A Debris-Dammed Lake Raises New Flood Fears on the Nepal-China Border

Rescue teams working through mud and debris near the Nepal-China border have been warned that a newly formed lake could create another dangerous flood downstream. Nepal’s disaster management authority said satellite imagery and preliminary assessments indicate that debris has blocked a river upstream, allowing water to accumulate. The warning came as authorities continued responding to a flash flood that killed hundreds of people and left more than 1,500 missing, according to the report. Nepalese officials have instructed security personnel, rescue workers and members of the public involved in relief operations to remain on high alert and move to safety immediately if conditions require it. Nepal Police spokesperson Abi Narayan Kafle said the rescue effort was continuing while authorities monitored the situation. Satellite images shown by Chinese state broadcaster CCTV placed the lake near the site of Wednesday’s glacial detachment event. CCTV reported that the barrier lake was more than 10 kilometers from Gyirong Port, a border crossing with Nepal that was inundated by mud and floodwater. The lake was reportedly at an elevation of about 2,950 meters—roughly 1,000 meters above the port. Qianggong Zhang, who studies climate and environmental risks at the International Center for Integrated Mountain Development, said another lake formed when an August 26 ice-rock avalanche blocked part of the valley. He said the lake had begun to overflow and contained a few million cubic meters of water, equivalent to about 1,200 Olympic-sized swimming pools. The risk is complicated by continued melting and debris along the river’s route. Jakob Steiner, a geoscientist at the University of Graz, said high temperatures were contributing to ongoing glacial melt and water accumulation at several points. Zhang and Steiner said the warnings should be taken seriously, particularly because rescuers searching for missing people could be exposed to additional danger. However, they also said another flood on the scale of Wednesday’s disaster was unlikely. The timing and extent of any further release of water remained uncertain in the supplied reporting.