A glacial lake outburst flood reported at Lemthang in Bhutan has triggered high alerts across North Bengal and parts of Assam, with residents along the Sankosh River and its tributaries advised to move to safer locations as disaster response teams prepare for possible flooding.
The reported outburst sent water downstream through the Mo Chhu River towards the Sankosh River, prompting emergency preparedness measures in vulnerable areas of West Bengal and Assam. Authorities have urged residents in the Darjeeling hills, Terai and Dooars regions, as well as people living in vulnerable revenue circles of Assam’s Dhubri and Kokrajhar districts, to remain alert and follow official advisories.
Assam Chief Minister Himanta Biswa Sarma said the state government was monitoring the possible impact across vulnerable revenue circles in Dhubri and Kokrajhar. In a post on X, he said state authorities were coordinating with the National Disaster Response Force and other agencies, while asking residents to cooperate with local officials.
“Residents are requested to stay alert, follow official updates and cooperate with local officials,” Sarma said, adding that response teams were ready to act if required.
BJP MP from Darjeeling Raju Bista also issued an alert, saying residents in the catchment areas of the Sankosh River and connected tributaries should immediately move to a safe distance. His post described the water as flowing through the Mofu River towards the Sunkosh River. The differing river names in the public alerts reflect the descriptions carried by the authorities and political representatives cited in the report; residents have been advised to rely on official local instructions.
State Minister Nisith Pramanik said the water was expected to reach the plains within five to six hours of the report, raising concerns about flooding in the region. He said the State Disaster Management Team had been activated, the NDRF notified and disaster management volunteers instructed to remain present on site.
In Alipurduar, Superintendent of Police Amit Kumar Shaw said the administration was coordinating with Bhutanese authorities, district officials and disaster response agencies. The SDRF was present, an NDRF team was on its way and a Civil Defence team had been deployed, he said.
Shaw said approximately 4,000 to 5,000 people had been moved to shelters using school buildings as relief centres, while more than 6,000 others had been relocated to safer areas. The administration had arranged dry food, drinking water and toilet facilities at the relief locations, he said.
A glacial lake outburst flood, or GLOF, occurs when a natural dam holding back a glacial lake fails or is breached, releasing a large volume of water downstream. Such events can quickly affect settlements and transport links in river catchments, making coordination across borders and districts critical during the response.
Shaw said the intensity of the water flow had decreased slightly according to the latest information available, but authorities remained on high alert. Police, district administration and block-level officials were continuing to monitor developments and prepare for any further emergency.
