Nepal Flood 2026 River Corridor, Bhote Koshi and Trishuli

OpenStreetMap and Overture Maps vector layers for the area flooded in the 2026 Bhote Koshi and Trishuli flood in Nepal, and the ground immediately around it. The area of interest is the observed flood extent of 27 August 2026 widened by 200 metres. The extent itself was mapped from drone, Landsat, PlanetScope and Sentinel imagery and is published here as its own resource, so the water line can be separated from the margin around it. That margin brings in buildings and roads beside the water, so a feature being in this dataset is not evidence that it was flooded or damaged. Clip to the Flood Extent resource when you need figures for the water itself. The area follows the river from Rasuwagadhi to the Narayani confluence, across Bagmati and Gandaki Provinces and the districts of Rasuwa, Nuwakot, Dhading, Gorkha and Chitawan. Every layer holds what is standing and what has been lost, so buildings and roads do not vanish from a download once mappers record them as destroyed. `status` says Standing, Damaged or Destroyed, and the Destroyed and Damaged Features layer gathers everything marked destroyed or damaged in one place. Layers are rebuilt straight from OpenStreetMap through the day, so they carry volunteer work as it lands. Buildings, schools, health facilities and points of interest also come in an Overture version, which fuses Microsoft, Google and OpenStreetMap and reaches ground volunteers have not mapped yet. Overture follows its own release cycle and will not show mapping done during this response, so for damage work prefer the OpenStreetMap layers and use Overture where their coverage is thin. Mapping task boundaries from the Tasking Manager campaign show where volunteers are being asked to map. The bridge damage assessment is reported from the ground by volunteers and lists road bridges with their condition after the flood, deck length where measured, and administrative codes from the same boundaries as the other layers. For the wider 1 km river corridor under assessment, use Nepal Flood 2026 River Corridor. AI-scored building damage from post-event imagery is published separately as Nepal Flood 2026: fAIr Damage Assessment. Subscribe to the dataset for updates as mapping progresses. - Source: OpenStreetMap, Overture Maps, NAXA and volunteer field reports - Part of HOT disaster response exports on HDX by HOT

Part of the Humanitarian OpenStreetMap Team response activation for the 26 August 2026 Bhote Koshi and Trishuli flash flood in Nepal. AI-scored building damage per OpenStreetMap footprint across the upper Trishuli and Bhote Koshi corridor, from Rasuwagadhi to the Narayani confluence. Post imagery is a 26-scene Vantor open-data composite (2026-08-27 to 2026-09-08, roughly 0.4 m/px, about 9.8% cloud). Pre imagery is ESRI World Imagery. Building footprints come from OpenStreetMap and cover 20,367 features in the corridor; 8,421 fall inside the analyzed area and carry an AI damage class. Each feature carries `osm_id`, `osm_type`, `building`, a `damage` label (`no-visible-damage`, `minor-damage`, `major-damage`, `destroyed`) and a `damage_confidence`. Evaluated and validated against 3,896 OSM manually tagged affected buildings (3,185 destroyed + 711 damaged, 2026-09-12): destroyed precision 0.91, recall 0.78, F1 0.84; severe (major + destroyed) recall against manually tagged affected buildings 0.75. The reference layer is included in this dataset. Post-event imagery TMS: ``` https://titiler.hotosm.org/cog/tiles/WebMercatorQuad/{z}/{x}/{y}?url=https://production-raw-data-api.s3.amazonaws.com/ISO3/NPL/buildings/hot_flood_npl_buildings_damage_post.tif ``` For the wider corridor context, see Nepal Flood 2026 Flood Affected Area. - Source: OpenStreetMap, Vantor open data, ESRI World Imagery - Part of HOT disaster response exports on HDX by HOT

Water features across the area: rivers, streams, canals, lakes, ponds, and water bodies tagged with `waterway`, `water`, or `natural=water`. Useful for flood-risk modelling, watershed analysis, and environmental basemap context. Coverage reflects where volunteer mappers have been active. Urban areas are usually well represented, remote areas may be sparse. Cross-check critical decisions with local field knowledge. - Source: OpenStreetMap, a free, collaborative world map - Tags: waterway, water, natural - Part of the country exports on HDX by HOT

Overture building footprints and IHME population estimates in the identified impacted area from the 26 August flash flood in Nepal. - 37 sq km impacted - 4,977 intersecting Overture building footprints - IHME 2026 Population Estimate 10,203.8

satellite imagery by Planet, acquired 2026-05-26 to 2026-05-26, 300 cm per pixel, published on OpenAerialMap.

We have assessed *primary and secondary roads* for signs of road blockages in the *Rasuwa, Nuwakot and Kathmandu* regions in Nepal. **Brief Overview: 28/08/2026 Dataset** -We found 22 road blockage locations (19 of these locations were severely flooded) -The NH42 road was highly impacted by flooding, and parts of NH03, NH18 and F181 roads were affected by flooding. -The data is held in a point shapefile format in WGS 84 EPSG: 4326. *This dataset is derived from crowd sourcing. The next data release is planned for 11/09/2026.* You can find the Planetary Response Network: Nepal Flash Flooding 2026 project we ran here.