Armed police patrol at the Three Gorges Dam, a gigantic hydropower project on the Yangtze River, in Yichang City, central China's Hubei Province, July 24, 2012. Due to the downpours in the upper reaches of the Yangtze River, China's longest, the Three Gorges Dam experienced its largest flood peak this year on Tuesday, with a peak flow of 70,000 cubic meters of water per second. [Xinhua]