Waterotor is a low environmental impact technology. Waterotor’s benefit the environment by moderating and smoothing flow rates to reduce erosion and protect shorelines and provide slower moving pools behind each rotor to help fish and other wildlife traveling against the current. Waterotor’s slow rotation speed is fish-friendly. The blades and central drum-like rotor turn in a rolling motion at the river flow speed plus produce a “water cushion” over the rotor to help fish avoid any contact with the rotor. Moreover, Waterotor’s do not produce emissions or require significant civil engineering.