Migrant workers on the Three Gorges Dam Project. When finished in 2009 it will be the biggest hydroelectric dam in the world, supplying 11% of China's energy needs. Up to 1.3 million residents will have to leave their homes when they are flooded by the new lake, which will be about 600km long. Wushan, visible here in the valley below, will be flooded in 2003. The new Wushan is being built about 200 metres higher and three times bigger.