For the civil works mission the commanding general is directed and supervised by the assistant secretary of the army for civil works, also appointed by the President and confirmed by the Senate. Army civil works consists of three congressionally authorized business lines: navigation, flood and storm damage protection, and aquatic ecosystem restoration. Civil works is also tasked with administering the Clean Water Act Section 404 program, recreation, hydropower, and water supply at USACE flood control reservoirs, and environmental infrastructure. The civil works staff oversee construction, operation, and maintenance of dams, canals and flood protection in the U.S., as well as a wide range of public works throughout the world. USACE has 37,000 civilian and military personnel, making it one of the world's largest public engineering, design, and construction management agencies. Some of its dams, reservoirs, and flood control projects also serve as public outdoor recreation facilities. Its hydroelectric projects provide 24% of U.S. hydropower capacity. It is headquartered in Washington, D.C.