Three Gorges Dam site. True colour Landsat satellite image of the Yangtze River in Sandouping, Yichang, China. This valley is now the site of the Three Gorges Dam, the largest hydroelectric power generator in the world. Construction started in December 1994 and was completed in 2006. The Dam is expected to be fully operational by 2011. At its fullest the reservoir covers over 600 square kilometres. Nearly two million people were displaced to make way for the rising water levels behind the dam. Image taken in 1987.