Fish Passage Through Turbines: What Do We Know and Where Are We Going

Greater demand for renewable energy has resulted in increasing interest in the development of untapped hydropower resources.  The focus of new hydropower development has primarily been associated with increases in generation at existing projects through equipment upgrades and enhancements or by adding generating facilities to existing non-powered dams.  A key issue that must be addressed at many new and existing hydropower projects is the safe passage of fish migrating downstream.  Although technologies exist to reduce turbine entrainment and bypass fish, employing such measures can often be logistically difficult, expensive, and result in lost power generation.  In recent years, and with funding from the U.S. Department of Energy and industry sources, considerable advancements have been made in the development and application of fish-friendly hydro turbines.  These advancements have included new and unique runner designs, as well as modifications to conventional turbines.  Most of the advancements in fish-friendliness have been based on biocriteria developed from lab and field studies that have investigated the various mechanisms believed to injure fish during turbine passage (e.g., blade strike, grinding, shear and turbulence, and pressure changes).  In addition to fish-friendlier turbine designs, some field studies have demonstrated that fish survival through existing turbines can be high depending on the type of unit and species of interest.  Establishing what is known about fish passage through turbines and where future R&D should be focused will lead to greater protection of fish populations and responsible development of clean energy.  The goal of this symposium will be to present the latest research on injury mechanisms associated with turbine passage, advancements in fish-friendly turbine designs, survival rates for different species and turbine designs, and recent developments in study techniques and methods for monitoring turbine passage and estimating survival rates.