Second wave threat looms over Nepal after deadly flash floods

A fresh flash flood threat is looming over Nepal after a devastating deluge in Rasuwa district, with a massive natural blockage still holding back water and debris upstream near the Nepal-China border, the International Centre for Integrated Mountain Development (ICIMOD) has warned.

The latest disaster struck the Bhote Koshi basin on August 26. Water levels began rising rapidly at around 9am, sending huge volumes of water, sediment and rocks downstream through the Bhote Koshi and Trishuli rivers. Within just 30 minutes, the Trishuli River rose by about nine metres at Galchhi and nearly seven metres at Malekhu.

Kyungang Zhang, head of ICIMOD’s Climate and Environmental Risks Division, said the area, already badly affected by last year’s floods, was again facing significant danger. An ice avalanche in the Lende Khola has been identified as a possible trigger, although the cause has yet to be confirmed.

Zhang warned that the blockage upstream on the Chinese side could give way at any time, unleashing another surge of water and debris. Authorities have ordered the evacuation of people from the Gyirong port area as a precaution.

Downstream areas of Nuwakot and Dhading districts are also being closely monitored. Scientists are analysing satellite imagery, seismic data and river-flow information to assess the stability of the blockage. Despite the ongoing rescue operation, communities along the Bhote Koshi and Trishuli rivers remain at risk.

Shashwat Sanyal, an ICIMOD disaster risk reduction specialist, said the Lende Khola area has experienced two floods in the past 14 months, highlighting how even small changes in the Himalayan cryosphere can trigger devastating floods within hours.

ICIMOD senior cryosphere specialist Mohammad Faruk Azam called for stronger cross-border coordination among Himalayan countries to deal with such disasters. He warned that cryosphere-related hazards are becoming increasingly severe and developing so rapidly that conventional disaster preparedness systems may struggle to respond in time.

Meanwhile, Nepal’s death toll from the floods and landslides has risen to 162, while 403 tourists remain missing, including 341 foreign nationals. Authorities fear the toll could rise further as rescue and search operations continue.

According to the latest Nepal Police figures, 64 bodies have been recovered from downstream areas of Chitwan district and another 26 from Nawalparasi East. At least 28 police personnel are among those reported missing.