NEW DELHI (Diya TV) — A new geological study has raised fresh questions about the safety of China’s massive Medog Hydropower Station on the Brahmaputra River in Tibet. Researchers linked to China’s state-run geological survey found that the project sits above an active fault line. As a result, experts say the location could create serious engineering and seismic challenges for what is expected to become the world’s largest hydropower project.
The Medog Hydropower Station stands about 50 kilometers from China’s border with Arunachal Pradesh. The project has already drawn attention because of concerns about its possible impact on downstream water flow into India and Bangladesh. Now, however, the latest findings have shifted attention toward the site’s geological risks.
According to the South China Morning Post, researchers published their findings in the Mandarin-language journal Sedimentary Geology and Tethyan Geology. The study identified the active Paizhen Fault directly beneath the Medog dam site on the Yarlung Tsangpo River, which becomes the Brahmaputra after entering India.
The research team included geologists from Chengdu University of Technology, the Civil-Military Integration Centre of the China Geological Survey, and the Middle Yarlung Zangbo River Natural Resources Observation and Research Station. The scientists warned that the fault could threaten the long-term stability of the dam and other nearby infrastructure.
The Medog Hydropower Station will generate about 60,000 megawatts of electricity. China approved the project in December 2024 and started construction in July 2025. Officials expect commercial operations to begin in 2033. The project carries an estimated price tag of more than 1 trillion yuan, or about $137 billion. It could produce around 300 billion kilowatt-hours of electricity every year, nearly three times the output of the Three Gorges Dam.
However, the new study says the Paizhen Fault has remained highly active since the Pleistocene epoch, which began about 2.6 million years ago. Researchers believe future movement along the fault could damage dams, roads, bridges, tunnels, and nearby reservoir areas.
The study also highlighted the seismic history of the region. Ancient lake deposits suggest the fault remained active as recently as 9,500 years ago. In addition, a magnitude 6.9 earthquake struck the northern end of the fault in Tibet in 2017. Researchers said that the event provided more evidence that the fault still has significant seismic potential.
The scientists also found that repeated fault movement has weakened the surrounding rock. They said fractures have reduced the strength of the ground beneath the project. Therefore, the foundation may struggle to support the enormous weight of the dam and its reservoir during future earthquakes.
Furthermore, the researchers warned that the slopes around the reservoir contain loose material with weak cohesion. Once water fills the reservoir, long-term saturation could increase the risk of landslides and slope failures. Earthquakes or renewed fault activity could make those hazards even worse. Because of these risks, the team recommended stronger protective measures, including slope reinforcement and retaining structures during construction and future operations.
Meanwhile, the project continues to attract attention across South Asia. India and Bangladesh have closely watched the dam because both countries rely on the Brahmaputra River. Earlier debates focused on whether China could control the river’s flow into India. Those concerns gained attention after India suspended the Indus Waters Treaty with Pakistan.
Still, some experts believe geological safety deserves greater attention than water control. Nilanjan Ghosh, an economist and water expert at the Observer Research Foundation, told India Today Digital that fears of China cutting off the river remain overstated. He explained that the Yarlung Tsangpo contributes only about 10% to 15% of the Brahmaputra’s total flow. Most of the river’s water comes from tributaries and heavy monsoon rainfall after it enters India.
Ghosh also said any major effort to block or divert the river would create problems upstream. Sediment would build up behind the dam and increase the risk of flooding inside China. As a result, such a move would not serve China’s own interests.
