Thimpu/Kolkata/Guwahati: A high alert was sounded in northern Bengal and parts of Assam after a major Glacial Lake Outburst Flood (GLOF) in the high-altitude Himalayan region of Bhutan on Thursday evening.
Bhutan also evacuated residents from areas close to rivers likely to be impacted by the flood.
Authorities in both Indian states have initiated emergency monitoring protocols as swollen transboundary rivers carrying massive volumes of glacial melt and debris flow downstream towards the northeastern plains.
District administrations issued urgent advisories to riparian communities to avoid riverbeds and prepare for potential evacuation, even as disaster management teams were deployed along vulnerable riverbanks.
The sudden surge in water levels could have poses a direct threat to downstream infrastructure, agrarian lands, and riverine settlements bordering Bhutan.
The outburst occurred in the upper reaches of Bhutan’s glacial ecosystem, where rising temperatures and structural instability in ice-dammed moraine lakes caused a catastrophic breaching event. The resulting torrent rapidly entered the major river systems that drain directly into Assam’s Brahmaputra valley and the northern Dooars of West Bengal, as reported by News18.
Round-the-clock control rooms to track river discharge rates have been established by state disaster response forces, alongside local administrative machinery. Flood warnings have been sounded in key border districts, including Kokrajhar, Baksa, Chirang, and Dhubri in Assam, alongside Jalpaiguri and Alipurduar in West Bengal, where rapid water level spikes could trigger flash flooding and severe bank erosion.
The incident highlights the escalating environmental hazards facing the Eastern Himalayas, where rapid climate shifts have accelerated glacial retreat and expanded high-altitude proglacial lakes. Glacial lake outbursts are notoriously unpredictable, releasing millions of cubic metres of water within hours and overwhelming downstream river basins before conventional warning systems can fully activate.
The crisis follows the catastrophic transboundary flooding that hit the Nepal-Tibet border region in August 2026, where high-altitude slope failures and glacial lake surges triggered massive debris flows. That event devastated border infrastructure and sent floodwaters carrying silt and debris downstream into India, illustrating the critical, shared vulnerability of the entire Himalayan belt.
