How big can a fish be and still pass through the Restoration Hydro Turbine (RHT) safely? Pretty big! This passage test of 186 rainbow trout measuring up to 500 mm (~19.7 in) in length found no meaningful difference between the fish passed through a 1.9 m (~ 6.2 ft) diameter RHT and the control group, who were not passed through any turbine.
This fish passage test was conducted jointly by Natel Energy and Pacific Northwest National Laboratory (@PNNL) in the spring of 2022, at Natel's Monroe hydropower plant in Culver, Oregon.
For more info about Natel's fish passage testing and peer-reviewed papers, visit our fish passage page.