A massive flash flood struck Nepal on August 26, 2026, after a sudden surge from the Tibet side affected the Bhote Koshi–Trishuli river system, killing at least 157 people.
Experts said an ice-rock avalanche/glacial collapse at high altitude likely triggered the flood, sending water, ice, rocks and debris downstream.
The flood caused a rapid rise in the Bhote Koshi and Trishuli Rivers, severely affecting Rasuwa, Nuwakot and Dhading districts.
The Bhote Koshi is part of the Koshi River system, while the Trishuli flows into the Narayani River.
Increased flows were expected in the Koshi and Narayani river basins, while a possible flood wave in the Gandak River led to alerts in Bihar.
The disaster damaged 19 motorable bridges and about 40 km of roads, besides affecting settlements and hydropower infrastructure.