Full Breakdown
Glacial Lake Outburst at Shintaphu Lake Triggers Flood Alerts in Bhutan and India
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In this breakdown
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Core Event: Sudden Release of Water from Shintaphu Lake
A glacial lake outburst flood (GLOF) struck Thursday evening when Shintaphu Lake—one of Bhutan’s 17 potentially dangerous glacial lakes—burst its moraine dam in Gasa district, north-western Bhutan. The surge washed away infrastructure at the Gasa Tshachu hot springs, a tourist site, and damaged a section of the Punakha-Gasa highway. No injuries or fatalities were reported because the area had been evacuated in advance.
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Background & Context
Glacial lakes form as retreating glaciers leave depressions that fill with meltwater; a moraine failure can release water in minutes, creating a flash flood. The Bhutan alert linked the outburst to accelerated glacier melt amplified by climate change. The Gasa Tshachu site previously suffered a major flash flood on August 26, 2021, when the swollen Mo Chhu River altered its course.
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Data & Statistics
- The outburst released roughly 74 lakh cubic metres (7.4 million m³) of water into the Sankosh River system.
- Bhutanese media reported two bailey bridges may have been washed away.
- In West Bengal’s Alipurduar district, authorities evacuated 6,000–7,000 residents and set up shelters for more than 4,000 people in schools.
- Floodwater crossed Srigang in Kabesa Gewog, about eight kilometres from Punakha Dzong.
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Official Statements & Responses
- Bhutan’s national broadcaster Bhutan Broadcasting Service (BBS) announced the outburst, ordered evacuations and warned of downstream impacts.
- India’s Flood Forecast Monitoring Directorate (Central Water Commission, Ministry of Jal Shakti) issued a special advisory for Alipurduar (West Bengal) and Dhubri (Assam), forecasting a rapid rise in water levels.
- West Bengal’s Minister of State for Home and Hill Affairs Bishal Lama confirmed alerts were sounded in the Dooars region, especially along the Sankosh River.
- Superintendent of Police Amit Kumar Shaw (Alipurduar) said there was “no need to panic” and that authorities were prepared for any contingency.
- Chief Minister Suvendu Adhikari (West Bengal) reported the situation had stabilized and that all 47 people previously reported missing were safe.
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Verbatim Quotes
- “Alert has been sounded in parts of Dooars, particularly near the Sankosh River,” — Bishal Lama
- “Throughout the night, until 4 am, the SP, ministers, MLAs, and the DM were all on-site, working. They were also in constant touch with our control room here,” — Suvendu Adhikari
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On-the-Ground Reports
Local police and disaster teams broadcast public-address announcements across blocks such as Nagrakata and Banarhat, urging residents to stay alert. Relief centres in schools provided dry rations and baby food. By the following morning, water levels in the Sankosh River had receded slightly, and many evacuees began returning home while officials continued to monitor the flow.
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Conflicting Reports & Gaps
- The precise volume of water released is reported only by the Indian Express; other outlets did not specify a figure.
- The extent of structural damage in Bhutan remains unclear, with BBS citing “darkness and the strong flow” as limiting assessment.
- While two bailey bridges are believed to have been washed away, no official confirmation has been published.
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What’s Next
West Bengal and Assam remain on high alert as rain clouds linger over the Dooars. District administrations are tracking real-time hydrological data from Bhutan and keeping disaster-response teams on standby for any further surge.