Nepal’s National Disaster Risk Reduction and Management Authority (NDRRMA) and China’s Ministry of Water Resources have issued urgent warnings regarding a massive newly formed barrier lake upstream near the Nepal–China border. The site of the blockage is located near the confluence of the Chhochen Khola and Purepu Tsangpo (Lhende River) in Tibet, roughly 18 km upstream from the Rasuwagadhi border crossing.
Satellite assessments and hydrologic data confirm that an ice-rock avalanche and glacial collapse impounded the river, creating a temporary dam estimated to be nearly 50 meters high. Approximately 2 million cubic meters of water have already accumulated behind the debris wall, with an additional 3 million cubic meters projected to drain into the basin over the next 72 hours. The natural dam has begun overtopping, raising severe concerns of an imminent full structural breach that would trigger a secondary catastrophic outburst flood downstream.
Rising Casualty Figures and Widespread Destruction
The initial flash flood wave, which surged through the Bhote Koshi and Trishuli river corridors without prior warning, has claimed hundreds of lives. Over 390 deaths have been confirmed across border regions, including hard-hit districts such as Rasuwa, Nuwakot, Dhading, and Chitwan. Hundreds more remain unaccounted for, including local residents, security forces, border workers, and over 290 missing foreign nationals.
Extensive infrastructure damage has severed critical transport routes, leaving border towns like Timure and Syabrubesi isolated. The entire 42-kilometer highway stretch between Betrawati and Rasuwagadhi has been torn apart, with multiple concrete bridges destroyed. Hydropower facilities—including the Chilime Project—have sustained heavy damage, disrupting regional power grids.
Emergency Operations and Safety Directives
More than 13,000 security personnel alongside international emergency teams are carrying out search, rescue, and evacuation efforts. However, the immediate risk of a secondary dam burst has forced rescue operations along the immediate riverbanks to proceed with high caution.
Authorities have strongly advised all search-and-rescue teams, field personnel, and residents in riparian communities along the Bhote Koshi, Trishuli, and Narayani river networks to maintain safe distances from river channels and stay on high alert until the upstream barrier lake stabilizes. Cross-border satellite monitoring and 3D terrain mapping between Nepalese and Chinese hydrologic teams remain ongoing.