What is the Three Gorges Dam?

Michael Anissimov
Michael Anissimov

The Three Gorges Dam is the world's largest hydroelectric dam, spanning the Yangtze River in Hubei province, China. It became fully functional on 4 July, 2012, and has the capacity to produce 84.7 billion kw of energy annually. Though it has extremely sophisticated engineering, and is hoped to help China reduce its carbon emissions, its construction and effects have been controversial.

The Three Gorges Dam.
The Three Gorges Dam.


The dam is 7,661 feet (2,335 m) long at the top, with a reservoir of about 410 miles (660 km) long and 3,7000 ft (1.12 km) wide. To put that in perspective, it is about five times the size of the Hoover Dam in the US. The project took 21 million cubic yards (16 million cubic meters) of concrete to build, which set a world record. It has 32 main power generators, which can produce 700 MW each, along with two smaller generators that can produce about 50 MW each. The Three Gorges Dam can produce enough energy to power over 20 million households. Its primary functions are to produce energy and to control flooding.

A ship going through a lock at the Three Gorges Dam.
A ship going through a lock at the Three Gorges Dam.

Positive Effects

When working at full capacity, the Three Gorges Dam can reduce coal consumption by 31 million tons per year, significantly reducing China's carbon emissions and saving hundreds of thousands of lives affected by disease caused by smoke from coal plants. It also serves an important function for flood control. Every few decades, major flooding of the Yangtze occurs, killing thousands, displacing millions, and doing billions of dollars in property damage. The Three Gorges Dam blocks the waters of the river and causes them to be released in a measured fashion, preventing flooding. Additionally, it allows ships of much greater tonnages to navigate the river, which has greatly increased shipping along the river and improved the transportation of goods into the interior of China.

A map of China, where the Three Gorges Dam is.
A map of China, where the Three Gorges Dam is.

Negative Effects

Despite its benefits, the Three Gorges dam has had negative benefits both environmentally and socially. It has greatly reduced the amount of sediment flowing downstream, which is expected to change the ecosystem and lead to less biodiversity. Its location is problematic as well, since it is located on a seismic fault, leading many scientists to predict that it will cause or exacerbate earthquakes. Many landslides have already taken place since construction began, with almost 24 a month happening in the first four months of 2010. In addition, the dam has had serious effects on the plant and animal life surrounding it, contributing to the endangerment of many species. There are fears that the reservoir will become unusable as it becomes filled with pollutants from upstream.

In terms of social effects, millions of people were relocated, sometimes without compensation, to make room for the dam's construction and reservoir. Estimates range from between around 1.5 million to 4 million people being forced to move since construction started. Those who did receive compensation were often given much less than they needed to start a new home, and those who did not were not given an effective means of filing complaints or seeking help.

The Yangtze River, which is a major Chinese waterway, flows from the Three Gorges Dam.
The Yangtze River, which is a major Chinese waterway, flows from the Three Gorges Dam.
Michael Anissimov
Michael Anissimov

Michael is a longtime wiseGEEK 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.

You might also Like

Readers Also Love

Discussion Comments


I honestly think that the Three Gorges Dam was put in to be a moneymaker for the government of China, rather than just a way to save farmers from flooding. While that would have been very altruistic the fact is that the dam has caused massive environmental damage and they are relying on it to be an income generator.

I can imagine though that with the pressure for more energy, and the need to expand their shipping industry, the Three Gorges Dam would have seemed worth every expense.

Can anyone think of a way that the Three Gorges Dam would financially benefit the locals that were displaced?


The Three Gorges Dam has faced a lot of protest from the international community as well as locals. While there are many benefits to the project the rehousing of 1.4 million people to get the project underway caused huge issues, not to mention how the impact of flooding more than 1,000 towns and villages made the locals feel.

The area where the dam is being built also has a lot of issues with pollution now that it didn't have before the structure got underway. Silt, aggressive algae growth and regular pollution that should have been washed away by the river have all caused problems.

I feel that this project was not as well planned as it should have been, especially considering the huge impact it had on the people living there.


it did help a lot. Thanks.


this is so helpful. it helped me to complete this essay i had been working so hard on.


thank you


this has been very helpful. Thanks.


that's great... its construction should be complete soon .thanks pm vohra

Post your comments
Forgot password?