The project is part of an upgrade to a hydroelectric power plant owned by Public Utility District No. 2 of Grant County, and utility officials want to know how fish-friendly the new minimum gap runner turbine is compared to the 40-year-old turbine it replaced. Several Department of Energy Hydropower Program studies seek to answer that and other questions.

"Power company and DOE laboratory biologists are looking at direct mortality to fish caused by injuries during turbine passage, and they're also attempting to assess indirect mortality," said Glenn Cada of ORNL's Environmental Sciences Division. "Even if a fish isn't killed immediately after passing through a turbine, it may become disoriented or physiologically stressed by the experience, and an apparently uninjured fish may fall easy prey to a predator or die later because of the passage stresses."

Indeed, the journey through a turbine isn't easy because fish are subjected to high pressures, shear forces, turbulence and possible mechanical strikes. Still, every year the vast majority of an estimated 2.5 million juvenile Chinook salmon and juvenile steelhead successfully make it through the 10 turbines at Wanapum Dam, located on the Columbia River. Nevertheless, DOE, Grant County officials and resource agencies want to further improve the odds, and they're hoping that this project, one of the largest fish survival studies ever at a single hydroelectric dam, helps.

While the mortality rate of fish passing through conventional hydropower turbines ranges from 5 percent to 15 percent or more, the goal of DOE's hydropower program is to reduce these rates to 2 percent. Advanced turbines are approaching this goal by reducing turb
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Contact: Ron Walli
wallira@ornl.gov
865-576-0226
DOE/Oak Ridge National Laboratory
29-Jun-2005