长江是中国最大河流，干流全长6300公里，流域集水总面积180万平方公里，年平均入海量约9600余亿立方米。从干流长度和入海水量论，长江均居世界第三位。

三峡水利枢纽坝址位于长江干流上游的分界处，坝址控制流域面积100万平方公里，多年平均迳流量4510亿立方米，在世界上已建和在建水利枢纽中，与葛洲坝工程同属坝址年迳流量最大的水利枢纽。

-Yangtze is China's largest river, a total length of 6,300 km of the mainstream. Basin catchment area of 1.8 million square kilometers, with the average into the sea is about 9,600 billion cubic meters. Length from the mainstream and into the sea on the Yangtze River has leaped to third place in the world. TGP dam in the upper reaches of the Yangtze River boundaries, control dam basin area of one million square kilometers, average runoff 451 billion cubic meters, the existed in the world of water conservancy hub. the same with the Gezhouba Dam project, the runoff largest water conservancy hub.