Kathmandu, September 1 — Floods and mudflows along Nepal’s Bhote Koshi–Trishuli river system have left an estimated 2.2 million tonnes of debris across the affected areas, according to a preliminary assessment by the United Nations Development Programme (UNDP).
The flash floods, reportedly triggered by a glacial collapse on August 26, swept water, mud and rocks through communities in the affected districts. Nepal has reported more than 1,000 deaths, while over 4,000 people are reported missing. A total of 10,451 people have been rescued so far, according to the UNDP assessment.
The disaster has also caused significant damage to the country’s energy infrastructure. Eleven hydropower stations and one solar power plant, with a combined capacity of 431.1 megawatts, have stopped operating. Another 15 power projects under construction, with a planned capacity of 470 megawatts, have also been damaged.
The floods have disproportionately affected communities that were already among the most vulnerable in Nepal. Around three out of every four affected people were living in areas where communities already faced greater challenges in livelihoods, access to basic services and living conditions.
“This is a devastating disaster for communities along the Trishuli corridor. Families have lost loved ones, homes and livelihoods, while entire communities are struggling to reconnect with essential services and one another,” said Kyoko Yokosuka, UNDP Resident Representative in Nepal.
“The scale of destruction is immense, and as the immediate response continues, we must make sure that recovery reaches the people who have been hit hardest and helps them rebuild safely and with greater resilience,” she said.
Government figures show that 84,270 people have been affected across 17 municipalities in six districts. Most of the affected municipalities are rural and located in Nepal’s hill regions, where 67.4 percent of people depend on agriculture for their livelihoods.
Damage to crops, livestock and farmland could have a lasting impact on household incomes and food security. The timing of the disaster has further compounded the impact on farming communities, as Nepal’s main monsoon planting season runs from June through September.
The UNDP assessment estimates that around 556,200 tonnes of the debris comes from buildings, based on satellite assessments covering damage to 2,359 buildings. The figure is expected to increase as additional damage is identified.
The debris includes collapsed buildings, household belongings, vegetation, rocks and sediment. For rescue teams and affected families, the debris represents more than the physical scale of destruction, as people may remain trapped or missing beneath collapsed structures and piles of mud and debris, making rescue operations difficult and dangerous.
UNDP conducted the preliminary assessment using satellite-based building damage assessments from Copernicus EMS and SERTIT, combined with other available data and locally adapted engineering estimates. The findings will be updated as more information becomes available.
The scale of the debris highlights the enormous challenge facing affected communities as they clear homes, roads and public spaces and begin the process of rebuilding. Damage to hydropower and other energy infrastructure has also disrupted electricity supplies and slowed the restoration of essential services.
