COLUMBIA RIVER BASIN - DAMS AND SALMON
Adult Fishways at the Dams
Adult fish ladder cut-away graphic
Adult fish ladders at all eight lower Columbia and Snake dams were integrated into the design of the dams beginning with Bonneville in 1938. These ladders consist of a series of steps and pools which provide a gradual upward climb over the dams for returning adults. To steer the adults to the ladders, "attraction" flows at the downstream ladder entrances simulate conditions that would be found at the base of natural waterfalls. The concept has proved effective for adult fish passage.
