(TibetanReview.net, Aug10’26) – China has already been wielding the hydrological data it controls in occupied Tibet as a weapon against India, refusing to share it despite an agreement after bilateral relations turned sour in the aftermath of the 2020 Galwan Valley border clashes. China’s recent decision to begin building the world largest ever hydro-electric dam over the Yarlung Tsangpo just across its Arunachal border over a seismically active terrain has only raised the weaponization danger manifold. Hence, during the 36th meeting of their Working Mechanism for Consultation and Coordination (WMCC) on India‑China Border Affairs held in New Delhi on Aug 6, India sought greater hydrological cooperation from China, said Indian media reports Aug 7.
India’s push for greater transparency comes as the two countries seek to stabilise their broader relationship after years of tensions along the Line of Actual Control (LAC), reported firstpost.com Aug 7, adding river data remains a key part of India-China talks.
India asked China to resume sharing hydrological data on the Brahmaputra (Yarlung Tsangpo in Tibet) river and provide technical details of upstream projects, amid growing concerns over Beijing’s construction of what is expected to be the world’s largest hydropower dam on the Yarlung Tsangpo in Tibet, said moneycontrol.com Aug 7.
It cited a statement issued by India’s Ministry of External Affairs (MEA) on Aug 7 as saying India stressed the need for an early meeting of the Expert Level Mechanism on trans-border rivers and underscored the importance of timely sharing of water-flow data and technical information related to upstream infrastructure projects.
A Bloomberg report was cited as saying the dam, which began to be build in Metog County of Tibet’s Nyingtri City in Dec 2025, was expected to cost around 1.2 trillion yuan (about $178 billion), making it the world’s most expensive hydropower project, and take 10 years to build.
Earlier too, at the WMCC meeting in Beijing in May, New Delhi stressed the need for an early meeting of the expert-level mechanism on trans-border rivers, said the firstpost.com report.
The report noted that the demand for hydrological information was particularly important for India because changes in river flows could have implications for flood forecasting and management in downstream areas. An existing India-China arrangement already provides for China to share hydrological information on the Yarlung Tsangpo/Brahmaputra during the flood season.
The report said that for New Delhi, the dam issue comes against the backdrop of a gradual attempt to rebuild India-China ties. The two sides have held diplomatic engagements and border talks since reaching agreements to ease the military standoff in eastern Ladakh in 2024.
While border stability remains central to the relationship, the management of shared rivers represents another sensitive area where greater information-sharing and regular communication could become important as China’s Tibet project progresses, the report said.