A $167 Billion Hydropower Megadam Is Underway In China, The World's Largest Of Its Kind By A Long Shot

China has broken ground on what is set to be the largest hydropower dam ever built. In size and output, the megadam will dwarf the current world record holder, the mighty Three Gorges Dam.

The gigantic new structure is being built on the lower reaches of the Yarlung Tsangpo River in the Tibet Autonomous Region of China. Chinese Premier Li Qiang announced the start of the construction on July 19 at a groundbreaking ceremony in Nyingchi City, where part of the hydropower system will run through.

Consisting of five cascade hydropower stations, it’s being built with the capacity to produce a reported 300 billion kilowatt-hours of electricity annually, almost triple the amount generated (111.8 billion kilowatt-hours) by the Three Gorges Dam in central China's Hubei Province, which holds back so much water that it literally changes the rotation of Earth.

Much of this electricity from the Yarlung Tsangpo megadam will be delivered to other parts of China beyond Tibet.

Hydropower plants make use of gravity and the kinetic energy of flowing water to spin turbines, which then drive generators to produce electricity. It’s considered to be a renewable and “clean” energy source that doesn’t produce direct air or water pollution, unlike the burning of fossil fuels.

Reflecting its environmental promise, a Chinese media report from December 2024 described a new hydropower project as “a major move in China's green and low-carbon energy transition.”

“The project is expected to help improve the local eco-environmental monitoring network system, and achieve area-wide protection through its development, thus promoting harmony between humanity and nature,” the article reads.

While China continues to expand its investment in renewables, especially wind and solar, the country still relies heavily on coal and remains the largest emitter of carbon dioxide in the world by a long shot.

Engineering megaprojects like the Yarlung Tsangpo hydropower dam do not come cheap. The project has already received around 1.2 trillion yuan (about $167.8 billion) of financial investment, substantially more than the cost of the Three Gorges Dam.

The announcement of the new hydroelectric dam has also fired up geopolitical tensions. Several of China’s downstream neighbors who depend on the river’s flow have expressed concern about the construction. The Yarlung Tsangpo River flows into northeast India and Bangladesh, where it is known as the Brahmaputra, and both countries have voiced unease over the project’s potential impact on their water security.

Many countries around the world are increasingly wary about water scarcity and the control of water resources. As climate change drives more intense droughts and widespread water shortages, the near future could see the rise of “water conflicts,” in which states and militia groups vie for control over access to critical water supplies.

A study in 2018 examined where such future water conflicts are most likely to occur and identified the Brahmaputra River, along the India-China border, as a potential hotspot.