After floods hit Tibet and Nepal, safety questions mount over China’s plan to build world’s largest dam

Devastating floods in Nepal have raised safety concerns about China's plan to build the world's largest dam on the Yarlung Tsangpo/Brahmaputra River. The massive hydropower project, costing 1.2 trillion yuan, began construction in July 2025 in Nyingtri, Tibet. By leveraging a 2,000-meter drop over 50 kilometers of the river, China aims to generate 300 billion kilowatt-hours of electricity annually, three times the output of the Three Gorges Dam.

The Yarlung Tsangpo, which begins in China and flows through India, Bhutan, and Bangladesh, is particularly vulnerable to disasters due to tectonic movements in the Himalayan region. Chinese researchers warn that a combination of underground faults and retreating glaciers could trigger landslides, collapses, and debris flows.

The recent floods in Nepal have prompted experts to warn that the super-dam project could further increase the region's vulnerability to earthquakes and landslides. To harness the significant drop in elevation, water must be diverted through a tunnel, which could lead to large amounts of soil being excavated, potentially exacerbating seismic risks.

Glacier expert Anil Kulkarni from the Indian Institute of Science told the Financial Times that hydroelectric dam construction and development in the Himalayas are increasing the region's vulnerability to glacier collapses. Jagannath Panda, head of the Stockholm Center for South Asian and Indo-Pacific Affairs, noted that the Yarlung Tsangpo project could contribute to greater seismic risks and landslides.

China has acknowledged the need for increased safety management and risk assessments for the project. On Aug. 11, the National Energy Administration announced it would strengthen safety measures and conduct risk assessments for major projects in extreme environments. A comprehensive risk monitoring, early-warning, and control system is also being established.

On Aug. 27, the acting mayor of Nyingchi visited the debris-flow mitigation works in Mêdog and ordered increased geological hazard monitoring and information sharing. China and Nepal have also discussed transnational disaster information sharing, with Beijing sharing images, satellite data, and hydrological data of the affected area, including early warning information of the upstream barrier lake. They agreed to strengthen disaster response efforts and real-time sharing of hydrological data.