Reservoirs include any impounded river system, regardless of size. These systems provide opportunities for recreation, swimming, fishing, power generation, flood control, drinking water, and general enjoyment. As water flows into the impoundment, it characteristically changes, stratifying into multiple layers and reflecting the water quality of the surrounding watershed, shoreline and hydrology. Reservoirs are hybrids of both stream and lake systems. Management of these systems first involves studies of vertical and horizontal profiles of water quality.
Reservoirs metabolize nutrients and contaminants; each portion of the reservoir reflects these processes. Once the processes are understood, various scenarios of management are proposed to reflect the stated goals. Reservoir management encompasses land use throughout the watershed and manipulation of the water body itself.