Hydropower uses the energy of flowing water to produce electricity. It is a valuable renewable energy source because it minimizes air pollution and provides a consistent power source to help meet minimum energy demands, also known as base load. However, it does have some downsides. It disrupts the fluvial ecosystem. It is vulnerable to reductions in electrical generation in low water seasons or drought years, and has high initial capital costs. Most hydropower in the United States is produced through dams or impoundments used to store and divert water into turbines to produce electricity. In 2011, hydropower, nationwide, accounted for 9% of U.S. power production, and was the largest contributor to renewable electric power generation followed by wind, wood, and wood-derived fuels. The top hydropower-producing states in 2011 were Washington, Oregon, and California.
Ownership of hydropower generation facilities is classified as "federal" or "nonfederal". The majority of federal projects are owned and managed by the Bureau of Reclamation or the U. S. Army Corp of Engineers and are principally large multi-purpose dams capable of producing more than 30 megawatts (MW) of electricity. Nonfederal projects can be privately owned, or publically owned, and located on public, or private land. Nonfederal projects are licensed and administered by the Federal Energy Regulatory Commission (FERC) and are principally categorized as small hydropower (1-30 MW). In 2010 nonfederal hydropower accounted for 4% of total U.S. electrical power generation. It appears that all hydropower plants on BLM managed land are considered "nonfederal" projects and consequently are regulated by FERC.
For more information, go to Hydropower in OR/WA (PDF)