After the USACE construction was complete on the dam, the lake began filling in 1969. The dam rises above the Sac River streambed. The lake is about with of shoreline. Normal pool is at 867 feet above mean sea level (msl) with storage of . The flood storage capacity of the lake is of water at an elevation of 892 ft msl, during which the surface area of the reservoir grows to . Stockton Lake is operated primarily for flood control and hydroelectric generation and originally had an installed capacity of 45.2 MW in a single electric generator.