Cahora Bassa Dam, dam on the Zambezi River in Mozambique. The dam, 303 m (995 ft) wide at the crest and 171 m (560 ft) high, impounds Lake Cahora Bassa, which is about 240 km (about 150 mi) long. With an installed capacity of 2,075,000 kilowatts and a planned capacity of 4 million kilowatts, it is one of Africa’s largest hydroelectric projects.

The Cahora Bassa Dam was planned and built by the Portuguese government, which ruled Mozambique from 1498 to 1975; construction began in 1969. It was originally called Cabora Bassa Dam. Portugal hoped that constructing the dam would allow it to perpetuate its rule in Mozambique by providing both hydroelectricity for local industrial development and for export to South Africa, and water for a proposed irrigation project. The project was strongly opposed by the Front for the Liberation of Mozambique (Frelimo). The dam was completed in 1974. Mozambique became independent in 1975, and Frelimo came to power.

Exports of hydroelectricity to South Africa began in 1977. The new government’s plans to use Cahora Bassa Dam to stimulate national development were frustrated by continued political upheaval and violence, some of which was directed at the project. By 1983 widespread sabotage of transmission lines had effectively cut off the supply of hydroelectricity for both domestic use and export. The civil war was formally ended in 1992; rehabilitation of the 900-km (560-mi) transmission line to South Africa began in 1993, and exporting of power resumed in 1998. By agreement, ownership of Cahora Bassa Dam was transferred gradually from Portugal to Mozambique; Mozambique assumed full control in 2007.