Sanford Dam, Texas

Most lakes in the nation are manmade, formed by dams, backing up rivers. Lake Meredith, in the eastern Panhandle of Texas, is no exception. It was formed in 1965, when the Sanford Dam was built on the Canadian River. Lake Meredith is a reservoir in an arid area, and one of the primary sources of water for Amarillo and Lubbock, which is connected to the reservoir by a 150-mile long pipeline. Pumping water to the city was stopped in 2011, as drought had shrunk the lake to less than half its peak size.