural condition of the existing culvert.

KPG and Snohomish County staff developed a system of pre-fabricated steel baffles that could be assembled outside of the actual culvert and pulled into place using a winch and chain. The chain and baffle assembly was secured to the upstream concrete apron using expansion bolts with no fixed points required within the culvert barrel. A trash rack was installed to reduce the risk large debris entering the culvert and collecting on the baffles.