Three Gorges Dam, China. Satellite image showing construction of the Three Gorges Dam, the world's largest ever construction project. The dam (centre, lower left) will harness hydroelectric power from the Yangtze River. Measuring 2.4 kilometres wide and 183 metres high, the dam will create a reservoir covering 632 square kilometres. Its turbines will create 18.2 million kilowatts of electricity. The dam will also help control the problem of flooding, which has killed more than 1 million people over the past 100 years. The dam is scheduled for completion in 2009. Image taken by Ikonos satellite on 16 September 2003.