Severe flood probability on the middle Changjiang (Yangtze River) after completion of the Three Gorges Dam

A major justification for building the Three Gorges Dam on Changjiang is flood control. The dam can reduce peak discharge during severe floods. These floods, however, cannot be prevented by operation of alone. During most floods abnormally high rainfall occurs throughout basin. only affect from upper Large tributaries middle are unaffected dam. cumulative impact large increase severity with distance downstream. Also, Changjiang-lake interaction affected decreasing volume Poyang and Dongting Lakes that occurred past few decades. largest freshwater lakes in China. As a result reduced floodwater storage capacity summer periods, flow into higher base level than previously occurred. Instead back flowing as expected at same time tributary increases river stage.