From its source to its estuary, the Yangtze River meanders over 6,300 kilometers. Its annual runoff into the sea amounts to nearly 1,000 billion cubic meters and its total drop is more than 5,800 meters with a hydroelectric power potential of up to 268 million kilowatt.
In order to harness the River and develop its resources, extensive efforts in survey, planning and scientific research have been made since the founding of the People's Republic of China. After overall planning, repeated studies and verifications, the conclusion has been reached that the TGP (Three Gorges Project ) is the key to the comprehensive control of the floods and exploitation of the resources of the River.
The dam site is 27 miles upstream from Yichang City proper, at Sandouping Town, 38km upstream from the Gezhouba Dam Lock, inside the third of the Three Gorges. Designed 2 miles long and 607 feet high, the Three Gorges Project (or Three Gorges Dam), which is the world's largest hydropower project and water conservation project, will hold 36 billion cubic yards of water. A big lake will appear in the Three Gorges, covering 418 square miles and stretches for 373 miles, with annual output of electricity 84.7 kilowatt hours. The whole Three Gorges Project will take 17 years to build since 1993 and is scheduled for completion in year 2009.