As of 2011, conventional hydroelectric plants provide 78,600 megawatts of generating capacity. Pumped storage projects provide an additional 22,000 megawatts of capacity.
Ownership of this hydroelectric generating capacity is divided as follows:
- 50 percent is federally owned;
- 25 percent is privately owned; and
- 25 percent non-federal publicly owned (for example irrigation districts, cities, and water districts).
The Commission has no authority over any federally owned hydroelectric projects. However, it regulates privately and publicly (non-federal) owned projects through a total of 1,022 licenses and 641 exemptions.
FERC-regulated hydroelectric projects are found in all states except for Delaware, Mississippi, North Dakota, and Hawaii. The leading states in hydroelectric power generation are California, Massachusetts, Idaho, Oregon, and Washington.
Many FERC regulated hydroelectric projects are under 100 megawatts. However, the largest privately owned conventional hydroelectric project in the U.S. is the 1,166-megawatt Hellís Canyon project on the Snake River near Adam County, ID and Baker County, OR. The Idaho Power Company has operated the project over 50 years.
The largest operating non-federal, publicly owned conventional hydroelectric plant is the 2,755-megawatt Robert Moses-Niagara project operated by the New York Power Authority at Niagara Falls, New York. The largest conventional hydroelectric project owned by the federal government is the Grand Coulee project on the Columbia River in north central Washington with a capacity of 7,079 megawatts.