Tapping the power of the mighty Yangtze River has been a long-held dream of many Chinese leaders, including Sun Yat-sen and Mao Zedong. When fully operational, the Three Gorges Dam's 26 turbo-generators can produce 84.7 billion kwh of electricity annually, or roughly enough power for the whole of Shanghai. By the time six more turbines are added by 2012, the dam can generate 104.2 billion kwh of electricity a year. This massive supply of clean energy will go a long way towards helping China reduce its reliance on polluting coal as its main source of power, the government argues. Chinese officials estimate that the mega-dam has thus far helped the country reduce the amount of greenhouse gas emission by 191.3 million tonnes.

But the decision to build the Three Gorges Dam has not been an unanimous one despite the promise of clean, almost unlimited power. When the project was put to a vote in 1992, a third of the 2,600 Chinese lawmakers present did not give it a "yes" vote in an unprecedented show of dissent. Professor Lei Hengshun of Chongqing University, who was among those who abstained during the vote, said he did not give his support as he was not convinced that enough had been done to assess the full impact of the mega-dam. The issue remains far from clear-cut, the academic says, even after two decades of his own research. [Above: Zigui, Oct 2006. Below: The dam as seen in June 2003 and Nov 2007.]