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.
A new study published in the North American Journal of Fisheries Management shows safe downstream passage of juvenile alewife (river herring) through Natel’s modern FishSafe hydro turbine.
Abe Schneider and Sterling Watson lay out the argument for FishSafe™ turbines in this paper published in The International Journal of Hydropower & Dams, Issue 5.