Three Gorges Dam, dam on the Yangtze River just west of the city of Yichang in Hubei province, China.

When construction of the dam officially began in 1994, it was the largest engineering project in China. At the time of its completion in 2006, it was the largest dam structure in the world.

Submerging large areas of the Qutang, Wu, and Xiling gorges for some 600 km upstream, the dam has created an immense deepwater reservoir allowing oceangoing freighters to navigate 2,250 km inland from Shanghai on the East China Sea to the inland city of Chongqing.

Hydroelectric power production began in 2003 and gradually increased as additional turbine generators came online over the years until 2012, when all of the dam’s 32 turbine generator units were operating.

Those units, along with 2 additional generators, gave the dam the capacity to generate 22,500 megawatts of electricity, making it the most productive hydroelectric dam in the world.

The dam also was intended to protect millions of people from the periodic flooding that plagues the Yangtze basin, although just how effective it has been in this regard has been debated.

The Three Gorges Dam Project has not been without social, economic and environmental controversy though.