Why do people build dams?
Millions of people depend on dams to help provide the right amount of water in the right place at the right time.
Most dams do more than one job! We fish, swim and boat on about 1 in every three lakes formed by dams. Lots of dams provide water for growing crops and for farm animals to drink. They also store water for fighting fires and can help control floods.
Dams also give us hydroelectric power! U.S. dams provide almost 10% of the nation’s power needs. Hydropower is a renewable source of electricity that is friendly to the environment. It does not contribute to global warming, air pollution, acid rain or ozone depletion.