Kathmandu. The International Centre for Mountain Development (ICIMOD) has described two major floods in Nepal in a span of 24 hours as “unprecedented incidents”.
Geological and meteorological experts of ICIMOD have concluded that the floods in Rasuwa and Upper Mustang on Tuesday were a glacial event that drained from the ‘Supraglacial’ lake.
According to ICIMOD, experts believe that a small-sized ice lake was formed initially around the end of 2024 (December) but by the time it reached June, it had turned into a huge glacial lake.
Scientists at ISIMOD, which monitors floods and glacial lakes, called it TAG_OPEN_a_14 an “unprecedented event” }.
The Bhotekoshi River, which flows through The Northern Border rasuwa via Tibet of China, was flooded at around 3 am on Tuesday. The floods have not only washed away the Miteri bridge on the Nepal-China border, but also killed nine people, including security personnel. 20 people are missing.
On Tuesday evening, four bridges and roads were damaged due to heavy floods from Upper Mustang. The Chumjung rivulet, which flows through Lomanthang rural municipality, has been flooded. However, there was no loss of life due to the safe rescue from the flood-affected areas.
Isimod experts, based on an analysis of satellite images from 2020, have concluded that the floods in Rasuwa and Upper Mustang have been caused by the rupture of the lake formed on the upper surface of the glacier covered with piles of stones.
“The supraglacial lake near the Nepal-China border was formed as a small pond in December 2024 and has been found to have widened significantly in June 2025 and burst on Monday,” icimod said in a statement. ’
