Glacial lake overflow in Bhutan triggers flash flood alerts in India

The overflow of a glacial lake in Bhutan has damaged infrastructure in the Himalayan country and prompted flash flood warnings in northern districts of the Indian states of Assam and West Bengal.

Bhutan’s National Center for Hydrology and Meteorology (NCHM) reported that the high-altitude Sintaphu Lake, in the northwest of the country, overflowed at around 8:30 p.m. local time on Thursday. Authorities activated warning sirens along the Mochu sub-basin and the lower reaches of the Punatsangchhu River. According to local media, the flooding destroyed infrastructure at the Gasa Tshachu natural hot springs, a popular tourist destination, as well as facilities in Taktsemakhang. The affected areas had been evacuated before the flood, and no injuries or deaths had been reported.

Thousands evacuated in India

The flooding prompted alerts in India’s Alipurduar district in West Bengal and Dubri district in Assam, according to the Central Water Commission. Authorities in Alipurduar deployed Civil Defence personnel and moved thousands of residents to safer locations. Police Superintendent Amit Kumar Shaw told ANI that between 4,000 and 5,000 people had been taken to shelters, while more than 6,000 others had been relocated to safe areas.

Assam Chief Minister Himanta Biswa Sarma said authorities were monitoring the situation and preparing to address possible impacts downstream. Meanwhile, Bhutan’s NCHM reported that a new artificial lake had formed at Taktsi Makhang, where the Shintpahu Chhu and Lunana/Gangchen Taak Chhu rivers meet. Residents along the Mochhu and Punatsangchhu river valleys were urged to remain alert and avoid riverbanks and flood-prone areas.