Grade: B.    Reason: thin, but OK
Image of a map of the contiguous 48 states, showing the top 5 hydropower producing states in 2007. number 1 was Washington, number 2 - Oregon, number 3 - California, number 4 - New York, number 5- Montana
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Data for this map

Most U.S. Hydropower Is in the West

Over half of U.S. hydroelectric capacity for electricity generation is concentrated in three States: Washington, California, and Oregon. Approximately 31% of the total U.S. hydropower is generated in Washington, the location of the Nation's largest hydroelectric facility — the Grand Coulee Dam.

Most hydropower is produced at large facilities built by the Federal Government, such as the Grand Coulee Dam. The West has most of the largest dams, but there are numerous smaller facilities operating around the country.

Most Dams Were Not Built for Power

Only a small percentage of all dams in the United States produce electricity. Most dams were constructed solely to provide irrigation and flood control.