Nurek Dam is the world’s tallest dams. It is located on the Vakhsh River in the central Asian nation of Tajikistan, near the border with Afghanistan. It is an earth-fill embankment dam. The primary purpose of the dam is hydroelectric power generation and the power station's first generator was commissioned in 1972 while construction of the dam began in 1961. Nurek dam is the second tallest man-made dam in the world.
Dimension: The reservoir formed by the Nurek dam is simply known as Nurek and is the largest reservoir in Tajikistan with a capacity of 10.5 km3. The total height of the dam is 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 hydroelectric plant located within the dam is fueled by the reservoir. Water stored in the reservoir is also used for irrigation of local agricultural land. Dangara irrigation tunnel is used to transport irrigation water for 14 kilometers. This water is used to irrigate about 700 km2 of farmland.
Construction: The Nurek Dam was constructed by the Soviet Union between 1961 and 1980. It was the period when Tajikistan was still considered a part of the republic of the Soviet Union. It is uniquely constructed. It has a central core of cement forming an impermeable barrier within a 300m (980 ft)-high rock and earth fill construction. Inclusive in the dam are nine hydroelectric generating units out of which the final generating unit was commissioned in 1979. Because of the abundance of material on-site, the Nurek Dam was constructed using materials found locally, making the construction considerably less expensive than the alternative types of dams built using other materials. The construction phase involved preparing the materials to be used in the dam’s construction, compacting them, and preparing layers onto which they would be poured and settled. Although the majority of the dam is a rock- and earthfill dam constructed with locally found materials, an impermeable barrier was built out of cement to separate the central core from the 984-foot (300-m) dam. An estimated 5,000 people were resettled from the dam's flooding area.
Electricity: A total of nine hydroelectric Francis turbines are installed in the Nurek Dam. They have since been redesigned and retrofitted such that they now combine to produce 3.0 gigawatts after having an initial generating capacity of 300 megawatts each (2.7 gigawatts total). As of 1994, this formed most of the nation's 4.0 gigawatt hydroelectric generating capacity. 4.0 gigawatts of energy is adequate to meet 98% of the nation's electricity needs.