The spillway for the Hoover Dam is at the south end of the Hoover Reservoir.

Hoover Reservoir consists of 5,026 total acres. This is made up of 3,843 Water acres at normal water levels and 1,183 Land acres that include The Hoover Nature Preserve that is just over 925 acres. There are areas of open water, wetland swamp, wetland forest, riparian corridors, deciduous forest, pine stands, prairie remnants, and seasonal mudflats. The main roads around Hoover Reservoir are Sunbury Road, Big Walnut Road, Tussic Street, and South Old 3C Highway on the West; Sunbury Road on the North; Sunbury Road, Red Bank Road and Schott Road on the East; and Central College Road on the South. Smothers Road crosses the reservoir along the Franklin-Delaware County line.