Tajikistan. Nurek. 2009. Nurek dam, the world's tallest dam, seen from an opposite hillside. Tajikistan is among the world's largest hydropower producers per capita. At 300 m (984 ft) it is currently the tallest dam in the world. Construction of the dam began in 1961 and was completed in 1980, when Tajikistan was still a republic within the Soviet Union.