Santa Clara Gravel Augmentation & Steelhead Habitat Improvement
HELIX is providing fisheries expertise for steelhead spawning habitat improvement in all seven steelhead-producing streams in Santa Clara County. HELIX fisheries scientists reviewed existing documentation to determine and assess biological criteria currently being used for evaluating Santa Clara Valley streams and developed scoring criteria to prioritize candidate stream segments. Level 2/3 habitat mapping field efforts were then performed. Proposed gravel augmentation and large woody material placement locations were compared with the criteria developed for suitability and prioritization of locations. Santa Clara Valley stream channels are generally characterized as being incised, due to historic mining and other land use. The project consists of developing a gravel augmentation and large woody material placement program for eight anadromous steelhead streams in Santa Clara County, and to identify and prioritize gravel augmentation and large woody material placement sites for steelhead habitat restoration, based on sound geomorphology, hydrology/hydraulic engineering, and ecological principals, including steelhead spawning/rearing requirements and limiting factor analyses. Work is being performed as a subcontractor with the Santa Clara Valley Water District as the lead agency.