The Development of Advanced Hydroelectric Turbines to Improve Fish Passage Survival

Abstract

Recent efforts to improve the survival of hydroelectric turbine-passed juvenile fish have explored modifications to both operation and design of the turbines. Much of this research is being carried out by power producers in the Columbia River basin (U.S. Army Corps of Engineers and the public utility districts), while the development of low-impact turbines is being pursued on a national scale by the U.S. Department of Energy. Fisheries managers are involved in all aspects of these efforts. Advanced versions of conventional Kaplan turbines are being installed and tested in the Columbia River basin, and a pilot scale version of a novel turbine concept is undergoing laboratory testing. Field studies in the last few years have shown that improvements in the design of conventional turbines have increased the survival of juvenile fish. There is still much to be learned about the causes and extent of injuries in the turbine system (including the draft tube and tailrace), as well as the significance of indirect mortality and the effects of turbine passage on adult fish. However, improvements in turbine design and operation, as well as new field, laboratory, and modeling techniques to assess turbine-passage survival, are contributing toward resolution of the downstream fish passage issue at hydroelectric power plants.