'Ticking water bomb': China starts work on world’s largest dam near India's border

Strategic affairs expert Brahma Chellaney has shared on X (formerly Twitter) that China has officially acknowledged the construction of the world’s largest dam on the Yarlung Zangbo River, near the Indian border, a project he warns could become a “ticking water bomb” for northeastern India.

The massive hydropower project, announced by Chinese Premier Li Qiang at a groundbreaking ceremony in Nyingchi, southwest China’s Xizang autonomous region, will consist of five cascade hydropower stations. With an estimated investment of 1.2 trillion yuan (around $167.8 billion), the dam is set to dwarf the Three Gorges Dam and drastically alter river flows into India and Bangladesh.

Though Beijing officially announced the project only now, Chellaney pointed out that satellite images indicate construction may have begun soon after parliamentary approval in 2021.

Situated in a seismically active zone, the super-dam poses serious ecological and geopolitical risks. Experts fear it could destabilise downstream ecosystems, intensify regional water disputes, and significantly increase China’s leverage over India.

India has consistently expressed concerns over the lack of transparency and the absence of any bilateral or multilateral arrangements with China pertaining to water sharing.

Pema Khandu said in an interview with PTI, "This transcends state matters. This is a national concern. The country must take this threat seriously before it becomes too late."

As China is not a signatory to the 1997 UN Convention on the Law of the Non-Navigational Uses of International Watercourses, it is under no legal obligation to inform downstream countries like India and Bangladesh before constructing dams or redirecting water. Experts have long cautioned that such unilateral projects could alter the river's flow, particularly in dry periods, or even weaponise water in the event of a dispute.

Sudden releases from upstream dams could cause flash floods, wreaking havoc in downstream areas of Arunachal Pradesh and Assam. Khandu's comments reflect the increasing concern within Indian strategic circles about China's utilisation of infrastructure near critical borders for geopolitical gain. The dam’s site, in proximity to Arunachal Pradesh—a region that China claims as “South Tibet”—further complicates the situation. The implications extend beyond environmental issues; strategically, in times of conflict, the dam could be leveraged to induce flooding or restrict vital water supply to India’s northeastern regions.