A glacial avalanche triggered a massive flash flood along Nepal’s northern border with Tibet on Wednesday, and the toll has continued climbing sharply since: officials now say at least 676 people have been killed in Nepal and seven in Tibet, with nearly 3,000 more still missing, including roughly 900 Nepali hydropower workers, at least 41 Australians, and up to 90 to 100 Americans, according to the U.S. State Department. Rescue efforts are now also racing against a new threat: a barrier lake formed by the landslide debris that authorities warn could breach and send another surge downstream.
The missing-persons count has grown sharply as more reports have come in: nearly 900 Nepali workers employed on hydropower construction projects are unaccounted for, according to the country’s Independent Power Producers’ Association, and at least 41 Australians remain missing alongside citizens from more than 30 other countries. India has set up a 24-hour control room and sent additional relief personnel, and Australia is sending aid along with extra consular staff. Officials continue to caution that both the death toll and the missing count are likely to keep rising as rescue teams reach areas still cut off by the flooding.
What Caused the Flood
Nepal’s foreign minister, Shishir Khanal, said an earthquake triggered a large ice-and-rock avalanche from a glacier that blocked the Bhote Koshi River, a tributary that eventually feeds into the Sun Koshi. The blockage built up a wall of water that gave way suddenly around 9 a.m. local time Wednesday, sending a surge downstream through the Bhote Koshi and Trishuli River valleys. Climate researchers at the Kathmandu-based International Centre for Integrated Mountain Development said the event fits the profile of a glacial lake outburst flood, a hazard that scientists have warned is becoming more frequent in the Himalayas as glaciers retreat.
Villages, Roads, and Power Projects Destroyed
The surge tore through valleys in Nepal’s Sindhupalchok, Rasuwa, Nuwakot, and Dhading districts, destroying homes, bridges, roads, and hydropower plants along the way. Video from the region shows muddy floodwater carrying away buildings and vehicles, with streets left buried under mud and debris in the flood’s aftermath.
The Toll Extends Into Tibet
China’s state broadcaster CCTV reported that a related landslide at the Gyirong Port checkpoint on the Tibetan side of the border killed three people, with 265 more listed as missing there. Footage circulating from the checkpoint shows the landslide descending in seconds as people on the ground scrambled to flee before mud and debris obscured the camera.
A New Barrier Lake Threatens Another Surge
The landslide debris that triggered the original flood has formed a new barrier lake near the source of the Bhote Koshi river system, and Chinese authorities warn there is a high risk it could breach, sending another surge downstream. China’s Ministry of Water Resources said continued rain could add millions of cubic meters of water to the lake, raising the risk of “renewed flooding and damage in downstream areas,” including the Gyirong Port checkpoint. Rescue operations were paused in some areas Friday as the lake began to overflow.
Rescue Efforts Underway
Nepal’s government has asked both India and China for help with search and rescue operations, and India’s air force has kept transport aircraft on standby to support relief efforts. Rescue crews are working to reach communities cut off by destroyed roads and bridges, and officials have cautioned that the number of confirmed dead is likely to rise as access improves to the hardest-hit areas.
Related from BeezLoop: Hundreds of Workers Feared Trapped in Nepal's Flooded Hydropower Tunnels, 29 Arrested After Flood-Swept Bank Safe Looted in Nepal and Indonesia Earthquake Death Toll Rises to 68 After 7.7 Magnitude Quake (Updated).
