NESRA Flood Situation Brief #02
Rasuwa / Bhotekoshi–Trishuli Flood · 27 August 2026
Download Situation Brief #02 (PDF) Return to live incident pageThe DHM River Watch display reviewed at 14:38 NPT listed Trishuli at Furke as below warning level and steady. This is a station-specific reading—not an all-clear for damaged or unmonitored upstream reaches. Check DHM and NDRRMA for current instructions.
1. Situation overview
A major flash-flood and debris-flow event entered Nepal through the Lhende–Bhotekoshi corridor on 26 August and propagated through the Trishuli–Narayani system. USGS analysis indicates that the recorded seismic signal was produced by glacial collapse and debris flow rather than an earthquake. ICIMOD and Nepal disaster-management reporting point to an ice–rock avalanche; temporary damming and release remain under assessment.
2. Current official risk status
DHM’s current station display is visually dominant over earlier historical warnings. Earlier reports documented damaged gauges and an upstream blockage that was not fully resolved at publication time; present conditions must therefore be checked directly with DHM and NDRRMA. DHM flood information: 1155, option 2.
3. Geographic impact
| Area | Current assessment | Basis |
|---|---|---|
| Upper corridor | Rasuwagadhi, Timure and Syabrubesi severely affected; individual-structure totals remain incomplete. | Authorities and media |
| Middle corridor | Betrawati, Trishuli and nearby settlements affected as the debris-rich flood moved downstream. | Probable |
| Downstream | Flood wave traced through Muglin and Devghat; DHM recorded a Devghat peak of 6.57 m at 16:00 NPT on 26 Aug. | DHM technical report |
4. Access and connectivity
The approximately 42 km Betrawati–Rasuwagadhi road has severe physical damage and reported bridge losses. Safe end-to-end passability has not been authoritatively confirmed. Physical damage must not be interpreted as an official open/closed determination.
5. Critical infrastructure
Roads, bridges, telecommunications, hydropower facilities and river-monitoring infrastructure were affected. Syabrubesi and Betrawati gauges stopped transmitting; the Furke/Malekhu station and bridge were reported washed away. Project-level damage remains subject to authoritative engineering assessment.
6. Response activity and impact figures
More than 5,000 army and police personnel joined the response. The Nepali Army reported 125 people retrieved on Thursday, including 20 foreign nationals, while helicopters delivered tents, food and emergency supplies.
NDRRMA reported 165 bodies recovered and 823 people out of contact in the latest reviewed update. Status: PROVISIONAL. Cross-border totals and figures using different geographic scopes must not be added directly.
7. Earth Observation status
| Source | Availability | NESRA status |
|---|---|---|
| Copernicus EMSR927 | Rapid Mapping ongoing; 2 AOIs; 0 products displayed at review time. | External products pending |
| PlanetScope | 9 post-event scenes at about 3.8 m; 62–93% cloud and 2–14% clear area. | Available, cloud-limited |
| SkySat | 2 post-event collects from 27 Aug at about 0.8 m over Rasuwagadhi and Syabrubesi; about 50% cloud and 8% clear. | New focal imagery; review required |
| Sentinel-1 | Pre-event baseline from 24 Aug; suitable post-event assessment not published by NESRA. | Monitoring / pending |
| NESRA EO output | No NESRA satellite-derived flood extent published. | Publication control remains closed |
Method limitation: pre-event PlanetScope analytical data are surface reflectance while post-event analytical data are top-of-atmosphere radiance. Direct analytical band differencing is unsafe without atmospheric correction. SkySat covers two focal areas, not the full corridor.
8. Key information gaps
- Authoritative passability for each damaged road segment and bridge.
- Condition of upstream blockage or impoundment areas and residual secondary-hazard risk.
- Reconciled Nepal-specific casualty, missing-person and rescue totals.
- Engineering assessments for hydropower, telecommunications and public infrastructure.
- A suitable validated post-event radar assessment and any approved NESRA EO product.
9. Sources
- DHM River Watch and DHM technical situation report mirror.
- NDRRMA, Nepal Police and Nepal Tourism Board statements reported by Reuters and The Guardian.
- Planet Crisis Response STAC catalog, including 27 Aug SkySat additions; CC BY-NC 4.0.
- Copernicus Emergency Management Service EMSR927.
- ICIMOD scientific advisory.
- Independent Rasuwa flood bulletin, used as a source index; operational information should be verified with the originating authority.