FISHBIO fabricated two large lifting systems in 2018 to help the Santa Clara Valley Water District (SCVWD) remove Riverwatcher automated fish counters from 15-ft.-tall fish ladders for cleaning and maintenance. SCVWD is using the Riverwatchers to monitor steelhead and other species using the fish ladders to migrate up creeks in California’s Silicon Valley. We fabricated two 20-ft.-tall aluminum “elevators” that utilize electric winches and stainless-steel cables to raise and lower a Riverwatcher on a metal platform with the push of a button. This gives staff the ability to service the Riverwatcher devices without needing to encounter the potentially dangerous conditions inside the fishway. While designing the system, FISHBIO had to consider personnel safety, preventing delays to fish migration, and avoiding excessive water velocity, turbulence, or air bubbles around the Riverwatcher.
The elevators were designed to slide into place without using any fasteners during installation to avoid drilling into the existing fishways, meaning staff did not need to enter the fishways to secure the structures. Our crew also constructed a 10-ft. by 10-ft. weir panel to hold the elevators in place inside the fishways, and created a series of stacking picket weir panels that biologists can easily remove or replace with wooden planks to guide fish into the Riverwatcher in response to changes in flow and gauge height. We were able to repurpose an existing solar panel array at the installation site to power the Riverwatcher’s 24-V computer. The uniqueness of the elevator construction required extensive coordination with SCVWD engineers, which resulted in the successful design and installation of the structures.
