Three Gorges Dam dam. An important function of the dam is to control flooding, which is a major problem for the seasonal river of the Yangtze. Millions of people live downstream of the dam, with many large, important cities like Wuhan, Nanjing, and Shanghai situated adjacent to the river. Plenty of farm land and China's most important industrial area are built beside the river. The reservoir's flood storage capacity is . This capacity will reduce the frequency of major downstream flooding from once every ten years to once every 100 years. The dam is expected to minimize the effect of even a "super"
Three Gorges Dam Two short rail lines, one on each side of the river, are to be constructed. The 88 kilometer long northern portage railway (北岸翻坝铁路) will run from the Taipingxi port facility (太平溪港) on the northern side of the Yangtze, just upstream from the dam, via Yichang East Railway Station to the Baiyang Tianjiahe port facility in Baiyang Town (), below Yichang. The 95 kilometer long southern portage railway (南岸翻坝铁路) will run from Maoping (upstream of the dam) via Yichang South Railway Station to Zhicheng (on the Jiaozuo–Liuzhou Railway). In late 2012, preliminary work started along both future railway routes. Though the