China is constructing an unprecedented system of large dams along its longest river. This is part of a series of hydroelectric power projects being developed in one of the planet’s most remote and harshest regions.
The rivers involved in this dam construction project originate from high mountains in Tibet, providing water for one-fifth of the world’s population. Among them is the Yangtze River, which plays a crucial role in China’s economic goals. The Chinese government is pushing forward with projects to build over 10 dams along this section of the river.
Ruth Gamble, an environmental historian specializing in Asia from La Trobe University, commented on the construction activities in this area: “These large projects are being undertaken in one of the most earthquake-prone places on Earth.”
Just the construction of the Baihetan Dam required over 10,000 workers, around 8 million m3 of concrete, and “cost” $31 billion. This dam has a maximum height of 289 meters and a curved length of 709 meters, generating 16,000 megawatts of electricity—double the output of the largest dam in the United States, the Grand Coulee Dam. However, this is just one of the dams being built along the Yangtze River.
Baihetan Dam.
China estimates that the upstream sections of the Yangtze River, known as Jinsha River, located between the Tibet Autonomous Region and Sichuan Province, have the potential to generate 112 gigawatts of electricity. This figure accounts for one-quarter of the current total hydroelectric capacity of the country.
Gamble noted: “Many people say that China is the hydroelectric center of the world, and the southwest region is the hydroelectric center of China. The country is striving to achieve net-zero emissions, and constructing hydroelectric projects helps them reach that goal faster. This area has the largest concentrated hydroelectric potential in the world.”
The rivers originating in Tibet quickly flow down to the lowlands, allowing kinetic energy to be harnessed as hydroelectric power. However, Gamble points out that this area, while abundant in hydroelectric potential, is also geologically unstable. Therefore, construction carries significant risks.
A section of the Jinsha River in Sichuan Province.
The dams on the Jinsha River are very susceptible to strong impacts due to the tectonic plates that frequently shift in this area, along with numerous fault lines in the vicinity. The largest dam on this river will stand 239 meters tall, making it the tallest rockfill hydroelectric dam in the world, part of the Lawa hydropower plant project, and is expected to cost $4.6 billion.
This project is particularly challenging to complete as it is being constructed in the riverbed. To build it, the team needs to stabilize the terrain by pouring rocks and concrete mixtures onto the riverbed—where it is “soft as jelly.” Meanwhile, massive concrete walls will be placed along the mountain edges to withstand landslides and avalanches.
Construction site of the Lawa hydropower plant on Google Earth.
Ms. Gamble explains that this 239-meter high dam is constructed in multiple layers of concrete, with each layer being the size of a high-rise building, “sitting” next to the concrete-clad cliffs. Furthermore, the dams are being constructed on unstable ground, surrounded by steep mountain slopes in one of the most earthquake-prone areas of Asia.
In just 2007, over 100 earthquakes occurred between the Sichuan basin and the Jinsha River. Then, in 2008, a major earthquake struck Wenchuan in the Sichuan basin. This was one of the largest earthquakes China has ever experienced, killing more than 87,000 people. Therefore, if an earthquake occurs affecting the fault lines along the Jinsha River, all dams on the river could be destroyed.
Gamble explains, “If a major earthquake causes a failure in one of these dams, it will be like a domino effect. If they cannot maintain two dams, then with each failure, the disaster will worsen.”
