The massive and controversial Three Gorges Dam on the Yangtze River in China is the largest hydroelectric power plant on earth. It took 40,000 workers to construct it over a 12 year period of time at a projected cost of anywhere between 28 and 88 billion US dollars. The actual cost is unknown. It is the most massive concrete structure on earth. The vision of this giant dam first took root in the mind of Sun Yat-sen in The International Development of China, in 1919. However, the dam's actual construction did not begin until 1994 when it was passed by The National People's Congress.
The Chinese people and government are extremely proud of the dam's success so far and consider it to be a masterpiece of Chinese engineering. It's a beacon of renewable energy and has replaced the burning of 30 million tons of coal each year. The dam is made of a massive amount of concrete of and steel. It's 1.4 miles long and the top of the dam is 607 ft above sea level. The project used 16 million cubic meters of concrete and enough steel to build 63 Eiffel Towers. Its 34 generators, each one weighing 6,000 tons, produce a total energy capacity of 22,500 MW, which is enough electric power for 60 million Chinese people.
[Image Source: Wikipedia]
The Three Gorges Dam also has ship lifts and locks to accommodate the large number of shipping vessels that flow down the Yangtze River. Regular cargo passes through the locks, while passenger ships pass through the ship lifts, which only takes a total of 36 minutes to traverse. Here's what a ship lift looks like to pass through.
But the dam has not been short of critics. The construction of the dam displaced 1.3 million people and destroyed many historical excavation areas. One hundred workers were killed during the building of it. But the huge toll appears to be on the environment, which is beginning to show signs of vulnerability. The truth is, no one knows what kind of long-term impact such a gigantic dam will have on the environment. It appears that fish populations are declining and pollution is building up because the self-cleaning nature of the river has been choked off by the dam.
[Image Source: Wikipedia]
The build-up of pressure on the land where the dam's reservoir sits has caused many landslides, one of which caused another hydroelectric dam in the area to crumble. Also, the water reservoir sits on top of two different fault lines and has been blamed for increased seismic activity. Changing the water levels strains the faults.
Also, sediment, which contains the vital building blocks of life is building up behind the dam and not being sent down river to nourish crops and wildlife. The dam's engineers have devised a way for some of the sediment to pass through the dam, but it's estimated that 30-60% of it still remains trapped behind the dam. This is causing all sorts of problems in the ecosystem.
"The official recognition of the dam's dangers suggests that the project's environmental and public health impacts are starting to sink in. Political analysts speculate that President Hu Jintao and Premier Wen Jiabao are eager to distance themselves from a project they inherited. Although halting plans at this point would be an admission of government error, the openness following the Chongqing meeting raised the hopes of worried scientists that officials would take action to minimize the project's environmental and public health fallout." -Scientific American
Perhaps the most devastating risk lies in the possibility of the dam failing at some point due to seismic activity or some other weakening in the dam itself. Such a flood would be on a scale that has never been recorded. The future will reveal the answer to the question that this article poses.
Written by Leah Stephens