The largest dam ever conceived symbolizes China’s bid, from oil to water, for 21st-century dominance

Brahma Chellaney

Nikkei Asia

China is about to upend the world’s hydrological balance — with consequences as far-reaching as climate change itself.

Its $168 billion Himalayan super-dam represents not merely the world’s costliest infrastructure project but also one of its riskiest. What Beijing portrays as an engineering marvel is in fact an ecological disaster in the making.

The dam is being constructed on the Yarlung Zangbo River (also known as the Brahmaputra), just before it curves into India. The project’s significance was underscored by the fact that Chinese Premier Li Qiang, flanked by senior officials and leaders of major state-owned enterprises, formally announced the groundbreaking in July, although satellite imagery had indicated activity at the site for some time.

The last time a Chinese leader inaugurated a dam project was 1994, when then-Premier Li Peng presided over the groundbreaking ceremony for the Three Gorges Dam on the Yangtze River. That symbolic parallel underscores the magnitude of the Brahmaputra mega-dam — an undertaking that will surpass the Three Gorges in scale, ambition and peril.

The Three Gorges Dam was initially celebrated as a modern wonder but is now widely recognized as an environmental and social disaster: It displaced more than a million people, triggered recurrent landslides, degraded water quality and disturbed seismic stability. Its mammoth reservoir has even slightly slowed the Earth’s rotation.

China’s new megaproject is in an even more fragile setting: one of the world’s most seismically active zones, straddling a heavily militarized frontier where Beijing claims India’s sprawling Arunachal Pradesh state as “South Tibet.” Constructing the world’s largest dam atop a geological fault line is more than reckless — it is a calculated gamble with catastrophic potential. Any collapse, whether from structural weakness or reservoir-induced seismicity, would devastate India’s northeast and Bangladesh, placing tens of millions at risk.

The dam, designed to generate nearly three times the electricity of the Three Gorges Dam, was approved by the National People’s Congress in March 2021. Yet the project remained cloaked in secrecy until the recent announcement, true to Beijing’s pattern of concealing work on major dams along international rivers until commercially available satellite imagery makes it impossible to hide.

The Brahmaputra, unlike most rivers, is an ecological lifeline, sustaining one of the world’s most biodiverse regions as it descends sharply from Himalayan heights to form the longest and steepest canyon on Earth — twice as deep as America’s Grand Canyon. It is here that China is constructing the behemoth dam to tap the unparalleled concentration of river energy.

Originating in Tibet’s mountain springs, the world’s highest-altitude major river flows through India and Bangladesh, supporting agriculture, fisheries and dense populations. Its annual floods, while destructive, flush toxins, recharge groundwater and deposit nutrient-rich sediment vital for farming. The super-dam will upend this rhythm, trapping silt, shrinking Bangladesh’s delta already imperiled by rising seas and depriving Indian farmers of natural fertilization cycles. Saltwater intrusion and catastrophic floods would become more frequent.

But Beijing sees water not just as a resource; it sees it as power. By placing a mega-dam just before the river leaves Tibet, China would acquire a hydraulic chokehold over hundreds of millions downstream.

Control over oil once defined global power. And, in the 21st century, control over transboundary rivers may prove just as decisive. With the dam, China would hold the ability to weaponize water without firing a shot.

The dam’s enormous price tag reflects not just ambition to generate enormous amounts of electricity but a determination to cement China’s hydro-hegemony through dominance over Asia’s lifelines. This would give Beijing the same strategic leverage over water as OPEC once enjoyed over oil — but with far greater immediacy for the daily survival of populations.

In fact, since annexing Tibet in 1951, China has become the source of cross-border river flows to more countries than any other upstream power. It has built more large dams than the rest of the world combined, with its spree since the 1990s focused on international rivers. Its 11 giant dams on the Mekong have already wreaked havoc downstream, deepening droughts and undercutting livelihoods in Thailand, Laos, Cambodia and Vietnam.

Yet Beijing continues to reject any form of water sharing. It has signed no water-sharing treaty with any neighbor, nor joined the 1997 U.N. Watercourses Convention — the only global treaty governing shared rivers — preferring instead to assert “indisputable sovereignty” over all waters within its borders.

The stakes extend beyond Asia. Tibet is warming twice as fast as the global average, accelerating glacier melt and permafrost thaw. With its towering height rising into the troposphere, the Tibetan Plateau shapes the Asian monsoons, stabilizes climate across Eurasia and influences the Northern Hemisphere’s atmospheric general circulation — the vast system of winds that helps define different climate zones by transporting warm air from the equator toward higher latitudes.

Tampering with the plateau’s hydrology is not just a regional gamble; it is a planetary risk. Altered river flows from Tibet will ripple outward into weather systems, food security and even migration patterns far beyond Asia.

If Beijing succeeds in monopolizing transboundary rivers, other states may be tempted to follow, eroding fragile cooperative frameworks elsewhere — from the Nile Basin to the Tigris-Euphrates. The mega-dam is thus not merely Asia’s problem but the world’s. The precedent it sets could destabilize water security worldwide at a moment when droughts and extreme weather are already straining societies.

This gargantuan dam is a geopolitical and ecological catastrophe in waiting, with its dangers already coming into view. Silence is complicity: The international community must press China to respect international water norms.

Brahma Chellaney, a professor of strategic studies at the independent New Delhi-based Centre for Policy Research and fellow at the Robert Bosch Academy in Berlin, is the author of nine books, including “Water: Asia’s New Battleground,” which won the Bernard Schwartz Book Award.