YICHANG, Hubei, Sept. 20 -- The largest flood peak on the Yangtze River this year smoothly passed the Three Gorges Dam Saturday afternoon.

Water flow reached 55,000 cubic meters per second at about 8 a.m. after heavy downpours hit the upper reaches of Yangtze, where the dam is located, said Xiao Ge, an official at the dam's communication center.

It gradually receded to 52,500 cubic meters per second at 2 p.m. as the flood peak passed.

The operation of the generators, the condition of the dam and the buildings are all normal, said Xiao.

The dam's ship lock has been closed since Friday and wil not resume until the water falls to a safe level, the dam's operators said.

The world's largest water hydropower project, the Three Gorges Damn has a five-tier ship lock and a total of 32 hydropower turbo-generators.

The project generates electricity, controls flooding and adjusts shipping capacity on the river. Built to tame annual Yangtze floods and generate power, the dam is capable of holding 22 billion cubic meters of water.