THIMPHU / ALIPURDUAR — A glacial lake outburst flood (GLOF) in Bhutan on Thursday evening has triggered flood alerts downstream in India.
The sudden release from Shintaphu Lake, also called Shintaphu Tsho, below Wakila Mountain in Gasa district, sent a surge into the Mo Chhu river. The lake is listed among Bhutan's 17 potentially dangerous glacial lakes in the Punatsangchhu basin. The Punatsangchhu is called Sankosh after it enters India.
In Bhutan, damage was reported in two places. The Solar Irrigation Lifting System in Dochhukha-Dzomlingthang-Ritsa Chiwog under Guma Gewog in Punakha was partially damaged and has stopped functioning. Installed earlier this year to address water shortages, its full damage is yet to be assessed.
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Second, debris was swept onto a section of the Punakha-Gasa Highway in Dzomlingthang area, disrupting connectivity. Local Tshogpa reported it. Bhutan state broadcaster BBS also reported infrastructure at Gasa Tshachu, the famous natural hot spring near Mo Chhu, was washed away, and two Bailey bridges may have been lost. The road to Laya village has been closed.
No casualties reported so far in Bhutan. Floodwaters had crossed Srigang in Kabesa Gewog, about 8 km from Punakha Dzong, by Friday morning.
An official of Bhutan's National Centre for Hydrology and Meteorology (NCHM) said a water-level monitoring station at Taktsimakhang exists, but had not triggered an alert when first reports came.
Because Mo Chhu flows into Punatsangchhu, which becomes Sankosh in India, the Indian government acted fast.
On Thursday night, Ministry of Jal Shakti and Central Water Commission issued a special advisory: Indian Embassy in Thimphu reported GLOF at Shintaphu, flash flood in upper Punatsangchhu could raise water levels suddenly in India within 6-8 hours, particularly Alipurduar in West Bengal and Dhubri in Assam. Advisory flagged Darjeeling hills, Jalpaiguri, Cooch Behar also.
Assam Chief Minister Himanta Biswa Sarma said state is monitoring Dhubri and Kokrajhar. BJP MP from Darjeeling Raju Bista asked people along Sankosh and tributaries to move to safer places. At least 4,000 people in North Bengal were moved to relief shelters overnight as precaution. By 6.30 am Friday, CWC said Sankosh level steady.
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For India-Bhutan, this is a climate warning. Bhutan has 3,000+ glacial lakes, 17 dangerous. Earlier, 1994 Lugge Tsho GLOF killed 21 in Bhutan. Rising temperatures mean moraine dams weaken. Punatsangchhu-II hydropower project has shut units and opened dam gates as precaution.
*Tags:* #GLOF #Bhutan #ShintaphuLake #Sankosh #Punatsangchhu #Gasa #Punakha #FloodAlert #Alipurduar #Dhubri #MoChhu #ClimateChange