Archive · 27 Aug 2026
Scientists Warn Nepal Flood Surge After Upstream Blockage
Scientists think a large pile of ice and rocks may have fallen high in Nepal’s mountains.
This may have blocked water upstream.
If the blockage breaks or shifts, a sudden flood could move downstream.
Water in the Trishuli River rose very quickly at two locations.
It went up as much as nine metres at Galchchi in only 30 minutes.
At Malekhu, it rose seven metres in about the same time.
These fast changes show that a lot of water may have moved suddenly.
Scientists are warning that another flood surge could happen.
Scientists warn that an upstream blockage could trigger another major flood surge in Nepal.
A leading hypothesis suggests a large ice-rock avalanche occurred high in the mountains.
Water levels in the Trishuli River at Galchchi rose by up to nine metres within 30 minutes.
Levels at Malekhu increased by seven metres over a similar period.
The rapid rises highlight the potentially large scale of the mountain event.
- Who
- Scientists and hydrological observers are warning about the potential surge.
- What
- A possible upstream blockage, thought to have been caused by an ice-rock avalanche, could trigger a fresh flood surge.
- When
- The timing of the possible fresh surge is not specified; the reported river-level rises occurred within about 30 minutes.
- Where
- High in Nepal’s mountains and downstream along the Trishuli River at Galchchi and Malekhu.
- Why
- A blockage caused by falling ice and rock could suddenly release or redirect a large volume of water.
- Country
- Nepal
- Suspected event
- A large ice-rock avalanche high in the mountains
- Potential hazard
- A fresh flood surge caused by an upstream blockage
- River
- Trishuli River
- Galchchi rise
- Up to nine metres within 30 minutes
- Malekhu rise
- Seven metres over a similar period
- Evidence
- Hydrological measurements showing rapid water-level increases