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What is the World's Largest Dam?

Michael Anissimov
Michael Anissimov
Michael Anissimov
Michael Anissimov

The world's largest dam is the Three Gorges Dam on the Yangtze River in China. Structural work was completed in 2006. The dam is 2,309 m (1.4 mi) long and 185m 607 ft) tall, six times the size of the Hoover Dam. When its generators are installed and it goes online in early 2009, it will be the world's biggest power plant. The Three Gorges Dam will generate 18.2 GW, or about 2% of China's total power consumption. China's exploding economy needs power, and considerable effort has been placed towards alternative forms of energy which do not pollute the air, as China's primary source of energy is coal.

The Three Gorges Dam has been at the center of controversy since its construction was announced. Over 1,000,000 people had to be evacuated to avoid the flood basin it created, which is 660k m (410 mi) long and submerges 632 sq km of land. 1,200 towns and villages were relocated in preparation for its construction. Following an incident in 1975 during Super Typhoon Nina where 140,000 people were killed due to catastrophic dam failure, extra precautions were taken in the engineering and fault tolerance of the Three Gorges Dam. It will be guarded by large amounts of soldiers around the clock to deter possible terrorist attacks.

A map of the world.
A map of the world.

Despite frequent criticisms stating that the costs of the Three Gorges Dam could be as high as $100 billion US Dollars (USD), the actual cost is not likely to exceed $22.5 billion USD. Most of this is being paid for by a national tax on electricity. Officials have stated that the dam will pay for itself with power generation.

Part of the role of the dam is also to engage in flood control. It will decrease the number of major downstream floods from once every 10 years to once every 100 years. Its massive 22 cubic kilometer reservoir will regulate the flow of water, increasing during the big floods and releasing the water at a uniform rate, sparing people downstream from the devastating economic effects of floods. The Three Gorges Dam's reservoir will be 200 m (219 yards) deep when it is fully flooded.

Michael Anissimov
Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Michael Anissimov
Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

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Discussion Comments

Feryll

There was this group of beavers that would build dams in the waterway near my house when I was growing up. Watching them at work was unbelievable. My friends and I would go fishing and we would spend more time watching the animals cutting down and moving trees than we spent fishing.

From time to time the county workers would tear down the dam, and the beavers would build it back in short time.

Sporkasia

Most of know the benefits of dams. They are one of the best ways we have for producing electricity. And this type of electricity production is more environmentally friendly than something like burning coal, or so you would think.

What many people do not know is that dams can lead to flooding, which is responsible for unbelievable amounts of property damage. People are left homeless and crops are destroyed by flood waters. And of course, more importantly, people lose their lives in floods.

Dams also lead to more erosion and to the destruction of wildlife habitats that depend on the smooth flow of the water being blocked by the dams. You might be surprised to learn that when you add it all up, there are more negatives associated with dam construction than positives.

Drentel

I have been to the Hoover Dam and I can't imagine any dam being larger than that one. I went there with my family when I was a kid. We were going to see the Grand Canyon and my father thought we should see the dam while we were so close. I had never seen so much water in one place. It was amazing. It seems impossible that Three Gorges Dam in China could be six times the size of the Hoover Dam.

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    • A map of the world.
      By: Kheng Guan Toh
      A map of the world.
    • A map of China, where the world's largest dam is located.
      By: pavalena
      A map of China, where the world's largest dam is located.
    • A ship going through a lock at the Three Gorges Dam, the world's largest hydroelectric dam.
      By: Harvey Barrison
      A ship going through a lock at the Three Gorges Dam, the world's largest hydroelectric dam.
    • The Three Gorges Dam, which spans the Yangtze River in Hubei province, China.
      By: Harvey Barrison
      The Three Gorges Dam, which spans the Yangtze River in Hubei province, China.
    • Though now surpassed by the Three Gorges Dam, the Hoover Dam was the world's largest concrete structure when it was completed in 1935.
      By: William Warby
      Though now surpassed by the Three Gorges Dam, the Hoover Dam was the world's largest concrete structure when it was completed in 1935.