Iran state radio said the dam would cost $2 billion and that China would finance the entire cost with a credit line.
The firm building the dam is Sinohydro Corp., described as the world’s largest hydroelectric company.
The Bakhtiari Dam will be a concrete arch dam on the Bakhtiari River that forms the border between Lorestan and Khuzestan provinces in the southwest.
The reservoir behind the dam is to be the second largest in the country after the Karkheh Dam reservoir.
The dam will generate 1,500 megawatts of electricity or 50 percent more than the Bushehr nuclear power plant is designed to generate.
The dam will be 315 meters (1,033 feet) high. That will make it the tallest dam of any kind in the world, surpassing the 300-meter earthen Nurek Dam in Tajikistan and the 285-meter concrete Grande Dixence Dam in Switzerland.
Iran did not explain why it was hiring a foreign firm to build the dam. Iran has already built about 580 dams and prides itself on being a master of the technology. And several of Iran’s dams are quite large. The tallest is the 230-meter Karun-4 Dam on the Karun River.