China’s new super-dam carries both geopolitical and environmental risks

The Chinese Communist Party has long thrived on secrecy, and 2024 was no different. As the year was ending, it became clear that Chinese President Xi Jinping’s regime is pressing ahead with a controversial plan that will likely wreak environmental havoc by damming the world’s highest-altitude river as it passes through Earth’s largest canyon.

The dam, the biggest ever conceived, also holds geopolitical risks given its location next to the disputed and heavily militarized China-India border. Indeed, the mammoth dam is being built just before the Himalayan river Yarlung Tsangpo (known downstream as the Brahmaputra) enters India.

Sketchy reports in Chinese state media last month about China’s “approval” of the super-dam’s construction suggest that work is already well underway, given that the project received the go-ahead from the country’s rubber-stamp parliament in March 2021. In fact, Xi’s regime included this dam project in its 2021 five-year economic development plan.

The unparalleled dam, which will cost a staggering $127 billion, highlights the government’s continuing fixation on building the world’s tallest, largest, deepest, longest and highest projects. The new dam will dwarf the biggest dam in the world today, China’s own Three Gorges Dam, whose reservoir is longer than the largest of North America’s Great Lakes.

When completed, the super-dam in southeastern Tibet will generate up to 300 billion kilowatt-hours of electricity yearly — more than triple the 88.2 billion installed capacity of the Three Gorges Dam. Located in central China, the Three Gorges Dam officially uprooted 1.4 million residents to make way for its mammoth reservoir, which submerged two cities, 114 towns and 1,680 villages.

In keeping with its record of secrecy, China has disclosed few details of the super-dam or the number of local Tibetans likely to be displaced, other than to claim that the project would produce “clean” energy. China’s foreign ministry, without saying anything about the dam’s current status, flatly asserted on Dec. 27, “The project will not negatively affect the lower reaches” of the river basin.

In truth, the dam will likely have far-reaching downstream impacts in India and Bangladesh, including altering the cross-border flow and course of the river, which empties into the Bay of Bengal. It will also trap the river’s nutrient-rich silt that helps to naturally fertilize farmlands during the annual monsoonal flooding, as well as sustains marine life.

The dam, in fact, is being built in one of the world’s most species-rich mountainous regions that is known as a biodiversity hotspot. Tibet’s fragile ecosystems are already threatened by climate change and China’s reckless exploitation of the plateau’s vast mineral and water resources. And the super-dam threatens to cause lasting damage to these ecosystems, which play a central role in triggering Asia’s annual monsoons.

To make matters worse, the behemoth dam is in a seismically active area, which raises the specter of a geological disaster. Tibet’s southeastern region is earthquake-prone because it sits on the geological fault line where the Indian Plate and the Eurasian Plate collide. Building the huge dam close to this fault line makes the project potentially a ticking water bomb for downstream communities.

Geopolitically, the megaproject is likely to sharpen the Sino-Indian territorial and border disputes, which date back to China’s 1951 annexation of the then-autonomous Tibet. By occupying the water-rich Tibetan Plateau, where most of Asia’s great river systems originate, China gained significant upstream leverage over multiple neighboring countries to which rivers flow.

Now, the new dam project will give China control over cross-border river flows, thus allowing it to leverage its territorial claim to India’s sprawling, Tibet-bordering Arunachal Pradesh state, which is almost three times the area of Taiwan.

Since 2006, Beijing has been calling Arunachal Pradesh “South Tibet” to assert that it should be part of China. The purported basis of China’s claim to that Indian state, however, has only served to highlight that Tibet remains the core issue in China-India relations.

While maintaining a veil of secrecy over its super-dam project since it was conceived, Beijing has asserted a “legitimate right” to dam the river in a border area. This is in keeping with its longstanding claim that it has “indisputable sovereignty” over waters on its side of the international boundary, including the right to divert as much shared water as it wishes for its legitimate needs.

China is now the world’s most dammed country, with more large dams in operation than the rest of the world combined. China’s dam building has increasingly moved from dam-saturated internal rivers (a number of which are dying) to international rivers.

Over the years, Beijing has kept every major project on an international river under wraps until construction is far enough along that the dam can no longer be hidden from commercially available satellite imagery and the project becomes a fait accompli. In this fashion, China has built 11 giant dams on the Mekong River (and is constructing or planning at least eight more), thereby gaining geopolitical leverage over its Southeast Asian neighbors, but also wreaking serious environmental harms, including recurrent droughts, in the downriver basin.

Against this backdrop, there is growing concern among downstream countries that China is seeking to weaponize the water resources of the Tibetan Plateau, most of whose river systems are transnational in nature. Not content with the 87,000 dams it has, China remains engaged in dam-building frenzy.

Its colossal dam project will not only compel India to prepare for contingencies but also ensure that, despite recent conciliatory moves, mistrust and strategic rivalry continue to define the Sino-Indian relationship. More fundamentally, the project will impose incalculable environmental costs extending from the Himalayas to the delta in Bangladesh.

Brahma Chellaney is a geostrategist and the author of nine books, including the award-winning “Water: Asia’s New Battleground.”