GORKHA (Nepal): The International Centre for Integrated Mountain Development (ICIMOD) has identified the failure of a temporary landslide-induced river blockage as the probable cause of flash floods in Nepal’s Budhi Gandaki river corridor.
In a press release, the regional intergovernmental learning and knowledge sharing centre said the flash flood “may have been triggered by the failure of a temporary river blockage created by a landslide near Chumchet in Gorkha district, according to preliminary accounts from Nepal’s authorities…”
In its preliminary assessment, ICIMOD estimated that the flooding began at around 4 am Nepal time on October 11, carrying mud, sediment and debris downstream through the Budhi Gandaki corridor.
A flash flood swept through Nepal’s Budhi Gandaki river system early on 11 October, carrying mud, sediment and debris downstream.
Preliminary accounts indicate that the failure of a temporary landslide blockage near Chumchet, Gorkha, may have triggered the event.
With search, rescue and evacuation efforts are underway, our prayers are with everyone affected. We stand in solidarity with the Government of Nepal providing technical support as required.Read the full press release: https://t.co/PfTLvT2Tcf
— ICIMOD (@icimod) October 11, 2026
Recounting the early-morning evacuation, Kamala Duwadi, a resident of Arughat in Gorkha district, said she and other residents moved to higher ground after receiving warnings about the approaching flood.
“In the morning, an alert was issued to us. I was inside my home and I came out hearing the sounds outside; the police were making public announcements for the evacuation. It was around 4:30 in the morning. I own a shop here and some of the workers who live upstream also called and warned about the incoming flood situation and explained that they also ran to higher ground for safety and asked us to move to safe ground. The fear of the Bhotekoshi flood is still in mind; we quickly moved out from here to the higher ground up in the hills,” Duwadi said.
🇳🇵🌊 Flash flood on Nepal’s Budhi Gandaki sweeps away dozens of homes and bridges in Gorkha; four to ten people reported missing
A flash flood carrying mud and debris hit the Budhi Gandaki River in northern Gorkha district around 4 a.m. on Oct. 11. Local officials estimate 35 to 40 houses were swept away in Jagat Bagar, Salleri and Ghattikhola in Chumnubri Rural Municipality. The Soti Khola bridge near Arughat was completely washed away, and a 22-meter section of the Arughat bridge linking Gorkha and Dhading was destroyed, according to Nepal’s Department of Roads. Radio Nepal, citing an assistant chief district officer, reported six bridges swept away, two motorable and four suspension; other outlets count fewer. Parts of a hydropower project under construction in Salleri were also destroyed. Six people were airlifted from landslide-threatened Jagat village, and residents of Machhakhola, Soti, Arkhet and Arughat were told to move to higher ground. The river remains above the danger level. Reported by Kathmandu Post, Himalayan Times, OnlineKhabar and Radio Nepal.
Reports vary: at least ten missing per Radio Nepal, five per the Kathmandu Post, four per other outlets. I found no confirmed deaths. Claims of around 150 flooded homes downstream in Arughat are unverified.
Preliminary reports point to a landslide above Siuribas; residents suspect the Syar stream, a tributary of the Budhi Gandaki, may have been blocked. This is not confirmed.
The flood comes weeks after floods and landslides in August killed at least 1,455 people, with 5,285 missing as of Oct. 5, according to Reuters. A separate avalanche has left 14 Nepalis missing on Himlung.
A river that fluctuates above danger level, damaged bridges and a possible landslide dam make the next hours as dangerous as the first. What to watch: the final missing count, whether the river keeps rising, evacuation of downstream villages, and the cause of the surge.
Sources: Kathmandu Post; Himalayan Times; OnlineKhabar; Radio Nepal; The Statesman; Reuters (via Daijiworld).
— 🔥🗞The Informant (@theinformant_x) October 11, 2026
Initial reports indicate that people are missing, houses have been washed away, bridges have been lost and riverside infrastructure has been damaged. Damage has also been reported at the 341 MW Budhi Gandaki hydropower site at Selleri, although the full extent of the losses remains under assessment.
The latest incident comes shortly after the Gyirong-Rasuwa disaster, highlighting the risks posed by cascading mountain hazards, in which one event can trigger another and amplify the impact on communities and infrastructure.
The latest flooding follows another major flood-generating event in the same valley in April 2024, when a massive ice avalanche from the snout of the Manaslu Glacier plunged into Birendra Tal, triggering a sudden overflow into the Budhi Gandaki River.
A detailed ICIMOD-led assessment found that the event was caused by displacement of lake water following the ice avalanche, rather than a glacial lake outburst flood (GLOF). “Together, the two events highlight the range of hazards capable of generating destructive floods in Himalayan river systems and the importance of monitoring multiple sources of risk,” ICIMOD stated.
“Coming so soon after the Gyirong-Rasuwa disaster, this event is another reminder of how exposed mountain communities and river corridors remain to sudden, cascading hazards,” said Pema Gyamtsho, Director General of ICIMOD. “While response efforts must remain the immediate priority, understanding what triggered this flood will be critical for reducing future risks and strengthening resilience.”
The Budhi Gandaki flood also highlights the vulnerability of settlements, transport networks, energy infrastructure and essential services located along mountain river corridors. As response efforts continue, understanding the interaction between slope instability, river dynamics and downstream exposure will be crucial for risk reduction, infrastructure planning and recovery efforts across the Himalayan region.
“Current analysis points to the possible failure of a temporary landslide blockage that released a heavily sediment-laden flood downstream,” said Qianggong Zhang, Strategic Lead on Climate and Environmental Risks for ICIMOD. “Events like this demonstrate why monitoring and evaluating unstable slopes and river systems together is essential in steep mountain catchments, where hazards can develop rapidly and affect communities far downstream.”
ICIMOD notes that future risk assessments, infrastructure planning and recovery efforts should account for multiple hazards, their triggering mechanisms and their cascading downstream impacts, particularly in river corridors where settlements, transport networks, energy infrastructure and essential services remain highly exposed to sudden-onset hazards. (ANI)
