Nepal and China Suspend Rescue Operations as Overflowing Barrier Lake Threatens Border Region

Nepal and China have temporarily halted rescue efforts for survivors of the catastrophic flash flood that struck the border region two days ago after a "barrier lake," formed during the disaster, began to overflow. State broadcaster CCTV reported that Chinese rescue teams and vehicles were forced to retreat to safe ground due to the escalating risk of the lake bursting. A Nepalese army officer also confirmed a 90-minute pause in search operations.

The barrier lake, created when Wednesday’s flash flood swept vast quantities of mud and debris down a steep valley, now threatens to unleash another massive and destructive wave. According to the Reuters news agency, residents in Nepal’s Rasuwa district, situated on the border with Tibet, were seen fleeing up hillsides to escape potential river level surges.

The disaster began when a glacier collapsed, sending a massive torrent of ice, water, rock, and mud down Himalayan river valleys. The debris subsequently blocked a river, creating a natural dam or barrier lake. With continuous water inflows, the danger of downstream flooding has intensified. China dispatched an engineering team to perform aerial surveys and 3D modelling of the site, noting that the lake’s volume swelled to over 2.5 million cubic metres by Friday, up from 1.5 to 2 million cubic metres the previous day.

Downstream in Nepal, Narendra Pariyar, the top administrator in the hard-hit Rasuwa district, stated that officials received warnings of the lake breaching its bank. "We can see that the level of water in the river is rising," he noted, though the exact surge height remains uncertain.

The disaster's death toll has surpassed 470. On Friday, the Nepalese prime minister’s office reported 469 confirmed deaths, 977 missing individuals, and approximately 1,550 rescues. Meanwhile, Chinese authorities announced that the death toll in Tibet rose to at least five, with 558 people missing. Bishal Nath Upreti, president of the Nepal Centre for Disaster Management, told Al Jazeera that conditions remain "extremely difficult" for those trapped as destroyed roads isolate the disaster zone. Airlifts and ground operations have successfully rescued about 800 people by helicopter and 700 by land.

Al Jazeera’s Katrina Yu, reporting from Beijing, stated that the number of missing persons is anticipated to climb. China has deployed approximately 500 military and paramilitary personnel alongside Premier Li Qiang to oversee ground operations, while Nepal has deployed 30,000 security personnel to search isolated valleys. The Red Cross reported on Friday that over 90,000 people have been affected by the disaster, with relief supply deliveries currently blocked by the overflowing lake. "We’re of course very concerned about the secondary flood," said David Fisher, head of delegation for the International Federation of Red Cross and Red Crescent Societies in Nepal.