[Edaily Reporter Hong Soo-hyeon ] Nepalese police announced on the 28th that a landslide-dammed lake on the Tibetan side of the border with China had burst, causing flooding. A landslide-dammed lake is a naturally formed lake created when soil and rocks swept down by landslides or other causes block a river.

According to the Nepalese media outlet Ratopati, Nepalese police stated that day that the Yansha Lake on the Tibetan side, located in the upper reaches of the China-Nepal border, had burst again, posing a flood risk to downstream areas in Nepal.

On the same day, a drone operated by the Chinese Western Theater Command Air Force captured footage of additional glacial collapses on the Tibetan Plateau. Coincidentally, it was confirmed that a large amount of ice debris had fallen into the glacial lake, which was formed when landslide debris blocked the river’s course. The Chinese military explained that preliminary measurements estimated the volume at 50,000 cubic meters, or approximately 50,000 metric tons.

According to Chinese media, the glacial lake is currently about 150 meters long—roughly the size of an elementary school playground. The height of the sediment that has formed a dam is estimated at 50 meters, equivalent to an 18-story apartment building.

State-run Chinese media reports that the reservoir’s current water volume has exceeded 2.5 million metric tons, causing it to begin overflowing. To make matters worse, with rain forecast for the coming week, warnings have been issued that an additional 3 million metric tons of water will flow in over the next three days. This volume is equivalent to approximately 1,200 Olympic-sized swimming pools.

To gradually drain the water from Lake Yansha—formed by the landslide—and prevent its collapse, drainage channels must be dug in the lower sections; however, concerns about damage are growing because the steep slopes make it difficult for heavy equipment, such as excavators, to access the area.

Authorities in Nepal and China estimate that the inflow will peak around September 1, when the risk of the Yansha Lake collapse will be at its highest.

If the natural embankment holding back the Unsaek Lake collapses, the devastated border regions of Nepal and China could face another massive flood.

Nepalese police have issued an emergency alert instructing everyone in the Botekoshi and Trisuli river basins, as well as other at-risk areas, to immediately evacuate to safe locations.

The police also stated that they have requested all rescue workers and residents involved in rescue operations to cease their activities and move to safe locations immediately.

CNN reported that Nepal’s National Disaster Risk Reduction and Management Authority warned of a new flood risk in the Rasuwa area of the northern Bagmati Province. It urged residents and rescue workers to remain vigilant and to seek shelter immediately if they feel they are in danger.

It also reported that the water level of the Botekoshi River had risen sharply.

In a follow-up report, Ratopati stated that flooding caused by the overflow of Lake Unsaek had reached Shabrubhe.

According to The Guardian, Narendra Paryar, a senior official in the Rasuwa region, stated that due to the overflow of Lake Unsaek, “we can see that the river levels are rising.”

David Fisher, the International Federation of Red Cross and Red Crescent Societies (IFRC) representative in Nepal, expressed deep concern about the news of the Unsaek Lake overflow on the social media platform X, stating, “Red Cross teams are moving to safe locations and helping to spread the alert.”

Reuters reported that helicopter rescue operations in the Rasu area had been suspended due to the flooding of Lake Yunsak. Local residents were also seen climbing hills.

Due to the rugged mountainous terrain of the Rasuwa region, rescue operations are virtually impossible after sunset; with the suspension of search efforts, the chances of survival for the more than 1,200 people reported missing are becoming increasingly slim. Rescue authorities are reportedly using satellite imagery and other tools to monitor changes in water levels at the Tibet Dam and Lake Unsaek in real time while weighing when to resume the search.

Meanwhile, during the 2008 Sichuan earthquake in China, which claimed the lives of approximately 80,000 people, landslides formed in several locations, causing water levels to rise before the landslides collapsed, resulting in secondary damage.