WEBDESK: India fears that China’s plan to build the world’s largest dam in Tibet could cut water flows into India by as much as 85 per cent in the dry season.
The river, known as the Yarlung Zangbo in Tibet and the Siang and Brahmaputra in India, comes from the Angsi Glacier and supports more than 100 million people across China, India, and Bangladesh.
Beijing announced in December that work had begun on a $170 billion hydropower project near the Indian border. India’s internal study, seen by Reuters, warns that China could divert up to 40 billion cubic metres of water each year a third of the flow India receives at a key border point.
Officials in Delhi fear China could use this control to “weaponise” water during the non monsoon season, when Indian farms most need irrigation.
Upper Siang dam: India’s response To China’s mega dam
To reduce risks, India is pushing forward with its own mega project the Upper Siang Multipurpose Storage Dam. With a storage capacity of 14 billion cubic metres, it could cut Guwahati’s water shortfall in dry months from 25% to 11%, according to estimates.
India also plans to keep 30 per cent of the reservoir empty, so it can absorb sudden releases from the Chinese dam without causing floods downstream.
But many in Arunachal Pradesh strongly oppose India’s dam. At least 16 villages could be submerged, displacing about 10,000 people.
The Adi community, which relies on rice, cardamom, and citrus farming, fears losing homes and farmland. “We will fight the dam to death,” said Odoni Palo Pabin, a local shopkeeper and mother of two.
Protests have already turned violent, with villagers blocking survey teams and damaging equipment. Some, however, have begun to cooperate after promises of compensation and new infrastructure.
China insists its dam will not harm downstream countries, saying it has carried out “scientific research” to ensure safety. But India’s Foreign Minister S. Jaishankar has raised the issue directly with his Chinese counterpart.
Experts warn that both planned dams lie in earthquake-prone areas, raising the risks of landslides, glacial floods, and structural damage.
Meanwhile, India itself has faced criticism. Earlier this year, Delhi suspended its role in a 1960 water treaty with Pakistan and suggested diverting some river flows away from its neighbour.
Even if approved, the Upper Siang dam could take more than ten years to complete, leaving India exposed until China’s project begins in the early 2030s.
With India and China already in dispute over borders, the battle for shared rivers could further damage relations.
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