Angostura Dam

Angostura Dam is an embankment dam across the Cheyenne River in Fall River County in southwestern South Dakota in the United States, about 75 miles (121 km) south of Rapid City. The dam consists of an earth-fill embankment with a concrete spillway section, 193 feet (59 m) high and 2,030 feet (620 m) long; it withholds the 195,121-acre-foot (0.240678 km3) Angostura Reservoir. The dam was conceived as early as 1913, but it was not until the 1930s when a regional drought caused crop failures that the project received widespread support from farmers. Built from 1946 to 1949, the dam is part of the Angostura Division of the Pick-Sloan Missouri Basin Program, and is operated by the U.S. Bureau of Reclamation. The dam's primary purpose is to store water for the irrigation of 12,218 acres (4,944 ha) of project lands. The service area lies along 24 miles (39 km) of the Cheyenne River below the dam, and is supplied by the Angostura Canal, which has a diversion capacity of 290 cubic feet per second (8.2 m3/s). The dam and reservoir regulate runoff from an area of 9,034 square miles (23,400 km2). The reservoir has a conservation storage capacity of 138,761 acre-feet (0.171159 km3), with an extra 56,740 acre-feet (0.06999 km3) of surcharge, flood-control storage. Flood water releases are controlled by a spillway with five radial gates, which can pass up to 247,000 cu ft/s (7,000 m3/s). Ango

Dam data from Wikidata (CC0) plus curated additions. Summary from Wikipedia (CC BY-SA).