A devastating flash flood has swept through Nepal's Rasuwa district, near the border with China, with authorities attributing the disaster to a massive snow-rock landslide. Initial studies, based on satellite imagery, suggest the landslide blocked the Lhende Khola river, leading to the formation of a temporary debris lake that subsequently burst, unleashing torrents of water and debris downstream.
Casualties and Missing Persons
The catastrophic event has resulted in a significant loss of life, with at least 98 people confirmed dead. The number of individuals reported missing, many of whom are tourists, has alarmingly risen to 579. Search and rescue operations are ongoing in the affected areas.
The Role of a Snow-Rock Landslide
Nepal's disaster management authority (NDRRMA) released findings from an initial study, which utilized satellite images from Planet Labs. This analysis points to a glacier-inclusive flood in the Lhende River, approximately 20 kilometers northeast of the Nepal-China Rasuwagadhi border crossing. The primary cause identified is a substantial snow-rock landslide.
Binod Parajuli, chief of the Department of Hydrology and Meteorology's Flood Forecasting Division, corroborated these observations. He cited preliminary satellite images from Chinese authorities, showing a significant blockage in the river upstream of the Miteri Bridge, caused by what appeared to be an icefall and landslide. This blockage created an ice and debris lake that eventually gave way.
Increased Destruction from Debris
Experts emphasize that the presence of extensive debris significantly amplified the flood's destructive power. Parajuli noted that if the flood consisted solely of clear water, the level of devastation would have been far less. However, the mixture of water and debris substantially increased the torrent's depth and force, leading to widespread damage to villages, roads, and bridges in its path.
Possible Earthquake Connection
Rijan Bhakta Kayastha, a climate researcher and professor at Kathmandu University, highlighted information suggesting an ice avalanche from the Nepal side blocked the Lhende river. Interestingly, a magnitude 4.4 earthquake was recorded by the US Geological Survey in Tibetan territory, about 47 km north of Gosainkunda, around the same time of the flood. While a direct causal link is yet to be established, the proximity in time raises questions about potential contributing factors.
Past Incidents and Future Concerns
This is not the first time the Bhote Koshi river system has experienced such a disaster. A similar flood occurred on July 8, 2025, which Nepal's Department of Hydrology and Meteorology later concluded was caused by a glacial lake outburst in the Lhende River area. Kayastha indicated that it could take several days to determine if a glacial lake outburst also contributed to the latest event, given the history of such incidents in the region.