Flash Flood Sweeps Away Dozens of Homes in Nepal's Gorkha

Updated October 14: A Landslide With the Force of a Small Quake

A preliminary assessment by Nepal's Department of Mines and Geology, shared by the National Disaster Risk Reduction and Management Authority and reported on October 14, found the October 11 landslide high in Gorkha district generated energy equivalent to a 3.5-magnitude earthquake. The finding gives a new measure of the force behind the flood that followed.

The slide began at about 4:20 a.m. in the upper reaches of the Ungdilung Khola, a tributary of the Budhi Gandaki River, in Chumnubri Rural Municipality near the China border, between Chamar Himal and Syerangi Himal. An avalanche started near 6,000 metres, with the landslide at about 5,500 metres. Snow, water and glacial debris blocked the river and then broke free repeatedly in a single day, and the largest flood surge was estimated at 20 to 25 metres high. At least five people remain missing, and hydropower projects, roads and bridges were destroyed.

Updated 14:35 UTC: Rescuers had brought out 321 people, including 12 foreigners, by Monday, according to Reuters, and the army rescue operation continued into Tuesday. More than 100 foreign trekkers are still stranded at points along the Manaslu Circuit, where the flood swept away trail sections and bridges. Bhuwan Raj Ojha, an official of the Manaslu Conservation Area Project, told Reuters the trekkers are sheltering in tea houses and restaurants along the route and are safe. Hikers who want to return will be helped out, and those who want to continue from safe points can do so, he said. There were still no confirmed fatalities in the latest reporting. Five villagers remain missing, three hydroelectric plants were damaged, and the river rose from about 2 meters to nearly 8.5 meters at one monitoring point, where a hydrological station was swept away. ICIMOD, reviewing preliminary accounts from Nepal authorities, assessed that a landslide dammed the Syar Khola tributary near Chumling and then breached. The Department of Hydrology and Meteorology recorded no rainfall in the upper catchment in the 24 hours before the flood. The original report follows.

KATHMANDU: A debris-laden flash flood tore through Nepal's Gorkha district early Sunday, sweeping away dozens of houses and bridges after a landslide dammed the Budhi Gandaki River and then burst.

The flood struck around 4 a.m., according to local officials, sending muddy water loaded with debris down the valley through Chumnubri Rural Municipality in the Manaslu region, roughly 100 kilometers west of Kathmandu. Villagers fled to higher ground in the dark, many carrying nothing.

"The flood came early in the morning, and we could not even take out our belongings," one local official told reporters.

What happened

Nepal's disaster authority, the NDRRMA, said a landslide between Lokpa and Chhumling blocked the Budhi Gandaki, creating a barrier that later gave way. The sudden release sent a wall of water downstream.

The authority learned of the flood at 6:20 a.m. and sent SMS warnings at 6:40, telling people to stay away from the river up to Trishuli Dobhan. But villagers upstream had already been phoning warnings down the valley for about an hour. One man, Sherap, told the Kathmandu Post that what he saw reminded him of the August Bhotekoshi flood. He did not wait for an official message.

The cause has not been formally confirmed. Residents suspect the Syar stream, a tributary between Lokpa and Chumling, was blocked and triggered the surge.

The damage

Counts vary as officials work from patchy reports, with roads cut and phone signal poor in the upper valley. The NDRRMA reported 45 houses completely destroyed and 27 partially damaged, along with two suspension bridges, two motorable bridges and three hydropower projects.

Bridges linking settlements across the mountainous terrain were destroyed, including the concrete bridge connecting Arughat in Gorkha with Dhading, the suspension bridge between Nyakchetat and Sirdibas, and the Machhikhola-Kerauja footbridge. A school in Ghattekhola was damaged.

Between five and ten people were missing, officials said, with the NDRRMA confirming five including two women. No deaths had been confirmed.

The rescue

By Sunday evening, 95 people had been rescued from settlements across Chumnubri using four helicopters, including an MI-17, alongside ground teams. The Nepal Army deployed 171 soldiers, with Nepal Police and the Armed Police Force also mobilized, and a rapid-response team was airlifted from Kathmandu.

October is peak trekking season on the Manaslu circuit, and the trail was full. More than 100 foreign tourists were stuck at Jagat, the gateway to the protected area, with 98 having entered on Saturday alone.

Why it matters

The disaster comes barely six weeks after devastating floods along the Bhotekoshi and Trishuli rivers on Aug. 26, which killed 1,455 people and left 5,285 missing, according to the NDRRMA. Nepal's mountains are growing more dangerous as climate shifts intensify monsoon extremes and destabilize slopes.

For the villages of the Budhi Gandaki valley, the immediate worry is shelter and the severed bridges that were their only links to markets, schools and clinics. Rebuilding will take months; the next monsoon surge could come far sooner.

Key numbers

• 45: houses completely destroyed, per the NDRRMA (27 more partially damaged)
• 5: people confirmed missing, including two women
• 95: people rescued by Sunday evening
• 100+: foreign trekkers stranded at Jagat
• 4: helicopters deployed in the rescue operation