Caltrans District 7 North Fork Matilija Creek Geomorphology, Fish Passage, and Engineering

The California Department of Transportation (Caltrans) District 7’s North Fork Matilija Creek project involved removing the existing rock slope protection on State Route 33 at Postmile 15.7/15.8 in Ventura County and replacing it with a soil nail wall. This will stabilize the roadway to prevent future erosion and scouring, and protect public safety.


CWE performed geomorphic assessment, fish passage analysis, and stream restoration design to naturalize a stream for fish passage and habitat, reduce flow velocities, and solve erosion issues along the highway embankment. This project involved an extensive permitting process with the National Oceanic and Atmospheric Administration (NOAA), California Department of Fish and Wildlife (CDFW), and Caltrans. CWE was able to obtain agency approval from NOAA in one-third of the required amount of time. This reduced the schedule for implementation, decreased cost, and preserved funding from the Federal Highway Administration.