Elephant Butte Dam

Elephant Butte Dam or Elephant Butte Dike is a concrete gravity dam on the Rio Grande near Truth or Consequences, New Mexico. The river was dammed here, impounding the Elephant Butte Reservoir for recreation and agriculture, lessening the downstream flow from a Rio Bravo to a stream a foot deep.

The dam is part of the Rio Grande Project, a project to provide power and irrigation to south-central New Mexico and west Texas. The United States Congress authorized construction of the dam on February 25, 1905 and it began in 1911. It was completed in 1916 but allowed to begin filling in 1915.

Elephant Butte Dam is 301 feet (91.7 m) high, 1,674 feet (510.2 m) long including the spillway and is made from 618,785 cubic yards (473,095 m³) of concrete. The width at the top of the dam is 18 feet (5.5 m) and 228 feet (69.5 m) at the base.

The dam can hold 2,065,010 acre feet (2.54715×109 m3) of water from a drainage of 28,900 square miles (74,850 km²). It provides irrigation to 178,000 acres (720 km²) of land. The dam also contains a 27,945-kilowatt hydroelectric powerplant. The current turbine was installed in 1940 and generates 38,449,061 kWh per year (as of 2005). It is at an elevation of 4390 ft (1338 m).

At the time of its construction, the dam was the largest irrigation dam ever built with the exception of the Aswan Dam in Egypt. It was expected that the dam would become the property of the local settlers once a water tax had reimbursed the government for the cost of construction. During construction the government used a system of 3 cables, each having a capacity of 15 tons and a span of 1,400 feet (430 m).

The name "Elephant Butte" refers to a volcanic core similar to Devils Tower in Wyoming. It is now an island in the lake. The butte was said to have the shape of an elephant.