Bhutan glacial lake outburst puts Bengal and Assam on flood alert; over 10,000 evacuated

New Delhi: A glacial lake in northern Bhutan burst on Thursday evening, sending a surge down the Mo Chhu river system and putting the Sankosh on red alert in northern West Bengal and Assam, where authorities moved more than 10,000 people to safety.

The outburst occurred at Sintaphu Lake in Lungo, Laya Gewog, in Gasa district, one of 17 glacial lakes Bhutan lists as potentially dangerous. Around 7.4 million cubic metres of water is estimated to have been released. Floodwater reached Taktsemakhang at about 8.15 pm, damaging the road to Laya, washing away the Gasa Tshachu hot spring complex and cutting a section of the Punakha-Gasa highway. Two Bailey bridges were reportedly lost. Bhutan's National Centre for Hydrology and Meteorology is monitoring river levels at Tashithang and Yebesa, and warning sirens were sounded.

The water flows from the Mo Chhu into the Punatsangchhu and enters India as the Sankosh. A special advisory from the Union Jal Shakti ministry on Thursday said the flood would reach the border in six to eight hours and impact Alipurduar district in West Bengal and Dhubri in Assam.

Alipurduar is on red alert, with 4,000-5,000 people in relief camps and over 6,000 shifted elsewhere. SDRF and Civil Defence teams are deployed and an NDRF team is moving in. The Assam State Disaster Management Authority said the Sankosh level was steady at 6.30 am on Friday.

No casualties have been reported in Bhutan so far. The IMD has forecast heavy rain in Alipurduar on Friday, which could complicate relief work.

(With inputs from PTI and media reports)