2/5 Of the 3000-km river, 1,700 run through Tibet, emerging from glacier Angsi near Mansarovar. It is the world’s highest river, with the steepest gradient and large parts of it still remain unexplored. The dam might involve boring about 20 tunnels through Namcha Barwa, the 25,551-ft Himalayan peak. The tunnels would bring the water down from 900 metres to about 2000 where turbines might be located. Then the water can rejoin the river as it enters India.