A massive surge of water from a glacial lake in Bhutan has triggered flood alerts across parts of northern West Bengal and Assam, forcing thousands of people living along vulnerable riverbanks to move to safer locations. Approximately 7.4 million cubic metres of water surged out of the breached Shintaphu Lake in Bhutan. The water travelled through the Mo (Mofu) river system towards the Sankosh river, raising concerns about sudden flooding in parts of West Bengal and Assam. A special advisory issued by the Ministry of Jal Shakti on Thursday for Assam and West Bengal said the Indian Embassy had reported a GLOF in Shintaphu Lake in Bhutan’s Punatsangchhu river basin.
The outburst sent large volumes of water downstream through the Mo Chhu river towards the Sankosh river system, which forms the inter-state boundary between Assam and West Bengal.
The river rose by nearly two feet since this morning after a glacial lake in Bhutan’s Gasa region burst its banks on Thursday evening, unleashing a massive volume of water mixed with mud, rocks and debris into the downstream river systems. The flood washed away infrastructure at the Gasa Tshachu natural hot springs in Bhutan’s Gasa district. No injuries or loss of life have been reported, state broadcaster Bhutan Broadcasting Service (BBS) said on Friday.
Nearly 7.4 million cubic metres of water surged out of the breached Shintaphu Lake in Bhutan into the Mo River, causing an increase in Sankosh’s water level. “We have shifted 12,000 people to safer areas as a precautionary measure. The situation is under control at present,” an Alipurduar district official said.
The incident triggered flood alerts in parts of north Bengal and Assam, with authorities keeping a close watch on the water levels of rivers flowing down from the Himalayan kingdom. Sikkim, which witnessed massive devastation and loss of many lives in a glacial lake outburst flood in October 2023, however, remained unaffected in this disaster.
which forms the inter-state boundary between Assam and West Bengal, rose by nearly two feet since this morning after a glacial lake in Bhutan’s Gasa region burst its banks on Thursday evening, unleashing a massive volume of water mixed with mud, rocks and debris into the downstream river systems, according to official.
National Disaster Response Force (NDRF) personnel have been deployed in the affected areas in Alipurduar, while teams of the State Disaster Response Force (SDRF), Civil Defence and local administration are also being mobilised to strengthen the emergency response, the official said. “We are closely monitoring the water level and flow of the Sankosh River, while maintaining communication with officials in Bhutan to assess developments and obtain updates on the situation,” he said.
There have been no reports of major damage or casualties in the Sankosh-adjoining Kumargram area of Alipurduar so far, he added. Bhutan-originating rivers flowing through Jalpaiguri district, on the other hand, did not witness any water surge owing to the GLOF, another official said.
Authorities in West Bengal have alerted residents living along the Sankosh River and its tributaries following reports of the glacial lake outburst flood in Bhutan. Residents in the Darjeeling hills, Terai and Dooars regions have also been advised to remain alert and move to safer locations if they live in vulnerable areas. BJP MP from Darjeeling Raju Bista issued an alert through a post on X on Thursday, urging people living in the catchment areas of the Sankosh River and its connected tributaries to move to safer locations.
“A glacial lake outburst flood (GLOF) has been reported at Lemthang in Bhutan. The overflowing water from the lake is flowing downwards through the Mofu River towards the Sunkosh River,” the post read.
“Therefore, everyone living in the catchment areas of the Sunkosh River and all its connected tributaries have been informed to move to a safe distance immediately to protect their lives. Everyone in our Darjeeling hills, Terai and Dooars region are requested to stay alert,” he added.
State minister Nisith Pramanik said the government had received reports of the glacial lake outburst and that the overflowing water was moving towards the Sankosh River through the Mo Chhu River. “Reports have just come in regarding a glacial lake outburst in Bhutan. Water from the lake is overflowing and flowing downstream into the Mo Chhu River, heading toward the Sankosh River. Residents living along the Sankosh River and its tributaries have been alerted; they are advised to move to a safe distance immediately to ensure their safety,” Pramanik said. He said the water was expected to reach the plains within five to six hours, raising concerns about possible flooding. “To manage the situation, the State Disaster Management Team has been activated, and the NDRF has also been notified. Disaster management volunteers have been instructed to be present on-site. The government is taking proactive measures and closely monitoring the situation to prevent any loss of life or property,” he added.
An Assam State Disaster Management Authority spokesperson said the district administrations and response forces were on alert to tackle any eventuality. Another social media post by the CMO this evening said water levels in Dhubri and Kokrajhar remained steady following the GLOF.
“The district administrations are on high alert, with SDRF, NDRF, DDRF and Fire & Emergency Services teams kept ready for deployment. Officials are in constant touch with riverside communities, while ‘Aapda Mitra’ volunteers remain mobilised,” it said.
A special advisory issued by the Ministry of Jal Shakti on Thursday for Assam and West Bengal said the Indian Embassy had reported a GLOF in Shintaphu Lake in Bhutan’s Punatsangchhu river basin.Following reports of flash floods in the river’s upper reaches, water levels in the Sankosh River in India could rise suddenly in Assam’s Dhubri and West Bengal’s Alipurduar districts, the advisory said. Local authorities in the two districts have been advised to remain alert, closely monitor the situation and take necessary precautionary measures, it added.
A glacial lake outburst flood (GLOF), also known as a jokulhlaup, occurs when the natural dam holding back a glacial lake fails or is breached, releasing large volumes of water downstream. Such floods can cause sudden destruction of roads, bridges, settlements and other infrastructure, particularly in mountainous regions. Shintaphu Lake, located below Wakila Mountain in Lungo, Laya Gewog, in Bhutan’s Gasa district, is among 17 glacial lakes in the country identified as potentially dangerous, according to local reports. Gasa Tshachu, a popular natural hot spring in northern Bhutan, was also hit by a flash flood in 2021 when the Mochhu River changed course and swept through the area. The latest incident has renewed concerns over glacial lake outburst floods in the Himalayan region. In August, a flash flood near Nepal’s border with China killed more than 1,500 people and left over 5,000 missing, according to the supplied report.