The large concrete culverts that carry Chico Creek under SR 3 were constructed when the highway was being built over 50 years ago. While the current system allows water to pass, it is very difficult for fish to navigate as they return to spawn. The culverts also present maintenance challenges as they can clog from debris and cause backups and flooding upstream. Removal of the fish passage barriers along the unnamed tributary to Chico Creek and Chico Bay would allow access to about 21 miles of potential habitat.
Chico Creek and the unnamed tributary at Chico Way Northwest have five undersized, sloped, and otherwise inadequate culverts that act as barriers to fish passage. The narrow culverts also dramatically change the angle of how Chico Creek flows into Chico Bay and Dyes Inlet.
The unnamed tributary to Chico Creek runs via corrugated metal pipes under Chico Way Northwest, the southbound SR 3 exit to Chico Way Northwest, Chico Way Northwest on-ramp to southbound SR 3, and an abandoned maintenance access road.
Chico Creek serves as a home for native fish species including Chinook salmon, chum salmon, coho salmon, coastal cutthroat and steelhead trout, sculpin, and western brook lamprey. When the project restores access to the unnamed tributary, resident and migratory native fish species could inhabit the tributary. Removing the barriers will benefit these fish populations.
The end result
The enhancements and barrier removal at Chico Creek will:
- Improve access to 21 miles of potential habitat
- Allow more fish access to spawning habitat
- Build a replicated natural streambed for Chico Creek
- Reduce future maintenance costs due to culvert blockages by removing undersized culverts
- Minimizing risk for upstream flooding
Construction crews will make physical changes to the highway that will help replicate natural stream conditions. The materials used for the new stream alignments replicate a natural streambed by using a mix of gravel and varying-sized rock.
WSDOT has worked for nearly three decades to improve fish passage and reconnect streams to help keep our waterways healthy. The new channel will create critical new habitat for the salmon life cycle. The stream is home for young fish until they are mature enough to make it to the ocean. The habitat will also serve as a place for spawning salmon to return and lay eggs for the next generation.