Demolition of the last cofferdam protecting the main wall of the Three Gorges Dam, the world's largest water conservation project, was completed successfully on Tuesday afternoon in the middle reaches of the Yangtze River. The removal of the cofferdam means the main wall of the Three Gorges Project has formally begun its role in flood control two years ahead of schedule.
According to a report published on the official website of China Three Gorges Project Corporation, the project contractors, the dam has set the following 10 world records:
1. Most distinct flood control function: The Three Gorges Reservoir has a total storage capacity of 39.3 billion cubic meters, of which 22.15 billion cubic meters is for flood control. The flood-discharging function of the dam can reduce a flood peak by 27,000 to 33,000 cubic meters per second, effectively controlling floods in the upper reaches of the Yangtze River and safeguarding the lives of 15 million people and 2.3 million mu (6 mu=1 acre) of farmland in the lower reaches or Jingjiang area.
2. Largest hydropower plant: The total installed capacity of the Three Gorges Hydropower Plant is 18.2 million kilowatts with an annual electricity output of 84.68 billion kwh.
3. Water conservation construction on the largest scale: The total length of the dam axis is 2,309 meters. The spillway section is 483 meters long. There are 26 turbine generator sets with a per-unit generation capacity of 700,000 kw. The lock is a double-way five-step shiplock.
4. Shiplock with the most steps and highest hoisting distance: The double-way five-step lock has a hoisting distance of 113 meters.
5. Most complicated shiplift: The dimensions of container portion of the shiplift are 120 × 18 × 3.5 m, with a tonnage of 118,000 tons of water and 3,000 tons of other material.
6. Water conservation project involving the most construction: The entire project involved the excavation of 134 million cubic meters of earth-rock for the main structure, and the placement of 27.94 million cubic meters of concrete. 46,300 and 256,500 tons of reinforcement bars and metal structures respectively were installed.
7. Most difficult water conservancy project in 2000: The concrete placement of the project in 2000 was 5.4817 million cubic meters, with monthly maximum placement reaching 550,000 cubic meters.
8. Largest flood discharging capability during period of construction: The damming capacity of the project was 9,010 cubic meters per second, the maximum flood peak discharge measuring 79,000 cubic meters per second.
9. Highest maximum flood-discharge capacity: The spillway has a discharge capacity of 102,500 cubic meters per second.
10. Most complicated resettlement project: As many as 1.13 million people would have been resettled as a result of this project.
(China.org.cn by Wang Qian, June 7, 2006)