New turbines are safer for fish

Turbines in the Columbia and Snake River dams are up to 23’ in diameter, and turn at around 70-80 rotations per minute. The flow through a single turbine is equivalent to that of a medium sized river, such as the Deschutes.

There is plenty of room for a 6" fish to pass through, but the route is not without danger. The fish risk being struck or pinched by the turbine blades or other equipment. And once past the blades, turbulence may directly injure or disorient the fish, making them easy prey for predators below the dam.

In the past, juvenile fish were frequently injured by the turbine route. Now, developments in turbine design have made it a safer route of passage. Fish friendly turbines are taking the place of aging turbines on the Snake and Columbia River dams. The diagrams below show the disadvantages of conventional turbines, and the new replacement turbines.