Characterization of Pump Flow at the Grand Coulee Pumping Station for Fish Passage, 2004

This report describes a study conducted by PNNL for the Bonneville Power Administration to characterized the conditions fish experience when entrained in pump flow at the Grand Coulee Dam. PNNL used the Sensor Fish to measure the acceleration and pressure conditions that might be experienced by fish who are pulled through the pumps and turbines at Grand Coulee Dam's pump generation station and transported up into the feeder canal leading to Banks Lake. The probability that fish would be struck by the pump generating plant's new 9-bladed turbines was also calculated using Monte Carlo simulations. Our measurements showed relatively low turbulence except in the immediate vicinity of the runner environment. The highest pressure experienced by the Sensor Fish was estimated at 157 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 0.755 for 2.36-inch fish to 0.3890 for 11.8-inch fish. The probability of strike estimates indicate that the majority (77%) of kokanne would be carried through the pump without being struck and most likely without injury resulting from pressure and turbulence exposure. Of the 23% that might be struckmore » it is expected that 60% would arrive in Banks Lake without visible external injuries. Thus more than 90% of entrained fish would be expected to arrive in Banks Lake without injury.« less