Is Nepal Facing Another Flash Flood Threat? China Warns of Barrier Lake Breach Risk
Nepal faces a fresh flood threat after China warned that a newly formed barrier lake near the border could breach within three days. The lake already holds about 2 million cubic metres of water and is overflowing. The alert follows a deadly Bhotekoshi flood and a mudslide at China’s Gyirong Port that left 558 people missing.
Nepal is facing the threat of another major flood after China warned that a newly formed barrier lake near the Nepal-China border could breach within three days and send a fresh surge downstream. The lake had accumulated about 2 million cubic metres of water by Thursday morning, August 27, and was already overflowing, with another 3 million cubic metres potentially flowing into it over the next three days.
The warning comes a day after a glacier collapse triggered a deadly wall of water in Nepal’s Bhotekoshi river and a separate mudslide struck China's Gyirong Port crossing. With rescue operations already underway on the Chinese side and flood-hit communities in Nepal on alert, authorities are preparing for the possibility of another sudden rise in water levels. Nepal Flash Floods: Death Toll Rises to 160 As 761 People Remain Missing.
China Warns Of Barrier Lake Breach
China's Ministry of Water Resources said a significant barrier lake has formed near the confluence of the Chhochen Khola and Purepu Tsangpo rivers in Nepal. Its water volume was estimated at 2 million cubic metres as of Thursday morning, with the lake already overflowing. Another 3 million cubic metres of water is expected to flow into the lake over the next three days, posing a high risk of a breach, Global Times cited China Central Television (CCTV) report.
Chinese engineers are closely monitoring the lake and conducting flood simulations and analyses to assess the possible impact of a breach and prepare for emergency rescue efforts. Nepal has meanwhile advised residents living along the Bhotekoshi, Trishuli and Narayani rivers to stay away from the riverbanks until further notice. Nepal Flash Flood: PM Narendra Modi Speaks to Balendra Shah, Says ‘India Stands in Solidarity’.
What Caused The Bhotekoshi Flood?
Nepal's Department of Hydrology and Meteorology (DHM) says the initial flood was not caused by rainfall. Satellite images indicate that a large section of glacier, most likely from the north face of Langtang Lirung, broke away at an elevation of roughly 5,200 metres.
The ice mass reportedly crashed about 1,200 metres into the Lhende river, a tributary of the Bhotekoshi. The falling ice and rock blocked the narrow valley, creating a natural dam. When the obstruction gave way, a thick, muddy wall of water, ice and boulders moved downstream towards Rasuwa, Nuwakot, Dhading, Gorkha and Chitwan.
First Flood Wave Reached Chitwan
DHM data shows the flood surge entered Nepal around 9 am on Wednesday before moving rapidly downstream. The wave reached Devghat in Chitwan by late afternoon, where the flow peaked at nearly 5,850 cubic metres a second.
Around 20 million cubic metres of additional water passed through Devghat. The volume was several times that of the 1985 Dig Tsho glacial flood in the Everest region. The flood travelled almost 170 kilometres downstream within a matter of hours, highlighting the speed at which glacial and landslide-related floods can move through Himalayan river systems.
Mudslide Hits China’s Gyirong Port
A separate disaster struck the same morning near Gyirong Port in China's Xizang region, an important trade crossing between China and Nepal. China's state broadcaster CCTV reported that mud reached more than five feet in some areas, cutting roads and communications.
Chinese authorities have mobilized rescue forces across multiple fronts. Emergency responders, the People's Liberation Army, engineering teams, telecom operators and relief organisations have deployed personnel, aircraft, equipment and supplies as the search continues.
As of Thursday morning, three people had been confirmed dead, two had been rescued and 558 remained missing, including 260 foreign nationals. Officials have not formally confirmed whether the mudslide and the Bhotekoshi flood were caused by the same event.
Why Is The Himalayas Facing More Flood Risks?
The latest disaster comes just 14 months after another flood struck the same stretch of the Bhotekoshi river in July 2025. That event was linked to a lake sitting on top of a glacier.
The International Centre for Integrated Mountain Development says the number of glacial lakes in the Himalayas has increased from around 1,900 to more than 2,600 since 2005.
The region is warming faster than the global average, increasing concerns about unstable glaciers and the growth of glacial lakes. Such changes can raise the risk of sudden glacial lake outburst floods and other destructive events.
Rescue Operations Continue
On the Chinese side, rescue teams are working amid difficult terrain, continued rainfall and the risk of secondary disasters.
Authorities are simultaneously monitoring the newly formed barrier lake and preparing for a possible breach.
In Nepal, officials are keeping vulnerable communities along major rivers on alert as they assess whether the additional water entering the barrier lake could produce another dangerous flood surge downstream.
The immediate concern remains whether the barrier lake can withstand the expected increase in water volume over the next three days.
(The above story first appeared on LatestLY on Aug 27, 2026 06:38 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).