This project retrofitted a concrete flood conveyance channel adjacent to the Highway 101 culvert on Strawberry Creek near McKinleyville in Humboldt County by installing 13 angled concrete baffles to create a functional fishway, restoring 5 miles of upstream spawning and rearing habitat for steelhead, coho salmon, coastal cutthroat trout, and lamprey species.
Location: Strawberry Creek, a small coastal drainage near McKinleyville, Humboldt County. The project site is located at the Highway 101 crossing adjacent to Clam Beach, where a concrete flood conveyance channel functioned as a total barrier to upstream fish passage. Strawberry Creek drains directly to the Pacific Ocean.
Historical Fish Presence: The watershed currently supports steelhead trout (O. mykiss), coastal cutthroat trout (O. clarkii clarkii), and western brook lamprey (Lampetra richardsoni). Coho salmon (O. kisutch) were historically present and a population of Pacific lamprey (Entosphenus tridentatus) is suspected. The Highway 101 crossing was identified as the highest priority barrier in the watershed due to the severity of the concrete channel obstruction and the volume of available upstream habitat.
Project Lead: Trout Unlimited – North Coast Coho Project
Project Partners: US Fish and Wildlife Service (Dan Gale, Project Officer), Michael Love & Associates (Engineering), Pacific Earthscapes (Construction), Ross Taylor & Associates (Fish Biology), Humboldt County and CalTrans (Landowners)
CFPF Funding: $31,055
Project Description: A 2014 fish passage assessment by Ross Taylor & Associates identified the concrete grade control channel upstream of the Highway 101 culvert as a total barrier to all life stages of salmonids, despite the culvert itself being passable. USFWS retained Michael Love & Associates to develop a retrofit design, completed at 70% in 2017. The final project installed 13 cast-in-place angled concrete baffles, each 1.2 feet tall and spaced 12 feet on center, skewed to shunt water and debris to one side while maintaining a fish passage corridor on the other. The design increased water depth and reduced velocity to meet fish passage criteria without increasing flood risk to the adjacent Central Avenue roadway. Construction was completed by Pacific Earthscapes in October 2022, with fish exclusion and relocation conducted prior to dewatering. A minor design adjustment was made at one baffle location to accommodate a CalTrans bank repair, with negligible impact on channel hydraulics.
Expected Completion: January 2023 (contract term: September 1, 2020 – January 31, 2023)
Project Effectiveness: Post-construction survey by Michael Love & Associates confirmed 100% passable conditions for adult and juvenile salmonids and lamprey at all life stages, restoring access to 5 miles of upstream spawning and rearing habitat. Photographic monitoring was conducted before, during, and after construction. Baffles were reported to be functioning as designed at project close.
