The Smith Mountain Pump Storage Project consists of two reservoirs in tandem on the Roanoke and Blackwater Rivers approximately 64 km southeast of Roanoke, Virginia. The reservoirs have provided sites for evaluating the impact of pump storage operation on primary productivity, fisheries, and water quality. Due to the location of the dam and the dendritic nature of the basin, the effect of recycling to alleviate detrimental water quality effects caused by thermal stratification were minimal. Moreover, as might be expected, the quality of water found in the upper reservoir depends upon the quality of water being recycled from the lower impoundment. Recycling appears to enhance primary productivity rates, at least in the vicinity of the dam. Pump storage operation does not appear to detract from the fishery in either reservoir. Although comprehensive studies are still needed in many areas, the results of all studies to date indicate a net beneficial effect of pump storage operation on environmental quality.