Nepal Floods
Overview
Nepal Floods (네팔 대홍수) refers to the large-scale floods and landslide disasters that recur across Nepal every South Asian monsoon season. In particular, the record rainfall that struck the Kathmandu Valley from September 26 to 28, 2024, is considered the worst flood in recorded history, killing more than 200 people nationwide and displacing tens of thousands. As Himalayan glacial melt, rapid urbanization, and indiscriminate hillside development compound one another, the scale of damage has been growing year by year.
Main content
Geographic and climatic background
Nepal lies on the southern slopes of the Himalayan range and stretches from the Terai plains at roughly 60 m above sea level to peaks exceeding 8,000 m, giving it the world's steepest elevation gradient. About 80% of annual precipitation is concentrated in the June–September southwest monsoon season, with rain often falling in intense bursts over short periods. Because of steep terrain, fragile soils, and landslide-prone geological structures, heavy downpours cause rivers to overflow and hillsides to collapse within moments. The Kathmandu Valley is a basin that drains poorly, and urbanization has increased impervious surfaces, making it structurally highly vulnerable to inundation. Major rivers include the Bagmati, Bishnumati, and Melamchi.
September 2024 Kathmandu floods
From September 26 to 28, 2024, heavy rain was concentrated on the Kathmandu Valley for three days. At some stations 24-hour rainfall exceeded 240 mm and reached more than 320 mm at maximum, breaking records dating back to 1970. The Bagmati River rose far above the warning level and overflowed its banks, inundating large areas of the urban centers of Kathmandu, Lalitpur, and Bhaktapur. Many flights at Tribhuvan International Airport were cancelled or delayed, and major highways such as the Prithvi Highway were buried by landslides, delaying the transport of relief supplies. Nationwide deaths reached around 220, with more than 100 missing; thousands of residents were rescued and tens of thousands displaced. Schools, hospitals, and water and power facilities were also inundated and rendered inoperable.
Recurring floods and glacial lake outburst floods (GLOF)
Nepal's flood disasters are not confined to a single event but recur. In June 2021, flooding in the upper Melamchi River destroyed villages, roads, and a hydropower plant, and in August 2023 landslides in western regions also caused heavy casualties. In August 2024, a glacial lake outburst flood (GLOF) occurred at Thame village in the Everest region of Khumbu, sweeping away homes and bridges. The direct cause is identified as Himalayan glaciers melting, causing glacial lakes to multiply rapidly and water levels to rise.
Analysis of causes
First, climate change. The Himalaya region is warming faster than the global average, glacial area is shrinking, and the number of glacial lakes is estimated to have grown to more than 2,000. Second, expanding monsoon variability. The frequency and intensity of short, intense cloudburst-type rainfall is increasing more than total precipitation. Third, urbanization. As the population of the Kathmandu Valley surged, riverbanks and wetlands were filled with buildings, and drainage and sewage systems failed to keep pace. Fourth, hillside development. Road construction, quarrying, and logging have disturbed slopes, increasing landslide risk.
Damage, recovery, and international response
The Nepalese government mobilized the army, police, and disaster management authority for rescue and relief operations, and international organizations such as UNDP, WFP, and the International Federation of Red Cross and Red Crescent Societies, along with neighboring countries including India and China, provided relief supplies and equipment. However, because mountainous areas are hard to reach and recovery budgets are insufficient, temporary housing and livelihood support often drag on. As core infrastructure such as roads, bridges, and hydropower is repeatedly destroyed, regional economic recovery proceeds slowly.
Latest trends
In 2024–2025, Nepal and the international community are shifting policy toward disaster prevention. Led by the International Centre for Integrated Mountain Development (ICIMOD), glacial lake monitoring and early warning systems have been expanded, and additional hydrological stations and automatic rainfall observation networks have been installed. In the Kathmandu Valley, nature-based solutions such as river restoration, drainage expansion, and wetland restoration are under discussion. In international climate negotiations, there is a growing call to use the Loss and Damage Fund to support disaster recovery in developing countries. Flood and landslide damage continued in the 2025 monsoon season as well, and calls to strengthen urban planning and land-use regulation are being raised repeatedly. Humanitarian assistance and cooperation on disaster response technology from the international community, including South Korea, are also expanding.
Related topics
- [[Monsoon]]
- [[Climate change]]
- [[Glacial lake outburst flood]]
- [[Kathmandu]]
- [[Nepal]]