Possum Kingdom Lake (Brazos River Basin)
Possum Kingdom Lake and Morris Sheppard Dam are located about eighteen miles southeast of Graham mainly in Palo Pinto County, on the Brazos River. The Lake and the dam are owned operated by the Brazos River Authority for municipal, industrial, mining, irrigation, flood-control, recreational, and power-generation uses. The dam, named for Senator John Morris Sheppard, was authorized by the United States Congress in 1935 and by the State of Texas (Permit No. 1262) on May 9, 1938. Construction for the dam began on May 29, 1938, under general contractors C. F. Lytle and A. L. Johnson and was completed on March 20, 1941. Deliberate impoundment started on March 21, 1941 and power generation began on April 17, 1941. The dam, is a reinforced concrete, Ambursen-type, and has a massive buttress with a flat-slab deck, a section of nine roof-weir gates, two bulkhead sections, and an earthen dike. The total length is 2,740 feet with a maximum height of 189 feet with the top of the dam at an elevation of 1,024 feet above mean sea level. The spillway consists of nine roof-weir type gates 73 feet 8 inches wide by 13 feet high with the top of the gate at an elevation of 1,000 feet above mean sea level. Flood control releases are from one or more of these gates having a total discharge capacity of 550,000 cubic feet per second for the nine gates at the design elevation of 1,000 feet above mean sea level. The lake, named after the original place where possum were plentiful for hunters in the earlier day of 1900s, used to have a storage capacity of 724,700 acre feet, and a surface area of 19,800 acres at the conservation pool elevation of 1,000 feet above mean sea level. According to the TWDB 2016 volumetric survey, the storage capacity of the lake has reduced to 538,139 acre feet encompassing a surface area of 17,914 acres at the conservation pool elevation of 999.0 feet above mean sea level (NGVD29). The dam controls a drainage area of about 22,550 square miles, of which 9,240 are noncontributing.