Diversion dams generate electricity by channeling all or part of a river through a canal or penstock that directs the water past the blades of a turbine to generate electricity. After passing through the turbine blades, the channeled water is used for irrigation or returned to the river.

Pumped storage dams pump water from a lower reservoir to a higher elevation reservoir and then release the water back into the lower reservoir to generate electricity.

Hydropower from dams accounts for 74 percent of the renewable electrical energy in the United States and produces 7 percent of U.S. electricity. The U.S. and Canada are the top hydroelectric generating countries in the world.