Nepal-Tibet Border Barrier Lake Fully Drains, Easing Secondary Flood Fears, China Says

Kathmandu: Relief washed over communities along the Nepal-China border on Sunday as Beijing’s Ministry of Water Resources confirmed that a volatile barrier lake—born from last week’s massive ice-rock avalanche—has safely emptied through natural channels, defusing the immediate threat of a catastrophic downstream breach.

The temporary reservoir formed last Wednesday when an immense ice-rock avalanche on Langtang Ri’s northern face blocked the confluence of the Chhochen Khola and Purepu Tsangpo rivers, triggering a destructive surge down the Bhotekoshi basin. State media reported that roughly 2 million cubic metres of water had initially backed up behind the debris, prompting urgent flood warnings from Chinese authorities who feared heavy rains would cause the natural dam to burst.

Satellite tracking ultimately revealed a gradual, controlled discharge rather than a sudden rupture. Nitesh Khadka, a Nepali researcher with the Chinese Academy of Sciences in Chengdu, corroborated the ministry's findings after reviewing field photographs from colleagues, noting that the lower blockage had completely cleared and the upper lake had also shed more than half its volume.

The development comes as river levels rose again in the Bhotekoshi and Trishuli river systems on Sunday, raising fresh concerns in areas already devastated by Wednesday’s disaster. Swollen waters along the Trishuli and Bhotekoshi systems drove riverbank erosion through Nuwakot and Dhading districts. A severe landslide sparked by flood erosion at Krishnabhir in Dhading completely severed the vital Muglin-Kathmandu corridor of the Prithvi Highway, while surging currents elsewhere swept away a suspension bridge connecting Ghyachok in Gorkha to Charaudi in Dhading.