What we know so far about the damage caused by Budhi Gandaki floods

A flash flood struck the Budhi Gandaki river in Gorkha early Sunday. It damaged homes, bridges, settlements, and infrastructure in Chumnubri and Dharche rural municipalities. The event disrupted travel and forced residents and tourists toward safer places. Authorities were still assessing the full damage and had not confirmed deaths or injuries.

More than 10 houses in Salleri, Paiyun, and Jagat Bagar were swept away. Two suspension footbridges and several other bridges were destroyed, including the motorable iron bridge at Soti. Floodwater also entered homes in Machhakhola, while houses in Salleri were considered at risk. The flood reached the Budhi Gandaki hydropower project in Salleri, Chumnubri-3.

Its construction camp and some equipment were swept away. Four people from a shed beside the Ungilung river were reported missing. Local officials and police used loudspeakers to tell riverbank residents to move. The cause and final damage assessment remained unresolved.

A flash flood is a sudden, fast-moving rise of water that can reach communities with very little warning. It may follow intense rainfall, a landslide, or the sudden release of water held behind a blockage. A slower-rising river flood usually builds over a longer period. That gives people more time to monitor water levels, protect property, and leave.

The Budhi Gandaki event had several flash-flood features. Residents and tourists heard loud sounds from the Ugyulung and Syar rivers around 4am. Water levels then continued to fluctuate. Authorities suspected that a landslide may have blocked the Syar river or another river near Ungilung, although the exact cause was not established.

The sudden danger explains the urgent warnings in riverbank settlements. Houses, bridges, and construction facilities were damaged before a full response could be organised. The report does not identify the rainfall conditions behind the flood.

The reported damage is spread across several settlements, so the article does not provide one final house total. More than 10 houses in Salleri, Paiyun, and Jagat Bagar were swept away. Five to seven houses and five to seven temporary structures in lower Machhakhola were flooded, with some houses reportedly swept away. Around 20 to 22 houses in Salleri were at risk.

The article specifically reports five bridges affected: two suspension footbridges, the Soti motorable iron bridge, the Nyakchet-Philim Bazar bridge, and the Gorkha-Dhading bridge at Arughat. One additional house was swept away in Sirdibas, while another was flooded. Four people living beside the Ungilung river were reported missing.

The Budhi Gandaki hydropower project also lost its construction camp and some equipment. These figures are preliminary. Authorities had not confirmed deaths or injuries and were still collecting details.

A landslide blocking a river can act like an unstable natural dam. Water keeps arriving from upstream, but the blockage prevents normal flow. The water level and pressure then rise behind the debris. This can create a dangerous reservoir even when people downstream do not yet see unusually high water.

If the blockage collapses, water is released in a sudden wave. The surge can carry soil, rocks, trees, and broken landslide material. That moving mixture can scour riverbanks, destroy bridges, sweep away houses, and inundate settlements. It can also make water levels rise and fall sharply as the blockage forms, shifts, or breaks.

Authorities suspected a landslide had blocked the Syar river between Lokpa and Chumling. They also considered a blockage near the Ungilung river in Chumchet. The article does not establish which explanation is correct. Officials were still collecting evidence and assessing the damage.

The report shows several sources of vulnerability. Homes and temporary structures stood beside the Budhi Gandaki and Ungilung rivers, placing them directly in the path of rising water. Communities also depended on suspension bridges and motorable bridges for movement. When those crossings failed, residents faced isolation as well as flood damage.

The danger was especially immediate because authorities suspected landslides near Syar and Ungilung rivers. A landslide can obstruct a river and then release water suddenly, leaving little time to respond. The flood swept away homes in Jagat, Ghattikhola, and other settlements, while water entered houses in Machhakhola.

The article does not provide a formal geographic analysis of why these municipalities are vulnerable. It does show remote riverbank communities, numerous bridges, and a hydropower construction site exposed to the same river system. Officials moved residents to safer places and continued checking the damage.

When floods threaten roads and bridges, warnings can reach people through local networks rather than normal transport routes. In this event, local authorities and police used loudspeakers to warn residents living along the river. Residents and tourists also began fleeing after hearing loud sounds from the rivers around 4am.

Officials moved people from Arughat Bazar’s riverbank to safer locations because the Budhi Gandaki remained a further flooding risk. Similar warnings were issued in Chumnubri, where homes had already been swept away or inundated. These actions depended on people hearing the warnings and moving away from exposed riverbanks before conditions worsened.

The article does not describe a detailed evacuation plan, shelters, transport system, or communication network. It records the measures used during this emergency: loudspeaker warnings, police involvement, local authority coordination, and movement to safer places. Continued bridge damage could make later evacuations more difficult.

Hydropower uses moving water to generate electricity. Water is directed from a river or reservoir toward turbines, often through a channel, tunnel, or pipe. The water’s elevation creates pressure, while its flow turns the turbine. A generator connected to the turbine then produces electricity. Greater flow or height can provide more generating potential.

The Budhi Gandaki project is described as a 341-megawatt semi-reservoir-type project under construction. Its site in Salleri, Chumnubri-3, was exposed when floodwater reached the river corridor. The construction camp and some equipment were swept away, showing how unfinished facilities can be vulnerable before a project is operating.

Construction sites need camps, machinery, materials, and temporary structures near the work area. Floodwater can damage or carry away these assets, even if the completed power plant is designed for river conditions. The article does not describe the project’s engineering design or planned flood protections.