Glacial lake outburst in Bhutan prompts flood alerts in West Bengal and Assam

A glacial lake outburst flood was reported at Shintaphu Lake in Bhutan's Gasa district, prompting concerns about a rapid surge of water into the Sankosh River, which flows into India. The Indian government issued a special advisory for parts of West Bengal and Assam, warning that water levels could rise sharply along the river.

The outburst was detected on Thursday evening near Wakila Mountain in Layo Gewog. Sirens sounded in the immediate area and residents were moved to safer ground. Shintaphu Lake is one of 17 glacial lakes in Bhutan considered potentially dangerous. An official from the National Centre for Hydrology and Meteorology said a monitoring station at Taktsimakhang had not recorded an alert at the time of the report, and the full extent of the outburst remained unclear.

India's advisory highlighted the risk of a flash flood in the upper Punatsangchhu River, which becomes the Sankosh after crossing the border. Alerts were sent to districts in North Bengal, including the Darjeeling hills, Alipurduar and Jalpaiguri, as well as Assam's Dhubri district. National Disaster Response Force and State Disaster Response Force teams were deployed to Tufanganj and Boxirhat in West Bengal's Cooch Behar district, near the border.

"A surge of water could reach the river in Kumargram within the next one to one-and-a-half hours," West Bengal Forest Minister and Kumargram MLA Manoj Kumar Oraon said in a video message, urging residents to evacuate and cooperate with authorities.

Officials expect floodwater to reach the India-Bhutan border within six to eight hours and have asked local authorities to monitor the situation closely and take precautionary measures. The Sankosh River supports riverside communities, livestock, farmland and infrastructure, making a sudden rise in water level a significant threat.

The situation continues to be assessed as authorities track the movement of floodwater downstream.