They say the remote region is almost impossible to access with the heavy equipment needed to build a megadam, and it lies in a heavily active seismic area, not far from the epicentre of one of the biggest earthquakes ever recorded.

Deadly landslides are also commonplace in this part of the world and would only be invited by a huge construction project.

The Yarlung Tsangpo is a transnational river system that becomes the Brahmaputra River in India, which provides 30% of the country’s water. It is feared the megadam project could reduce flows to India by 60%.