A glacier collapse dammed the river, and researchers are watching the new barrier lake grow
Debris from Wednesday's ice and rock avalanche blocked a river upstream in the high Himalaya. The barrier lake behind it sits at 2,950 m, about 10 km from the Gyirong Port crossing, and holds a few million cubic metres of water. China's water ministry said the lake has pooled 1.5 to 2 million cubic metres and that about 3 million more could arrive in three days; researchers warn that a loosely packed debris dam could fail suddenly.
Science··Midday
Avalanche debris formed two barrier lakes
Debris from Wednesday's ice and rock avalanche blocked a river upstream in the high Himalaya. The barrier lake behind it sits at 2,950 m, about 10 km from the Gyirong Port crossing, and holds a few million cubic metres of water. Experts quoted by Al Jazeera describe an avalanche-induced barrier lake where the ice-rock mass blocked the valley drainage. Satellite imagery and drone footage confirmed two lakes after the event: one upstream in China fed by melted glacial water, the other on the Lehende river where a mudslide dammed the channel.[1], [2]
Water volume and dam strength keep flood risk high
The flash flood along the same stretch killed hundreds and left more than 1,500 people missing. On Thursday China's water ministry estimated the lake holds 1.5 to 2 million cubic metres and warned that about 3 million more could flow in over three days, a volume likened to roughly 1,200 Olympic-sized swimming pools. Pawan Bhattarai, who does research at Tribhuvan University, said the danger is sudden dam failure: in a steep valley even a brief breach can send a fast debris-laden flood downstream with little warning. Nepal's disaster management authority is following the lake with satellite imagery, and experts at the International Center for Integrated Mountain Development are watching it alongside reporting from the Chinese broadcaster CCTV.[1], [2]
Rescue work resumes as Nepal declines outside help
Rescue efforts in hard-hit Rasuwa district were slowed by floods and mudslides; they paused on Friday when the barrier lake briefly overflowed, then resumed. the Chinese broadcaster CCTV said the overflow risk was manageable. A World Health Organization official reported six damaged health facilities and eight missing health workers. Foreign ministry spokesperson Lok Bahadur Chhetri said search and rescue teams keep working and that Nepal does not need outside help for now. Specialists quoted in the reporting do not expect a repeat as destructive as Wednesday's, while warning that continued glacial melt and water accumulation make the alerts worth taking seriously.[2], [1]
