The Bhote Koshi flood, and the warning Nepal already had.
Rock and glacier ice broke off Langtang Lirung at 5,200 m, inside a Nepali national park, and fell 1,200 m into the border stream below. The surge hit Rasuwagadhi before any warning went out, because nothing was watching that slope. Thirteen months earlier, the same river did the same thing.
Why it happened
The five-step cascade, and why permafrost is the reason these are accelerating.
What failed
Six documented failures, including an agreement signed in 2025 that never became a mechanism.
Damage & losses
748 MW, 19 bridges, the China trade gate and the Langtang gateway, sector by sector.
How long recovery takes
Melamchi took seven years for one headworks. Rasuwa lost more.
The world's response
Country by country and organisation by organisation, with what was actually pledged.
Affected areas & trek status
Five districts, the road, the border and the Langtang trail.
Every figure here carries its source and its hour
This event's published toll moved from 31 on the first morning to over 1,200 within eight days as recovery reached the lower Trishuli and Narayani. Rather than pick a number and imply certainty, we show what was reported, by whom, and when.
Confirmed dead in Nepal
1,410
Deaths confirmed by NDRRMA. The largest district counts are Chitwan 364, Nawalparasi East 232, Nawalparasi West 222, Nuwakot 203 and Rasuwa 199, with Gorkha, Dhading and Tanahun behind them. The toll rose from 31 on the first morning to over 1,000 within a week, and past 1,400 by mid-September, as bodies were found far downstream.
NDRRMA, via The Kathmandu Post ↗as of 18 Sep 2026, 9:00 am
Missing in Nepal
6,145
People reported unaccounted for, per NDRRMA. Its 17 September update counted 587 foreign nationals among them. 'Missing' still mixes the unaccounted-for with people out of contact.
NDRRMA, via The Kathmandu Post ↗as of 18 Sep 2026, 9:00 am
Injured in Nepal
5,135
Last reported on this basis on 3 September. 13,756 people rescued by NDRRMA's later count.
Nepal Police, via OnlineKhabar ↗as of 3 Sep 2026, 10:00 am
Missing across Nepal and Tibet
6,664
Nepal side plus 519 missing in Gyirong County, Tibet. About 590 foreign nationals from 39 countries are among the missing (Foreign Ministry).
NDRRMA and Xinhua, combined ↗as of 18 Sep 2026, 9:00 am
Confirmed dead in Tibet
43
Gyirong County, on the Tibetan side of the border. The avalanche fell from Langtang Lirung on the Nepali side into the Lhende Khola, the border stream, so Gyirong Port and Rasuwagadhi were hit together where it meets the Bhote Koshi. Gyirong Port is reported destroyed.
Xinhua, via Al Jazeera ↗as of 6 Sep 2026, 12:00 pm
Hydropower capacity damaged
748MW
14 projects: nine operating (354 MW) and five under construction (394 MW). NEA's first statement named only six facilities; the figure widened as assessments reached the upper valley.
Nepal Electricity Authority ↗as of 27 Aug 2026, 12:00 pm
Motorable bridges destroyed
19
Reported range 19–35
A further 45 suspension bridges are reported lost. Counts differ as districts report separately.
NDRRMA; higher count in later district returns ↗as of 27 Aug 2026, 9:00 am
First road & bridge damage estimate
Rs 15 billion
Roads and bridges only. It excludes hydropower, the customs corridor, housing and lost tourism, and will rise substantially.
Compiled official estimates ↗as of 27 Aug 2026, 12:00 pm
What happened, hour by hour
13 months earlier
10 July 2025
Context
The same river floods, and the warning is not acted on
A supraglacial lake on the Purugu Glacier in Tibet, at 5,150 m and 36 km upstream of Rasuwagadhi, bursts. Nine people are killed, 19 go missing, and the Nepal–China Friendship Bridge is destroyed. ICIMOD documents the lake expanding steadily between December 2024 and June 2025. At the time, Nepal has two functioning glacial-lake monitoring systems for 21 identified dangerous lakes, and the Bhotekoshi basin is not one of them.
08:37 NPT
26 August 2026
Cause
An ice-and-rock avalanche falls into the Lhende Khola
A slab of rock and glacier ice roughly 600 m wide breaks from the north face of Langtang Lirung at about 5,200 m, inside Nepal's Langtang National Park, and falls about 1,200 m into the Lhende Khola, the stream that marks the border. The GFZ Helmholtz Centre records the signal as a magnitude 4.4 event; USGS later reclassifies it as a landslide of Ms 5.2. Some analysis suggests the slope may already have failed on the afternoon of 25 August, with the river blocked for 18 to 19 hours; that is not yet settled.
≈08:44 NPT
26 August 2026
Impact
The surge hits Rasuwagadhi and Gyirong Port together
The debris runs down the Lhende Khola at up to about 190 km/h over its first 22 km, according to ICIMOD. CCTV footage captures it arriving at Gyirong Port roughly seven minutes after the seismic signal. Because the Lhende is the border, Rasuwagadhi on the Nepali bank and Gyirong Port on the Chinese bank are hit at the same confluence. Chinese authorities later describe the port as completely destroyed, with road access, communications and power severed.
≈09:15 NPT
26 August 2026
Impact
The warning goes out after the surge has already hit
The Flood Forecasting Division sends SMS alerts to about 679,000 people in four districts at 9:15–9:16 am, roughly ten minutes after the surge entered the Bhote Koshi. There is no warning for Rasuwagadhi or Timure. Rasuwa's Chief District Officer, Narendra Pariyar, says the flood struck without warning, coming down the border stream. The failure itself happened on Nepali soil, inside a national park, on a slope nobody was watching. Rasuwagadhi, Timure and Syabrubesi take the worst of it.
Morning
26 August 2026
Impact
The hydropower cascade goes down
Fourteen hydropower and transmission facilities along the Bhote Koshi and Trishuli are damaged, from Rasuwagadhi and Chilime at the top of the valley down through Trishuli 3A, the Trishuli 3B 220 kV hub substation and Devighat. The Rasuwagadhi customs office, Nepal's principal trade gateway to China, is destroyed.
Afternoon
26 August 2026
Response
Rescue begins; the first tolls are a fraction of the eventual count
The Nepal Army, Armed Police Force, Nepal Police and NDRRMA mobilise with military and private helicopters. The first confirmed toll is 31. Alerts go out to five districts downstream, as far as Chitwan.
Evening
26 August 2026
Response
International aid begins moving the same day
India flies ten tonnes of humanitarian and disaster relief supplies. The IFRC releases one million Swiss francs from its Disaster Response Emergency Fund. The International Charter on Space and Major Disasters is activated for satellite coverage.
Through the day
27 August 2026
Response
The toll multiplies elevenfold as the valley is reached
Confirmed deaths climb from 31 through 95, 165 and 175 to over 350, with roughly 1,400 missing across Nepal and Tibet. Nepal asks both India and China for help. Prime Minister Balen Shah calls for national unity and appeals for public contribution to the relief effort. The Department of Roads begins installing bailey bridges.
2:00 pm
1 September 2026
Response
Recovery passes 1,000 bodies; foreign missing put at 590
The Foreign Ministry's fourth briefing reports 1,010 bodies recovered, around 4,000 unaccounted for and more than 11,800 rescued, including about 324 foreign nationals. Some 590 foreign nationals from 39 countries remain missing. Forensic DNA teams from India and China work alongside Nepal Police on identification, and the government says it is moving from rescue to rehabilitation.
10:00 am
3 September 2026
Response
Nepal Police count: 1,252 recovered, 4,216 missing
Bodies have now been recovered in eight districts from Rasuwa to Nawalparasi West, and 18 in India. Nepal Police put the injured at 5,135 and the rescued at 11,993, with 95 bodies handed to families. Later counts on this page come from lib/disasters/toll.json and may be newer than this entry.
Evening
17 September 2026
Response
NDRRMA count: 1,410 dead, 6,145 missing
Three weeks on, NDRRMA puts the toll at 1,410 dead and 6,145 missing, 587 of them foreign nationals, with 13,756 people rescued. Chitwan has recorded the most deaths, 364, followed by Nawalparasi East, Nawalparasi West, Nuwakot and Rasuwa.
This was the second time, not the first
On 10 July 2025 a supraglacial lake on the Purugu Glacier burst 36 km above Rasuwagadhi and took the Friendship Bridge with it. Nine died. ICIMOD had watched the lake grow from a pond through the whole of the preceding winter and spring. The event was studied, reported and filed. Then the corridor was rebuilt the way it had been before, and the road crews were still working on it when the second flood arrived.
The same river, thirteen months apart
Nepal was given a rehearsal in July 2025. The first flood came from Tibet; the second began on Nepali soil. Neither basin was monitored, neither produced a warning in time, and in the thirteen months between them Nepal and China announced an information-sharing agreement that never became a mechanism.
| July 2025 | August 2026 | |
|---|---|---|
| Date | 8–10 July 2025 | 26 August 2026 |
| Trigger | Supraglacial lake outburst, Purugu Glacier | Rock-and-ice avalanche off Langtang Lirung into the Lhende Khola |
| Origin | 5,150 m, in Tibet | ~5,200 m, in Nepal (Langtang National Park) |
| Distance upstream | 36 km | Above Rasuwagadhi, on the Lhende Khola (the border stream) |
| Warning in time | None | None; SMS alerts went out after the surge hit Rasuwagadhi |
| Basin monitored | No | No |
| Dead in Nepal | 9–11 | 1,410 |
| Missing in Nepal | 18–19 | 6,145 |
| Border crossing | Friendship Bridge destroyed | Customs office destroyed |
The preparedness gap, drawn to scale
Nepal has identified 21 potentially dangerous glacial lakes. When the same river flooded in July 2025, 2 monitoring systems were working. The Bhotekoshi basin was not one of them.
2 of 21 identified dangerous glacial lakes were monitored.
Neither figure is the real indictment. Both floods came from outside Nepal, and no bilateral mechanism existed to tell Nepal either time.
13months
between the two floods on this river
36km
upstream where the 2025 lake sat, in Tibet
2/21
dangerous glacial lakes monitored in 2025
0
bilateral warning mechanisms, either time
A corridor Nepal cannot easily replace
748 MW, in one morning
Fourteen hydropower and transmission facilities were damaged. The named projects below are those identified in published reporting.
- Upper Trishuli-1216 MW
- Rasuwa Bhotekoshi120 MW
- Rasuwagadhi111 MW
- Sanjen Khola78 MW
- Chilime22 MW
- Langtang Khola20 MW
- Upper Mailung A6.42 MW
- Mailung Khola5 MW
748 MW
total damaged, 14 facilities
354 MW
nine plants already generating
394 MW
five still under construction
Named-project total shown here is 578.4 MW, of which 222.4 MW was operating. The balance of the NEA figure covers transmission assets including the Trishuli 3B 220 kV hub substation, Trishuli 3A, Trishuli and Devighat. Source: Nepal Electricity Authority.
The trade gate, destroyed twice in fourteen months
Rasuwagadhi is one of Nepal's two main trade crossings with China and its principal working one, directly north of Kathmandu. Its customs office was destroyed on 26 August. It had already been destroyed once in the July 2025 flood, and the crossing has been repeatedly closed for weather and infrastructure damage in the years since.
- Imports via this corridor
- Rs 163.73bn
- Distance to Kerung
- 24 km
Concentration risk nobody priced
Rasuwa is one of Nepal's densest hydropower districts, and it sits directly below an unmonitored transboundary glacial hazard. That combination is not an accident of this flood; it is the standing design of the valley. The 2025 event demonstrated the exposure and the build-out continued unchanged. See every plant in the cascade.
The Nepal Electricity Authority puts the total at 14 damaged hydropower and transmission facilities, about 748 MW: nine operating plants totalling 354 MW and five under construction totalling 394 MW. The named projects above are those identified in published reporting; the balance covers transmission assets including the Trishuli 3B 220 kV hub substation, Trishuli 3A, the Trishuli plant and Devighat. One naming caveat: flood reporting lists a 6.42 MW Upper Mailung A and a 5 MW Mailung Khola, while Amarnepal's own hydropower dataset carries a single Upper (Mathillo) Mailung Khola project at 14.3 MW. We have not been able to reconcile whether these are the same asset described differently or separate cascade stages, so both figures are shown as published rather than merged.
Settlement by settlement, down the valley
Rasuwagadhi, Timure and Syabrubesi took the worst of it. Alerts reached five districts, as far downstream as Chitwan.
| Place | District | Elevation | What was there |
|---|---|---|---|
| Rasuwagadhiरसुवागढी | Rasuwa | 1,850 m | Nepal's principal trade gateway to China, 24 km from Kerung. The customs office was destroyed, the second time this crossing has been wrecked in fourteen months. |
| Timureटिमुरे | Rasuwa | 1,780 m | The dry port and transit settlement below the border. Among the worst hit; most of the early helicopter rescues, 123 people, were lifted from here. |
| Syabrubesiस्याफ्रुबेसी | Rasuwa | 1,460 m | The road head and gateway to the Langtang trek, where the Bhote Koshi meets the Langtang Khola. Market area and river frontage destroyed. |
| Dhuncheधुन्चे | Rasuwa | 1,960 m | District headquarters of Rasuwa, and the coordination point for the response. |
| Mailungमाइलुङ | Rasuwa | — | Site of the Mailung Khola and Upper Mailung A hydropower projects, both damaged. |
| Betrawatiबेत्रावती | Nuwakot | 620 m | Where the Rasuwa road meets Nuwakot; the confluence of the Trishuli and Phalanku. |
| Trishuli Bazaarत्रिशूली बजार | Nuwakot | 540 m | The main downstream town. Its bridge was swept away. |
| Devighatदेवीघाट | Nuwakot | 520 m | The oldest plant in the cascade, at the bottom of the chain, also damaged. |
| Gyirong Portकेरुङ | Gyirong County, Tibet | 1,800 m | On the Chinese bank of the Lhende Khola, facing Rasuwagadhi across the confluence, so it was hit by the same surge at the same moment. Reported completely destroyed. Early counts put 558 missing in the county, including 260 foreign nationals; Xinhua later gave 43 dead and 519 missing. |
This is a consular event as well as a national one
Roughly 600 to 644 of those missing on the Nepal side are foreign nationals, drawn from more than 25 countries. Syabrubesi is the road head for the Langtang trek, and late August sits at the front edge of the autumn trekking season.
India
105–177
United States
63–65
Ukraine
53
Malaysia
51
Australia
34–35
United Kingdom
33
Canada
24–25
South Korea
9
Nationals of more than 25 countries are among the missing, including Japan, Germany, France, Russia, Spain, Ireland, the Netherlands and South Africa. Figures differ between Nepali authorities, embassies and wire agencies, and the ranges above reflect that. Separately, 44 Nepal Army personnel, 26–28 Nepal Police officers, 9–13 Armed Police Force personnel and customs and immigration staff are unaccounted for.
Who said what, and who sent what
India's ten tonnes landed the same day. The distinction worth watching over the coming weeks is between condolence and disbursement.
Countries
India
10 tonnes of relief suppliesFlew ten tonnes of humanitarian assistance and disaster relief supplies on 26 August, the first foreign aid to arrive. Prime Minister Modi spoke directly with Prime Minister Balen Shah and said India was ready to provide all possible humanitarian assistance. India also has the largest number of nationals missing.
Source ↗China
Emergency supplies and cashCoordinated emergency supplies and cash assistance to Nepal, announced by the Chinese Ambassador. On its own side of the border Tibet mobilised roughly 800 emergency workers, 150 vehicles, sniffer dogs and speedboats. Xi Jinping issued directives calling for continued search and improved disaster monitoring.
Source ↗United States
US$500,000 + disaster response advisorThe State Department offered condolences, pledged assistance for emergency shelter, relief items, water, sanitation and hygiene, and said it would send a disaster response advisor. Secretary of State Marco Rubio offered condolences.
Source ↗United Kingdom
£5 millionPledged support for the Nepalese government and for British nationals in the affected area. The Foreign Secretary spoke with Nepal's foreign minister, expressed solidarity and offered financial, search-and-rescue and other assistance. 33 British nationals are among the missing.
Source ↗Australia
The Prime Minister said officials were urgently working to confirm the welfare of Australians in the area, liaising with local authorities and tour operators. DFAT announced assistance for flood-affected communities. 34 Australians are among the missing.
Source ↗Canada
The Prime Minister offered condolences and pledged support for the government's response. 24 Canadians are among the missing.
Source ↗Britain, Australia, Finland, Norway, France, Switzerland and the EU
Issued a joint statement urging those in affected areas to follow official safety advisories and the direction of local authorities.
Source ↗Multilateral, NGO & INGO
European Union
Copernicus satellite mapping + relief supportPledged support for relief efforts and activated the Copernicus Emergency Management Service, which maps disaster zones from satellite imagery to help authorities assess damage and coordinate rescue.
Source ↗United Nations
The Secretary-General said UN teams and partners were sending supplies and personnel to support the government-led response. UNICEF and other agencies began emergency operations.
Source ↗IFRC
CHF 1 million (about US$1.2m)Released emergency funding from its Disaster Response Emergency Fund to support Nepal Red Cross Society relief operations and damage assessment. NRCS is among the most active responders on the ground.
Source ↗ICIMOD
Provided the technical assessment tracing the surge to a rock-and-ice failure on the north face of Langtang Lirung, inside Nepal, falling into the Lhende Khola on the border. ICIMOD had documented the 2025 supraglacial lake expansion on the same river system.
Source ↗International Charter on Space and Major Disasters
Activated to provide satellite coverage of the affected corridor for damage assessment.
Source ↗“The acceleration of these types of events is completely unprecedented in the Hindu Kush Himalayan region.”
“Such surprises could be intensified in the coming days due to global warming.”
“United Nations teams and partners were sending supplies and personnel to support the Nepal government-led response.”
Recovery is measured in years here, and always has been
What “rebuilt” has actually meant in Nepal
The nearest precedent is Melamchi: a cascading Himalayan flood that destroyed the headworks of a scheme three decades in the making.
7 years for one headworks, with total economic impact estimated at up to US$500 million. Rasuwa lost fourteen hydropower facilities, a customs corridor, roughly 40 km of road and at least 19 bridges. Anyone offering a timeline in months is not describing Nepal.
If you are about to send money, read this first.
The government's own published account list is circulating with transcription errors, and fraudulent appeals reliably appear within 48 to 72 hours of a disaster. There is a safe way to give, and it takes one click, not a bank transfer typed from a forwarded message.
Bhote Koshi flood: common questions
What caused the Bhote Koshi flood of 26 August 2026?+
A slab of rock and glacier ice broke away at roughly 5,200 m from the north face of Langtang Lirung, a 7,227 m peak in Rasuwa inside Langtang National Park, and fell about 1,200 m into the Lhende Khola, the stream that marks the Nepal-China border. The surge ran down the Lhende and hit Rasuwagadhi and China's Gyirong Port together where it meets the Bhote Koshi, then carried on down the valley. The trigger point was in Nepal. USGS reclassified the initial magnitude 4.4 seismic reading as a landslide signal of Ms 5.2. ICIMOD provided the technical assessment.
How many people died in the Bhote Koshi flood?+
As of 18 September 2026, 9:00 am NPT, the official count (NDRRMA, via The Kathmandu Post) stood at 1,410 dead in Nepal, with 6,145 people still missing. Nepal Police had put the injured at 5,135 on 3 September. Chinese state media reported 43 dead and 519 missing on the Tibetan side. The Nepal toll rose from 31 on the first morning to over 1,000 within a week, as bodies were recovered as far downstream as Chitwan and Nawalparasi and across the border in India.
Was there any warning before the flood?+
Not in time. The Flood Forecasting Division sent SMS alerts to about 679,000 people in four districts at 9:15 to 9:16 am, roughly ten minutes after the surge had entered the Bhote Koshi, so there was no warning for Rasuwagadhi or Timure. Rasuwa's Chief District Officer said the flood struck without warning. The slope that failed was on Nepali soil, inside a national park, and nothing was watching it. The gap in monitoring small mountain tributaries was identified after the July 2025 flood on the same river and had not been closed.
Has this happened before on the Bhote Koshi?+
Yes, thirteen months earlier. On 10 July 2025 a supraglacial lake on the Purugu Glacier in Tibet, at 5,150 m and 36 km upstream of Rasuwagadhi, burst and flooded the same river, killing 9 with 19 missing and destroying the Nepal-China Friendship Bridge. At that time Nepal had two functioning glacial-lake monitoring systems against 21 identified dangerous lakes, and the Bhotekoshi basin was unmonitored.
How much hydropower was lost?+
The Nepal Electricity Authority reported 14 damaged hydropower and transmission facilities totalling about 748 MW: nine operating plants of 354 MW and five under construction of 394 MW. The named projects include the 216 MW Upper Trishuli-1, 120 MW Rasuwa Bhotekoshi, 111 MW Rasuwagadhi, 78 MW Sanjen Khola and 22 MW Chilime.
How long will recovery take?+
Years, not months. The nearest Nepali precedent is the 2021 Melamchi flood, which destroyed the headworks of the Melamchi Water Supply Project: reconstruction was hoped to begin in 2025 with completion targeted for 2028, roughly seven years, at an estimated total economic impact of up to US$500 million. Rasuwa lost more infrastructure than Melamchi did.
How can I donate safely to the flood relief effort?+
Use the Government of Nepal's official Prime Minister's Disaster Relief Fund portal at pmdrf.nchl.com.np, which takes card, NepalPay QR, connectIPS and wallets without requiring you to type an account number, or the Nepal Red Cross Society portal. Do not use bank account digits forwarded in a message: the government's published account list is circulating with transcription errors, and fraudulent appeals typically surface within 48 to 72 hours of a disaster.
Sources & data note
This is a mass-casualty event whose count is still rising. Nepal's confirmed death toll was reported at 31, then 95, 165, 175 and over 350 within the first 36 hours, and passed 1,000 within a week as bodies were recovered downstream. The headline toll on this page is the official count (NDRRMA, via The Kathmandu Post) as of 18 September 2026, 9:00 am NPT; NDRRMA's BIPAD portal does not consolidate this event, so there is no official machine-readable feed and the figure is updated by hand from primary reports. Every figure carries the outlet that published it and the time it was reported true. Amarnepal does not have reporters in Rasuwa; nothing here is independently verified on the ground. For the latest count, follow Nepal Police, the Kathmandu Post, Setopati and Onlinekhabar directly.
- Kyirong–Rasuwa flood 2026: frequently asked questionsICIMOD ↗
- What triggered the Rasuwa flood? Scientists piece together a complex chain of eventsThe Kathmandu Post ↗
- Nepal–Tibet floods: what happened, what caused them and who is missingAl Jazeera ↗
- At least 1,500 missing after deadly Nepal–Tibet floodsNPR ↗
- Hundreds killed in Nepal flood as fears grow of secondary disasterCNN ↗
- Bhote Koshi floods: death toll rises to 95, hundreds missingNepalnews ↗
- Supraglacial lake outburst in Tibet caused Bhotekoshi flooding (July 2025)The Kathmandu Post ↗
- Nepal floods affect hydropower projects in Rasuwa and NuwakotInternational Water Power ↗
- Rasuwa floods damage six hydropower and transmission facilitiesKhabarhub ↗
- How people can help Nepal's flood-affected communitiesThe Kathmandu Post ↗
- IFRC releases emergency funds as flash floods leave communities isolatedIFRC ↗
- Rasuwa Glacial Flood Situation Report (July 2025)NDRRMA / DPNet Nepal ↗
- Rasuwa Flood: a transboundary wake-up callNew Spotlight Magazine ↗
- 2026 China–Nepal floodsWikipedia ↗