Nepal and China halt rescue efforts as border barrier lake overflows

The death toll from the disaster that struck on Wednesday has already surpassed 470.Nepal and China have paused rescue efforts for survivors of the devastating flash flood that hit the border region two days ago as a “barrier lake” formed during the disaster began to overflow.Chinese rescue teams and vehicles were forced to pull back to safe ground, state broadcaster CCTV reported, as the risk of the lake bursting rose. Nepalese authorities also paused search operations for 90 minutes, an army officer confirmed.The “barrier lake”, formed as Wednesday’s flash flood carried huge volumes of mud and debris down a steep valley, is threatening to unleash another huge and destructive wave.In Nepal’s Rasuwa district, on the border with Tibet, residents were seen scrambling up hillsides to escape potential surges in the river level, according to the Reuters news agency.The barrier lake adds a new threat to communities devastated by Wednesday’s flash flood [EPA]The disaster unfolded as a glacier collapsed and sent a huge torrent of ice, water, rock, and mud down Himalayan river valleys, burying entire villages and destroying roads, bridges, and hydropower plants.In its wake, leftover debris trapped water to form a barrier lake, a natural dam created when landslides block a river.With water continuing to pour into the lake, the threat to downstream communities of another wave of flooding is rising.China has deployed an engineering team to conduct aerial surveys and 3D modelling of the site. By Friday, the lake’s volume had swelled to more than 2.5 million cubic metres, up from the estimated 1.5 to 2 million cubic metres recorded just a day earlier.