Passage of Juvenile Chinook Salmon and other Fish Species through Archimedes Lifts and a Hidrostal Pump at Red Bluff, California

Abstract

Fish were passed through two large Archimedes lifts and a large Hidrostal pump at the U.S. Bureau of Reclamation's experimental pumping plant on the upper Sacramento River, California. Two of the pumps were run concurrently during trials to compare their effects on hatchery-reared juvenile chinook salmon Oncorhynchus tshawytscha. In each trial, control samples were released at pump outfalls, and treatment samples were inserted into the intake of each pump. Fish in samples were collected in downstream holding tanks. In 27 trials comparing the two Archimedes lifts, mean survival for paired control and treatment groups was 98.3–99.0% for both lifts. Effects from pump passage were not detected for either lift at α = 0.05. In 40 trials comparing the Archimedes lifts and Hidrostal pump, mean survival for paired control and treatment groups was 96.5–99.5% for both pump types. Effects of passage through these small pumps were detected: 0.9% for the Archimedes lifts and 2.4% for the Hidrostal pump. To examine their effects on riverine fish, the two Archimedes lifts and the Hidrostal pump were run concurrently for 24 h during 24 trials. The pumps entrained 3,337 juvenile chinook salmon and 2,773 fish of 27 other species. Survival per pump for riverine chinook salmon and the other species taken collectively ranged from 94% to 98%, and among-pump differences were not statistically significant. Postpassage examinations of chinook salmon from experimental trials and entrained riverine fish revealed a very low incidence of potentially debilitating injuries among surviving individuals. Because of these results and supporting data in other studies, this pumping technology is being considered for use at other water diversion sites in California to protect fisheries resources.