one of the world's highest dams, located on the Vakhsh River in Tajikistan near the border with Afghanistan. An earth-fill dam, it was completed in 1980 and rises 984 feet (300 m) and includes an impervious core of concrete reaching 52 feet (16 m) under the river to bedrock. The dam is 2,309 feet (704 m) wide at its crest. The nine-unit power plant associated with the dam has a design capacity of 2,700 megawatts of electricity, and the water impounded is used to irrigate some 1,600,000 acres (650,000 hectares) of farmland.