YICHANG, China—According to legend, one of China's ancient emperors—Da Yu, or Yu the Great—changed the course of Chinese history by placing a mountain in front of the Yangtze River, forcing it to flow east through the Middle Kingdom (instead of south like the other great rivers that rise in the same Yunnan region of southwest China). Not to be outdone, the modern Chinese government has undertaken a massive project to control the flow of this ancient waterway, erecting Three Gorges, the world's largest dam, to block it.

View Slide Show of Yangtze River Development

That megaproject, completed in 2006 at a cost of $30 billion (180 billion yuan), has already raised the water level in the upper reaches of the river by as much as 66 feet (20 meters), stretching all the way to the city of Chongqing. As a result, the ubiquitous barges plying the river no longer need human muscle to beat the flow and can carry more than three times as much weight—from 3,000 tons per ship to 10,000 tons of coal, cars and other goods.

The dam also provides 22,500 megawatts of power, without emitting the greenhouse gases and other air pollutants produced by coal-fired power plants that provide more than 75 percent of China's electricity.  In addition, the massive dam generates more power than 18 1000 megawatt nuclear reactors as well as protects communities downstream from horrific floods—such as one in 1998, which left 14 million homeless—that once plagued Wuhan, Nanjing and even Shanghai.

"One of the main reasons to build Three Gorges dam [was] to store water in the upper river so as to protect eastern parts of the country," says Lai Hun Suen, a professor of sustainable development at Chongqing University and a municipal government official.

But it came at a cost: More than four million residents of towns, villages and cities in the path of the rising waters were forced to relocate, most of them to bustling Chongqing. What's more, when the water level changes it unleashes a miasma of disease from exposed sewage. The baiji dolphin has also been rendered extinct by a combination of overfishing and habitat destruction caused by human activity.

Environmental challenges could undermine the world's largest dam as well. Silt could gum up the Three Gorges and climate change could completely transform the water supply as the glaciers dwindle atop the Tibetan Plateau, among other issues.  And efforts to emulate Da Yu—smaller dams have proliferated in the upper reaches of the river—may yet prove the undoing of the mightiest of man-made waterworks. "We have taken big floods into consideration," Lai says, "what we did not expect is less water."

View Slide Show of Yangtze River Development

2 Comments

1. 1. David M. Clemen 03:51 PM 8/22/08

   As stated in the article, one of the main reasons to build the Three Gorges dam was to establish a "flood control" structure because over 300,000 people have died in Yangtze River floods in the 20th century(156,000 in 1840; 142,000 in 1935; over 33,000 in 1954; and most recently over 3,000 in 1998). The electrical power generation and navigation enhancements are ancillary benefits that will economically revive the region because they supply cheap power, and a means for the farmers to export their crop to the other parts of China.
   Naturally, when you build a large dam with its associated large reservoir, there will be ecological problems that were not previously existent; and these must be handled. However, the logic dictates that you must build the dam to save the thousands of human lives; and eliminate the constant flooding which maintained the geographical area in a poverty status. Once the dam is built, you must address the ecological problems that were unforeseen prior to the construction of the dam.
   Hydro power is a renewable source of energy (It rains, the water runs downhill thru a turbine producing electricity, it exits the plant as water, evaporation occurs, it rains, etc. etc.) with "zero" emissions. As stated, this is a great advantage over several more coal fired plants with their associated Greenhouse Gas Emissions.
   In summary, the dam was required to avoid the loss of human life due to the frequent flooding of the Yangtze River; and the saving of human lives on such a large scale is imperative. The ecological problems created, that were not foreseen, have to be addressed. The electrical power generation and increased navigation capability is an additional ancillary benefit

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2. 2. Uncle B 03:06 PM 11/12/09

   Astounding! If the Chinese develop Solar possibilities of their enormous desert regions, and make use of Wind Power too, as well as re-generating sewage to bio gasses, fertilizers from large cities, they will stand head an shoulders above the Americans, wasteful and expensive to maintain, as they are! beware! China can pull the "population control" plug at any time and overwhelm the world with people power! They have already bred an intelligentsia elite, quite deliberately, are well aware of DNA, and not restricted by religious beliefs or corporate interests, as Stem Cell research has illustrated! A new world order to be born in China? A Super-Race? vegans? Low maintenance, high intelligence units? Smaller in size, manning lighter, faster, planes, cars, industries factories, schools, colleges, Universities? Totally in Mandarin? Are we witnessing the end of the great hulking American Neanderthal evolved these past 200 years, now facing an unbeatable opponent with a deflated dollar still falling like a stone? Has his economy collapsed? Are his industries, factories, migrated to Asia? Is he failing at sustainability as we speak? Is this the "Fourth Turning" for America? Fear This?
   

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