The Gezhouba project is the first large water conservation and hydropower project on China's Yangtze River. It consists of ship locks, power stations, a spillway and scouring sluices, etc. the dam is 2561 meters long and 70 meters high. Locks 1 and 2, each permits the passage of ships of 10000 tons at a time and Lock 3 the passage of passenger-cargo vessels of up to 3000 tons displacement. The power stations have 21 generators with a total capacity of 2.715 million kw and an annual electricity output of 14.1 billion kwh. if the 27 gates of the spillway and the 12 gates of the scouring sluices are fully opened, their maximum discharge capacity amounts to 11000 cubic meters per second.