Nepal Floods: Scientists Warn of New Danger as Rivers Dammed by Debris

KATHMANDU — Rescue workers and residents in Nepal’s flood-hit valleys faced a fresh threat on Friday, as scientists warned that debris from the initial disaster had blocked rivers upstream, creating fragile dams that could burst at any moment. In the narrow upper valleys, the flood wave that struck on Wednesday rose above the tops of buildings and homes, sweeping away everything in its path. The full extent of the destruction remains unclear, but officials said the immediate priority is now preventing a second wave of inundation. The risk comes from natural dams formed by mud, rocks, and uprooted trees. These barriers are unstable. If they give way, water held behind them could rush downstream without warning, hitting areas already struggling to recover. Authorities are monitoring the blocked rivers closely. However, they warned that heavy rain could speed up the collapse of these fragile structures. Residents have been urged to stay alert and move to higher ground if they see water levels rising suddenly. The situation remains fluid. Emergency teams are working to reach isolated communities, but many roads and bridges are destroyed or underwater. The coming hours will be critical as scientists assess whether the natural dams will hold or release another surge of water.