- A flash flood in Nepal's Budhi Gandaki River left ten people missing and destroyed homes, bridges, and hydropower facilities in Gorkha district.
- Authorities suspect a landslide blocked a stream in Chumnubri Rural Municipality, triggering a sudden surge of water, mud, and debris downstream.
- Search and rescue operations are underway using helicopters and drones, though destroyed bridges and terrain hamper access to remote affected settlements.
- Seismologists believe reported ground tremors were likely caused by the massive landslide rather than an earthquake, following technical analysis of local signals.
Landslide suspected of triggering flash flood; rescue operations and damage assessments underway
Kathmandu, Nepal: A flash flood in the Budhi Gandaki River in northern Gorkha district on Sunday morning swept away houses, bridges and other infrastructure, leaving several people missing and disrupting transport and communication services in affected areas.
Preliminary reports put the number of missing people at up to 10, although the figure had yet to be confirmed by a consolidated official assessment. The flood damaged houses, livestock sheds, a school building, hydropower infrastructure and electricity and communication facilities.
Authorities suspect that a landslide blocked a stream in the upper reaches of Chumnubri Rural Municipality, causing water to accumulate before the blockage gave way. The resulting surge of water, mud and rocks is believed to have entered the Budhi Gandaki River and swept through settlements downstream.
However, the precise source of the flood and the circumstances that triggered it have yet to be established.
Search and rescue operations underway
Ten people were reported missing in Chumnubri Rural Municipality-6, although initial reports from different sources gave varying figures. Five of those reported missing were said to be residents of Chumchet who had been staying in sheep sheds near Ungilung Khola.
They were identified as Sonam Lama, 65; his wife, Lakpa Thorma Lama, 59; Som Bhuti Lama, 66; Karma Lama, 68; and Ten Dorje Lama, 41. Five additional people from the Dhaula area were also reported missing, but their identities and whereabouts had yet to be independently confirmed.
The flood reportedly swept away four sheep sheds and around 150 livestock.
Personnel from the Nepali Army and Nepal Police, assisted by local residents, were mobilised for search and rescue operations. Army helicopters were also used to evacuate people stranded in remote areas.
The difficult terrain and the destruction of bridges have hampered access to affected settlements, making it difficult to reach some areas by road.
Houses and bridges damaged
Several settlements in Chumnubri and Dharche rural municipalities were affected by the flood. Houses, animal sheds and temporary structures along the river were swept away, while mud and water entered other homes.
Areas including Nyakchet, Sirdibas, Salleri, Jagat and Ghattekhola in Chumnubri were among those affected. Settlements around Machhikhola in Dharche also reported damage.
The flood reportedly swept away the building of Bikas Basic School in Ghattekhola, Chumnubri-3, raising concerns about disruption to classes.
Preliminary reports also indicated damage to at least six bridges, including two motorable bridges and four suspension bridges. The affected structures included bridges connecting Nyakchet with Sirdibas and Machhikhola with Kerauja. Bridges in the Aarughat area were also reported damaged.
The destruction of bridges has disrupted local movement and could delay the delivery of relief supplies and the transportation of patients to health facilities.
Authorities have yet to publish a consolidated assessment of the number of houses and bridges damaged or destroyed.
Hydropower infrastructure affected
The flood also damaged infrastructure associated with hydropower projects in the district. Preliminary reports indicated damage to powerhouses, construction camps, bridges, equipment and other project facilities.
The powerhouse of a hydropower project in Salleri and nearby houses were reportedly affected. Structures associated with the Dovan Khola and Yaru Khola hydropower projects also sustained damage, according to initial reports.
The extent of the damage and its financial value have yet to be determined. Electricity poles and communication infrastructure were also damaged, potentially disrupting services in some areas.
Landslide suspected as the cause
Initial assessments suggest that a landslide blocked a stream in the upper reaches of Chumnubri before the accumulated water and debris surged downstream.
The Nepali Army reported a possible dry landslide in the Philim area of Chumnubri Rural Municipality-3. However, the exact location of the blockage and its relationship to the flood have yet to be conclusively established.
The National Disaster Risk Reduction and Management Authority (NDRRMA) sent a team equipped with drones to the upper reaches of the affected area to investigate the possible source of the flood.
Authorities are examining the landslide site, river conditions and surrounding terrain to determine what happened and assess the risk of further flooding.
Reported ground tremors under investigation
Some residents of northern Gorkha said they felt the ground shake before the flood. A seismic monitoring system operated by the US-based EarthScope Consortium also recorded a signal at Nepal's Kakani station.
The signal was reportedly recorded between 4:25 am and 4:30 am Nepal time on Sunday. However, the National Earthquake Monitoring and Research Centre reported no earthquake in Nepal during the preceding 24 hours.
Senior seismologist Dr. Mukunda Bhattarai said no earthquake had been recorded during that period.
NDRRMA chief executive Dr. Dharmaraj Upreti said the signal could have resulted from vibrations caused by a landslide. Geologist Dr. Lok Bijaya Adhikari also noted that landslides and falling rocks can generate ground vibrations.
The available information does not establish whether the recorded signal was directly related to the Budhi Gandaki flood. Seismic monitoring equipment can detect vibrations from several sources, including landslides and falling rocks, so the signal alone cannot confirm that an earthquake occurred.
Further technical analysis is needed to determine the source of the recorded vibrations.
Downstream communities warned
Authorities have urged residents in vulnerable settlements along the river to remain alert and move to safer locations if necessary.
The destruction of bridges and the isolation of remote settlements have complicated the emergency response. Search operations, evacuation, relief distribution and the collection of damage reports remain priorities.
The flood has also highlighted the need to identify areas where landslides could block rivers, strengthen river monitoring and improve early-warning systems for communities downstream.
Reconstruction costs remain uncertain
The Budhi Gandaki disaster comes as Nepal continues to deal with infrastructure damage caused by floods and landslides in other parts of the country.
Infrastructure Development Ministry Secretary Padma Kumar Mainali told a parliamentary special committee that disasters this year had caused an estimated Rs 227 billion in damage to infrastructure nationwide. An estimated Rs 63 billion would be required for initial reconstruction work.
The figures are preliminary nationwide estimates and do not represent the cost of the Budhi Gandaki flood alone. A separate assessment of the damage caused by Sunday's disaster has yet to be completed.
For now, authorities are focusing on locating the missing people, evacuating residents from vulnerable areas and assessing the damage. The final toll and the cause of the flood are expected to become clearer after field investigations and the consolidation of reports from the agencies involved.
