"While dams have multiple benefits (balanced against financial and environmental costs), they can also present a risk to public safety and economic infrastructure. This risk stems from two sources: the possibility of a dam failure and the damage it would cause. Although dam failures are infrequent, age, construction deficiencies, inadequate maintenance, and seismic or weather events contribute to the possibility. To reduce the risk, regular inspections are necessary to identify potential problems. Corrective action can then be taken to remedy those deficiencies. Congress is often called upon to fund remedial actions, as a way to prevent the larger catastrophes. The 110th Congress will likely see proposals for improving dam safety and may oversee existing safety programs. To identify deficiencies that could cause dam failures, the federal government established inspection requirements for the nation's federal dams. Once deficiencies are identified, most agencies finance repairs through their operation and maintenance accounts. Funding mechanisms vary for larger rehabilitation activities. At the Bureau of Reclamation, for example, most larger repairs are conducted with annual appropriations to its dam safety program. At some other agencies, dam rehabilitation must compete with other construction projects for funding. The federal agencies with dam safety responsibilities include the Tennessee Valley Authority, the Federal Energy Regulatory Commission (FERC), and the Departments of Agriculture, Defense, Energy, the Interior, Labor, and State. At nonfederal dams, safety is generally a state responsibility, though some federal assistance has been provided."
CRS Report for Congress, RL33108