This study examined the passage of juvenile channel catfish (Ictalurus punctatus) through two propeller-type Restoration Hydro Turbines (RHTs) with different maximum operating speeds. Both trials were conducted with 0.55 m diameter model scale turbines: Trial 1 used a three-bladed turbine operating at 10.0 m of head and 667 rpm (19.2 m/s or 42.9 mph peripheral speed), and Trial 2, shown here, used a two-bladed turbine operating at 9.4 m of head and 980 rpm (28.2 m/s or 63.1 mph peripheral speed).

Groups of 5-26 fish were released into the intake of the turbine and were recaptured after passing through the turbine. Control groups were released downstream of the turbine and recaptured in the same manner.

The combined immediate and 48-hour survival rates for turbine-passed fish were 100% and 98.5% for Trials 1 and 2, respectively, with no significant correlation between observed injuries and turbine passage in either trial. The results of this study indicate that RHT-style turbines could substantially improve downstream connectivity for potamodromous fish species like channel catfish in river systems affected by hydropower. 

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