After 13 years of preparation and construction, crews poured the final concrete on May 20 for the Three Gorges Dam project, which, upon completion, will
After 13 years of preparation and construction, crews poured the final concrete on May 20 for the Three Gorges Dam project, which, upon completion, will be the world’s largest water conservation project. A brief ceremony was held to commemorate completion of the 1.4-mile-long, 607-ft.-high structure, which required 25.15 million cubic meters (35.51 million yd.) of concrete; 354,000 tons of rebar; and 231,000 sq. meters (276,274 sq. yd.) of leak-proof concrete walls. About two weeks after the ceremony, a crew demolished the last cofferdam holding back the Yangtze River. The blast, which used some 200 tons of explosives, was said to create about 243,000 yd. of concrete rubble.
Dwarfing the U.S. mass concrete standard bearer Û the 10 million-yd. Grand Coulee Dam in eastern Washington state Û the job also required removal of 134 million yd. of stone and earth and filling with 38 million yd. of stone and earthwork. Project costs range anywhere from the official state figure of $22 billion to unofficial estimates of $100 billion.
With construction beginning in 1997, the Three Gorges Dam spans the river in the Hubei province of the People’s Republic of China, making it the largest hydroelectric dam in the world Û five times the size of the Hoover Dam. The completion of the structural work was finished nine months ahead of schedule, according to state officials, although the dam is not expected to become fully operational until 2008 (a year ahead of schedule) after the remaining 12 (of 26) generators are installed. Completed, the dam creates a reservoir 36 miles long and 525 ft. deep and will be able to generate 18.2 million kW of electricity per year, about one-thirtieth of the nation’s current consumption.