The river water impounded by the dam forms the long Conowingo Reservoir, known locally as Conowingo Lake. The reservoir is used as a drinking water supply for Baltimore and the Chester Water Authority; as cooling water for the Peach Bottom Nuclear Generating Station; and for recreational boating and fishing. In low rainfall or drought conditions, balancing the desire to maintain the reservoir level with the water flow needs for the downstream ecology is one of the challenges faced by the dam operators.