Lake Gonzales, also known as H-4 Reservoir and as Guadalupe Reservoir H-4, is on the Guadalupe River four miles southeast of Belmont in western Gonzales County (at 29°30' N, 97°37' W). The project, in the Guadalupe River basin, is owned and operated by the Guadalupe-Blanco River Authority for the generation of hydroelectric power. The authority purchased this and five other projects on the Guadalupe River by a contract that became effective on May 1, 1963. Dam construction for the reservoir was started in 1929 and completed in 1931, when water impoundment and power generation began. In the 1980s the reservoir had a capacity of 5,200 acre-feet and a surface area of 696 acres at an elevation of 332 feet above mean sea level. The reservoir is maintained at a practically constant level, except during floods, by regulation of the power output to the water inflow. This project's hydroelectric power plant is part of the dam structure. The power plant, which consists of one generating unit with all auxiliaries, has a generating capacity of 2,400 kilowatts. The river flow has been partly regulated since June 1964 by releases from Canyon Lake. The drainage area above the dam is 2,038 square miles.