China starts building world's largest hydroelectric dam on Yarlung Tsangpo

China began construction in July 2025 on the Motog (Medog) hydro‑power project on the Yarlung Tsangpo River in Tibet, just 50 km from the Line of Actual Control with India. The scheme is planned to produce 60–70 GW of capacity (about 60,000 MW) and generate roughly 300 TWh of electricity each year, at an estimated cost of $167‑170 billion.

The river flows into India as the Siang and then the Brahmaputra, supplying water to over 130 million people in India and Bangladesh. Indian officials have responded by accelerating the 11,000 MW Siang Upper Multipurpose Project in Arunachal Pradesh, citing strategic and flood‑control benefits. Experts warn that the Chinese dam could allow upstream regulation of water releases, raising downstream flood‑risk and ecological concerns, especially in the seismically active Himalayan terrain.

Environmental groups highlight the project's location in a biodiversity‑rich, earthquake‑prone zone, noting potential impacts on sediment transport and river ecology that could affect agriculture and delta stability downstream. The project is also framed by Beijing as part of its decarbonisation strategy, while some analysts question its long‑term sustainability and economic justification.