The Three Gorges Dam in Hubei Province of China (Source: Wikimedia Commons)
The Three Gorges Dam was built in 2003 and it is now considered the biggest hydropower dam in the world. The project started in 1994 when China was looking towards a greener and more efficient way to produce energy to meet the demand of the high increasing population as well as the increase of technology around the country.
This dam was also built with another important purpose. Due to the size of the Yangtze River, the locals were faced with floods, especially in the rain season which affected millions of inhabitants. The dam was built to improve the quality of life for the people within the Hubei Province, but it actually made things worse and also slowed down the rotation of the earth.
How can a dam slow down a planet?
Most people would think at least three times about this whilst scratching their heads and I say this because I did the exact same thing the first time I heard about this phenomenon. When the dam was built it was designed to have state-of-the-art technology such as the latest hydro turbines with high efficiency.
Water released from the Three Gorges Dam in July 2020 (Source: Reuters)
The architecture behind the dam is so good that it can hold 39 trillion kilograms of water (10 trillion gallons of water) with the river rising 175 meters above sea level. With so much water being held up this created an effect called “Moment of Inertia”. Due to the high mass of water being funneled through the dam, Earth loses a bit of momentum when rotating. This moment is mainly created by the huge body of moving water around the planet.
Although this does not affect us that much as from NASA’s calculations the dam only slows the rotation of Earth by 0.06 microseconds. This rotation of Earth is actually slowed down quite often due to other factors such as the moon’s position, earthquakes, and even recently proven climate change.
What is even more interesting is that the rotation of Earth also affected time. Every five years or so the day is made longer by one millisecond so in the future the day could become longer by hours. This even provoked the North Pole to shift by two centimeters.
Was the dam worth it?
At the time this was China’s biggest investment within a project of this size. The dam’s total cost was a bit over $28 billion. Besides the huge price point, due to the high amount of water held back by the dam it created small earthquakes within the west region of China.
In order to keep the people of China safe, 1.3 million people from that region had to be relocated as the earthquakes provoked by the dam were unstable. Besides having people leave their homeland, the construction of the dam also destroyed historical monuments and destroyed the ecosystem of various species of animals which are now in danger of extinction.
In this article from CNN the author makes some prolific arguments about the dam and how it affected the people within the Hubei province before and after it was built.
The dam actually flooded three cities, 114 towns, and 1,680 villages in total. Due to the communist regime within China at the time, those who went out of their way to protest against the dam were killed by the government.
Overall, it seems that the dam caused more harm to the people of China rather than improving their quality of life. Although a marvel piece of engineering we sometimes have to question if in the long run it actually helps humanity.