China has the most impressive engineering feat of our time, but also one of the most controversial one. The Three Gorges Dam is an engineering marvel, but many point to the project’s environmental and human cost. When construction began in 1994, the project was the largest engineering project in China. By the time it was finished in 2006, it was the world’s largest dam structure.
These days, the project doesn’t even crack the top 20 dam structures, but it remains the largest hydroelectric facility in the world.
The hydroelectric gravity dam spans the Yangtze River by the town of Sandouping and goes downstream of the Three Gorges.
Besides producing electricity, the Dam serves the purpose of increasing the Yangtze River’s shipping capacity. It provides flood storage space and reduces the potential for flood downstream. The Yangtze River has historically been plagued by floods. One, in 1931, caused the death of 4 million people. China regards this project as a monumental social and economical success.
Here are some facts about the Three Gorges Dam.
Composition and Dimensions
Let’s talk about construction first. Made of concrete and steel, the dam is 2,335m or 7,661 fet loon and the top of the dam is 185m (607ft) above sea level.
The project used 27.2 million m3 of concrete. Most of it went for the dam wall. It also used 463,000 tons of steel, which is enough to build 63 Eiffel Towers.
Largest hydroelectric station in the world
We talked about dimensions, but what makes it the largest hydroelectric station in the world is capacity. Since 2012, the Dam is the largest hydroelectric power station and clean energy production base.
The Dam also provides best comprehensive benefits all over the world in water control. The installing generating sets have a combined capacity of 22.5 million kWh, with annual energy output of more than 100 billion kWh. Both rank first in the world.
Electricity produced in the dam is then transferred to Henan, Hubei, Hunan, Jiangxi, Chongqing, Jiangsu, Zhejiang, Shanghai, Anhui, and Guangdong.
Planned for more than 100 years
While the project took more than 10 years to build, it was planned for more than 100 years. The first mention of the dam is in 1918, when Sun Yat-sen, the great leader of China, came up with the idea to build a dam in Three Gorges. He wanted to improve the shipping route and store water resources of Yangtze River.
The first full survey and analysis of the project came in 1955. In 1970, Gezhouba Dam was approved to be build. The Three Gorges Dam draw experience from that dam and in 1992, the new dam was finally approved.
The project officially started in 1994, and completed and started to work in 2009.
Three major purposes
Yes, the Dam attracts more negative attention because of its human and environmental cost. But there are also some positive benefits.
The facility has three main purposes. Those are flood control, hydroelectric power production, and navigation improvement.
And the greatest function is not power production. It is flood control. Its flood control capacity is 22.15 billion cubic meters. Between 27,000 and 33,000 cubic meters flood can be reduced per second.
This can prevent any flood from becoming a devastating disaster.
Cost of the building
The total static investment of the project was $20 billion. But the total investment reached $37 billion, out of which almost $13 million went for project construction, and that much more for the resettlement of more than 1.2 million people in the area.
By 2018, the accumulated income from the facility reached $43 billion, making it a profitable project. A lot of that income comes from tourism.
As we said before, there were critics complaining about human and environmental cost. The Reservoir of the Dam inundated a large area of 79,000 square kilometers (30,502 square miles) in Chongqing and Hubei. It covered the area of 2 cities, 11 country-level towns and 114 small towns. More than 1.2 million people lived in the area.
So, the project had to relocate these citizens for the construction of the dam. Some of them were relocated to neighboring towns or cities, while some went other parts of China.
It slowed the rotation of the Earth
The secret behind this phenomenon is inertia. The Three Gorges is a massive building. And when it is at its maximum, the reservoir holds 42 billion tons of water. A shift in mass that size affects the Earth, increasing the length of a day by 0.06 microseconds.