Hydropower plays a critical role in the U.S. power system, as both source of clean renewable, affordable energy and as a firm, flexible resource that ensures the reliability of the grid. Department of Energy’s Power Marketing Administrations bring the power of water to the public’s front door through a network of high voltage transmission lines. Electricity produced at Federal dams plays a critical role to meeting everyday energy needs of Americans. The dams, owned by the U.S. Army Corps of Engineers, Bureau of Reclamation, International Boundary and Water Commission and Tennessee Valley Authority serve many other important roles. Federal dams have a 42-gigawatt capacity.