Fresh avalanche and overflowing barrier lake disrupted rescue operations in Nepal, with a second, larger upstream lake growing without an outlet, keeping flood risks high.
Rescue teams on both sides of the Nepal-Tibet border were repeatedly forced to reassess and retreat Friday as an unstable barrier lake overflowed into Bhote Koshi, sent a fresh surge downstream and briefly halted operations, only for another avalanche hours later to dump an estimated 50,000 cubic metres of ice debris towards the impounded water. Because ice clings to steep slopes and can break away suddenly, hanging glaciers can be particularly hazardous.
Officials said flood risk would remain until both lakes drained. Chinese embassy in Kathmandu said the lake remained at a high level and was overflowing. “The situation is currently at a critical stage for rescue and emergency response,” an embassy spokesperson said. “But given what has happened with the nearby glacier, we are trying to monitor this as much as possible,” an official from Nepal’s department of hydrology and meteorology told a climate news website.
Satellite images later showed an even more worrying development — a second, larger upstream lake was still growing and had no visible outlet. Nepal planned to install cameras and sensors downstream while relying meanwhile on satellite imagery to track the lakes. Officials cautioned that the fissures could have existed for years and did not by themselves indicate an imminent collapse. Catch the latest World News and Live updates. Download the TOI app.
Separately, Nepal closely monitored two glaciers next to the one that collapsed from Langtang Lirung on Wednesday after Chinese drone images appeared to show cracks in the ice, raising concern over slopes feeding the same Lhende river system.
Its volume had risen to more than 2.5 million cubic metres from an estimated 1.5-2 million cubic metres a day earlier. Nepal halted helicopter rescue operations in Rasuwa for around 90 minutes, while residents in vulnerable areas moved to higher ground.
Nepal had initially received information that the barrier lake had “breached”, but later assessments did not confirm a catastrophic dam failure. The immediate scare began Friday morning when the debris-dammed lake near the Chhochen Khola-Purepu Tsangpo river system, upstream of the Gyirong-Rasuwagadhi corridor, began overflowing. China ordered all rescue personnel and vehicles downstream to withdraw to designated safe areas amid fears that the debris barrier could fail and trigger another flood, landslide or avalanche. The fresh surge travelled downstream through Bhote Koshi towards Trishuli, prompting warnings to settlements along the river corridor.