The Three Gorges Dam, a man-made structure visible from space, is over 180 meters (over 600 feet) tall and spans more than 2,300 meters (nearly 1.5 miles) across the Yangtze river.
It was finished in 2006 at a cost of nearly 200 billion yuan ($28.6 billion at that time). The government spent almost two decades building it with the promise that it would benefit the Chinese people. While efficacy has frequently been questioned, the dam’s construction affects human life and the environment.
The Three Gorges Dam’s most significant impact on Chinese society was the displacement of millions of people from the Yangtze river region. It’s important because the area around the Yangtze has some of the world’s densest concentrations of people. Despite the difficulty in obtaining precise figures, between 1992 and 2008, more than 1.3 million people who lived in the dam’s floodplain were uprooted and relocated.
156,000 acres with hundreds (perhaps thousands) of towns and villages had to be abandoned and eventually flooded to build the reservoir.
The Chinese government promised villagers compensation for their houses and land value. Some villagers received the whole deal. In some cases, many villagers say they have been paid too little. Or others point out that the dues are reduced through fraud and corruption. Many claim they have only received half the compensation promised for their land.
Additionally, many saw their wages decline, according to researcher Chen Guojie, at the officially backed Chinese Academy of Sciences. The wages of migrant families decreased by 20% after moving.
In addition to lacking material prosperity, many people have been forcibly relocated and have struggled to fit into their new communities. This has led to loneliness, the loss of social networks, a lack of proficiency in the local dialect, and other social and psychological issues.
Some of them decided to return to the Yangtze river region. But they faced many challenges. Their land has submerged, which forces them to relocate northward up the mountain slopes.
Here, steeper slopes and poorer soils reduced land assets and crop yields.
Additionally, many displaced people are currently housed in tents because they lack the funds to restore their homes, which were either damaged during construction or in the wake of a landslide.
Besides affecting people’s lives, the Three Gorges Dam also affects aquatic species
According to the Canadian Journal of Fisheries and Aquatic Sciences, dams separate the natural river continuum into many sections. Therefore dams block migration routes for fish.
The new reservoir transforms the river channel into a lake reservoir, resulting in the loss of vital river habitat for numerous species of river fish.
Nature published a scientific report in 2019 about impacts on fish in the Yangtze River following the construction of the Three Gorges Dam.
It said, “Fish assemblages in three reaches of the upper Yangtze River underwent significant regime shifts during or soon after the dam’s completion and filling of its reservoir.”
The Canadian Journal reported that “Hypolimnetic discharge can lower water temperatures. Retention of sediments in the reservoir can induce a lowered nutrient state and consequently lower primary productivity of downstream waters.”
A study published by Mary Ann Liebert showed that the water flow rate would be man-made to regulate water storage and discharge. Thus, the natural cycle would no longer adjust water flow and temperature.
Fish that live in slow-moving water would be destroyed by the quick discharge of water from the dam because the spawn is being washed away. Many endangered species habitats, including those of the Siberian crane, Yangtze sturgeon, and Yangtze river dolphin, would also be devastated.
The Chinese government planned to build natural reserves and artificial spawning programs to help sustain the Yangtze river dolphin and other endangered species. But previous attempts to move the Yangtze river dolphin have been unsuccessful, and the species is now thought to be extinct in the wild.
Not only was the result of sustaining the Yangtze river dolphin unexpected by the Chinese authorities, but unexpected earthquakes also frequently visited the dam’s vicinity.
In a paper recently published in Geophysical Research Letters, scientists report that the dam sits atop two major fault lines, the Jiuwanxi and the Zigui-Badong. After the dam was built, a lake was created, and the reservoir water played its role in causing earthquakes in the Three Gorges Reservoir Region of China.
John Encarnacion, Ph.D., a geology professor at Saint Louis University, has studied the relationship between earthquakes and dams. He says, “The higher water levels created greater pressure in pore spaces in rocks at lower depths, a known trigger for earthquakes.”
The first disaster came in 2003. A landslide took place when the water level of the reservoir was raised to 135 meters (115 feet).
A few weeks later, a large piece of a mountain broke off and fell into a river on a tributary of the Three Gorges, killing 24 people, damaging around 350 homes, and sinking more than 20 boats.
As the water reached more than 150 meters above sea level, seismic activity in the Three Gorges Reservoir region increased by seven to eight times in terms of average monthly earthquake counts.
Seismic activities continued to take place during 2008 and 2014. And the biggest earthquake struck on December 16, 2013, close to the town of Badong, while two more mild quakes struck in March 2014, close to the town of Zigui.
In September 2014, a landslide destroyed the Lifengyuan Hydropower Station, close to the dam; the event left dozens of people dead. Sichuan Province’s Geology and Mineral Bureau reported over 5,000 danger points, including collapses, landslides, dangerous cliffs, and banks.
A landslide in September 2014 destroyed Lifengyuan Hydropower Station, killing scores of people. This Hydropower Station is close to the Three Gorges Dam. The Geology and Mineral Bureau of Sichuan Province identified over 5,000 risk areas, including collapses, landslides, dangerous cliffs, and banks.
A study from the China Earthquake Administration also reported more than 3,400 earthquakes along the reservoir six years after the reservoir was filled in June 2003. Meanwhile, only 94 earthquakes occurred from 2000 to 2003.
As CNN reported, China’s cabinet admitted, “While the Three Gorges project provides huge comprehensive benefits, there are urgent problems that need to be addressed, such as stabilizing and improving living conditions for relocated people, protecting the environment, and preventing geological disasters.”
The Mandala Projects website cited hydrological expert Dr. Philip B. Williams saying that Chinese officials “have underestimated potential earthquake ground accelerations; they have underplayed the risks of spillway factors as well as risks of major landslides, and they have ignored risks of dam failure downstream and downrange.”