Chief Joseph Kokanee Enhancement Project; Characterization of Pump Flow at the Grand Coulee Dam Pumping Station for Fish Passage, 2004-2005 Final Report.

This report describes a study conducted by Pacific Northwest National Laboratory (PNNL) for the Bonneville Power Administration to characterize the conditions fish experience when entrained in pump flow at the Grand Coulee Dam. PNNL conducted field studies at Grand Coulee Dam in 2004 using the Sensor Fish to measure the acceleration and pressure conditions that might be experienced by fish that pass through pumps at Grand Coulee Dam's Pump-Generating Plant and are transported up into the feeder canal leading to Banks Lake. The probability that fish would be struck by the Pump-Generating Plant's new nine-bladed turbines was also estimated. Our measurements showed relatively low turbulence except in the immediate vicinity of the runner environment. The lowest and highest pressures experienced by the Sensor Fish were 6.4 and 155 psi (the pressure gauge saturated at 155 psi). The probability of strike was also calculated, based on the average length of hatchery-reared juvenile kokanee (land-locked sockeye). Strike probabilities ranged from 0.0755 for 2.36-inch fish to 0.3890 for 11.8-inch fish. The probability of strike estimates indicate that the majority (77%) of recently released hatchery kokanee would be carried through the test pump without being struck and most likely with low risk of injurymore » resulting from pressure and turbulence exposure. Of the 23% that might be struck it is expected that 60% would arrive in Banks Lake without visible external injuries. Thus more than 90% of entrained fish could be expected to arrive in Banks Lake without significant injury, assuming that no kokanee were injured or killed by pressure exposure during passage.« less