Three Gorges Dam is the world’s largest dam. It is designed to control flooding and improve navigation on the Yangtze River, China’s longest river. The dam also generates hydroelectric power. The dam is just west of Yichang, in Hubei Province. Construction began in 1994. In 2006, work on the dam wall was completed.
Three Gorges Dam is about 11/3 miles (2.1 kilometers) long and 610 feet (186 meters) high. The dam’s reservoir extends upstream nearly 400 miles (645 kilometers). It holds more than 31 million acre-feet (38 billion cubic meters) of water. Scientists have calculated that the shift of such a mass of water will slow the Earth’s rotation and will increase the length of a day by 0.06 microseconds. The water covers about 150,000 acres (60,700 hectares) of land, including many towns and villages and several archaeological sites. About 11/3 million people had to be resettled.
The project has stirred much controversy. Supporters say the dam will save lives by preventing floods on the eastern Yangtze. It will also bring development to the areas along the western Yangtze. They point out that the electric power the project generates will help reduce the use of coal and decrease air pollution. But critics are concerned about the dam’s environmental impact. They regret the loss of cultural relics and historic sites. They also worry about the effect of forced relocation on large numbers of people.
The dam’s boat locks were opened to shipping traffic in 2003. Later that year, the dam’s first working generators began producing commercial electric power. The last of the dam’s 32 generators went into operation in 2012.
See also Hubei Province ; Yangtze River.
