"Dams provide drinking water, hydroelectric or water power, flood control, recreation, and many other benefits to people and local economies. But if they fail, dams can pose significant risks to people and property downstream. There are dams in every State. It is important to know if you and your loved ones live, work, or play in areas that may be affected by a dam and what to do if one fails. This booklet was created to help answer questions about dams: what purposes they serve, what risks are associated with dams, and where you can get information about how to react if you are affected by a dam."
United States. Federal Emergency Management Agency: http://www.fema.gov/