With grant funding from the State of California, Waterways was hired by Central Coast Salmon Enhancement and the Coastal San Luis Resource Conservation District to evaluate conditions at the site, prepare potential project alternatives and costs, and develop bid ready engineering drawings. The preferred solution, which was carried through the 100% engineering design phase, consists of a roughened channel approach that seeks to build the streambed up to the elevation of the crossing. Because of the length of the proposed roughened channel (over 600 feet long), pools were designed into the rock ramp approach, thereby providing resting areas for adults moving upstream. The approach taken for this project stretches the boundaries of the roughened channel design. Consequently, Waterways staff have worked closely with California Department of Fish and Game and NOAA Fisheries fish passage engineers and biologists to ensure that the design will function as desired. Waterways has also assisted in development of a comprehensive monitoring plan to evaluate the success or failures of this experimental project.
Pismo Creek Fish Passage Project
Client: Coastal San Luis Resource Conservation District
NOAA Fisheries Recovery Plan for steelhead populations lists Pismo Creek as a high priority system for the recovery of the South Central California Coast Steelhead ESU. Limiting factors to their continued survival in the Pismo Creek Watershed are water withdrawals and fish passage barriers. One of the most significant fish passage barriers in the lower portion of the system is a Union Pacific Railroad Crossing that blocks all life stages of steelhead under all flow conditions. Incision downstream of the concrete culvert railroad crossing has resulted in a 12 foot drop over the concrete structure along with a broad concrete apron through the culvert itself that creates shallow flow under most discharges. A series of Denil fish ladders were installed at the site in the 1980’s but has proven to be ineffective at providing fish passage and requires constant maintenance from debris and bedload.