Brahmaputra in Peril as China, India Tighten Water Grip

The Brahmaputra, which accounts for about 70% of Bangladesh’s natural dry-season water flow, plays a critical role in sustaining agriculture and rural livelihoods. Yet, both China and India are moving aggressively to harness the river for energy and irrigation—raising fears of disastrous consequences downstream.

China is pursuing what would be the world’s largest hydroelectric project on the Brahmaputra (known as the Yarlung Tsangpo in Tibet), aiming to reroute 70% of the river’s water to generate 60 GW of electricity—more than twice Bangladesh’s current installed capacity.

India, not far behind, is advancing plans to dam the Siang River, a major Brahmaputra tributary, with a project capable of storing large volumes of water to generate 11 GW of power.

"The basic idea is for upstream countries to take water as needed and promise to return what's left," said Md Khalequzzaman, geology professor at the Commonwealth University of Pennsylvania. He explained that China’s rerouting would involve constructing dams, tunneling through mountains, and using gravity to power turbines over a 50-kilometre stretch.

Despite the scale of these projects, little is publicly known. China and India have not shared feasibility studies or environmental impact assessments with Bangladesh, leaving downstream communities in the dark.

“This is not new,” said Tuhin Wadud, director of Riverine People, a civil society group. “India has long diverted Teesta River water, turning it into parched land in dry months. Now they plan the same for the Dharla—another key Brahmaputra tributary.”

Experts warn of severe consequences. “Bangladesh faces a grave threat,” Khalequzzaman said. “There’s no reason to trust vague promises of fair water use while the natural flow is being disrupted.”

The 2,900-kilometre Brahmaputra, rising near Mount Kailash in Tibet and cutting through India before entering Bangladesh, is one of the world’s most dynamic rivers. It flows through one of Earth’s most active fault zones, where several major earthquakes have occurred over centuries.

Building megadams in such a seismically volatile region, experts argue, is not only risky but potentially catastrophic. China’s proposed project would dwarf even the Three Gorges Dam and carry a staggering $137 billion price tag. The planned drop in elevation—5,000 metres—is about five times the height of Bangladesh’s highest peak.

Combined with rapid glacial melt from climate change, the risk of sudden dam bursts increases dramatically, as recent events have shown.

Environmentalists also warn of slower but equally destructive consequences: trapped sediments, riverbed erosion, soil infertility, and collapsing aquatic ecosystems. Once rivers stop carrying sediment to the coast, the delta-building process stalls—and saltwater creeps in.

“In the 1960s, transboundary rivers brought nearly 2 billion tons of sediment to Bangladesh each year. Now it’s down to 1 billion,” said Malik Fida A Khan, executive director of the Center for Environmental and Geographic Information Services (CEGIS). “That decline has direct consequences for coastal resilience.”

Bangladesh has no formal water-sharing agreement with China or India over the Brahmaputra. Nor are any of the three countries signatories to the UN Convention on the Law of the Non-Navigational Uses of International Watercourses.

Despite repeated requests—including one earlier this year—China has refused to share data or impact assessments for its mega-dam. Joint Rivers Commission member Mohammad Abul Hossen confirmed that Bangladesh’s requests dating back two years remain unanswered.

“Properly managed, dams could help with flood control,” Hossen noted. “But without transparency or cooperation, they pose far more risks than benefits.”

Experts are urging China and India to conduct a joint Strategic Environmental Assessment (SEA) and to include Bangladesh in any decision that affects shared water resources. They’re also calling on Bangladesh to take proactive steps—such as signing the UN watercourse convention and pressing India diplomatically to push back against China’s unilateral moves.

Bangladesh should seize this moment, they argue, to spotlight India’s record on the Teesta River and the lasting damage caused by the Farakka Barrage. There, sudden water releases during monsoon and dry-season shortages have uprooted hundreds of families, destroyed fish stocks, and worsened erosion.

The dangers are not theoretical. As noted by Australia’s Lowy Institute in a 2020 report, control over rivers originating from the Tibetan Plateau gives China a “chokehold” not only over Bangladesh but also India’s economy.

As both upstream powers race to control the Brahmaputra, Bangladesh stands at a perilous crossroads—caught between regional power plays, climate threats, and an increasingly uncertain water future.