Bhutan Glacier Lake Burst Triggers Flood Alert in West Bengal, Assam

The shocking images of devastating floods in Nepal are still fresh in memory when another potential natural disaster triggered by massive cloudburst has emerged in neighbouring Bhutan, raising fears of widespread flooding across the Himalayan foothills and downstream regions of India.

The Shinthapu glacial lake, located in Bhutan's Gasa district and associated with the headwaters of the Mochhu river, reportedly burst on Thursday afternoon, unleashing a massive volume of water downstream towards India.

Sirens sounded immediately after the incident, prompting residents living near the lake to flee. Several people were reportedly rescued from the danger zone.

Shinthapu is among Bhutan's 17 identified potentially dangerous glacial lakes. The incident has raised serious concerns over a possible Glacial Lake Outburst Flood (GLOF), a phenomenon in which water accumulated in a glacier-fed lake is suddenly released, often with devastating consequences.

Such outbursts can generate powerful torrents rushing through mountain valleys, carrying huge quantities of rocks, mud and debris. Settlements, roads, bridges and agricultural land along the downstream course are particularly vulnerable.

The immediate concern is the possibility of rising water levels in the Sankosh river, known as the Punatsangchhu in Bhutan. The river system eventually enters India, making downstream areas of West Bengal and Assam vulnerable to a potential flood emergency.

Bhutan's Department of Hydrology and Meteorology is closely monitoring the water level of the Mochhu river near Tashithang.

The Mochhu is connected to the wider Sankosh river system, heightening concerns over possible flooding in North Bengal.

An official of Bhutan's National Centre for Hydrology and Meteorology (NCHM) said a water-level monitoring station has been operational 24 X 7 at Takshimakhang, although no warning has so far been issued there till the receipt of preliminary reports.

Parts of Gasa District, Bhutan

High Alert for North Bengal & Assam

Bhutan has alerted India, while the country's Water Resources Development Ministry and North Bengal Development Department have also issued precautionary warnings.

Jalpaiguri and Alipurduar districts in North Bengal are among the areas under particular watch. Dhubri district in Assam and adjoining areas have also been cautioned.

Special attention is being paid to the Sankosh river and its tributaries. The region had witnessed considerable devastation in October 2025 following exceptionally heavy rainfall in Bhutan.

North Bengal Development Minister Nishith Pramanik said residents living along the Sankosh and its tributaries had been advised to move to safer locations.

Flooding could develop during the early hours of the morning, he warned, adding that state and district disaster-management teams have already been kept on standby.

Warning of a potentially dangerous situation, the minister said several areas could be inundated within an hour to an hour and a half as a result of which displaced wild animals, including elephants, might enter human settlements as floodwaters spread.

With the Himalayan region increasingly vulnerable to extreme rainfall, glacial instability and sudden flooding, the latest incident underscores how a natural disaster originating beyond India's borders can rapidly become an emergency for its downstream neighbours.