Great Falls on the Potomac River
Great Falls is a portion of the Potomac River near Washington, DC. The river drops 76 feet in less than a mile down a series of cascades and through Mather Gorge
Right below the falls, at the entrance to Mather Gorge is a popular spot for kayakers to practice their craft. They paddle upstream in the calm water on the right, then paddle in to the rapids and try to go upstream, finally coming down through the rapids and paddling over to the calm area again. In this picture you can see one kayaker in the middle of the rapids and two in the calm area on the right waiting for their turn at the white-water.
Above the falls is a small dam that serves to collect and redirect water to the far shore where it is piped to a reservoir and used for DC's drinking water.