Bhutan Lake Outburst Puts Bengal, Assam Administrations on Alert
Thimphu, October 30: Warnings of sudden flooding have been issued for several districts in West Bengal and Assam after a glacial lake in northwestern Bhutan burst open. The Shintaphu Lake breach has prompted local administrations to keep watch over communities living beside rivers flowing from the Himalayan kingdom.
The outburst took place on Thursday evening in Gasa district. Gasa Tsachu, a well-known natural hot spring close to the Mo Chhu river, was damaged as floodwater tore through the site. Because the area was cleared before the water arrived, no deaths or injuries have been reported.
Shintaphu Lake is located where the Mo Chhu river begins and is among 17 glacial lakes in Bhutan regarded as possible threats. The hot spring had already been hit hard on August 26, 2021, when the swollen Mo Chhu river altered its path and surged toward the spring.
Reports indicate the floodwater has moved beyond the Sringang area of Kabesa Gewog, about eight kilometres away from Punakha Dzong. Officials are now worried about what the surge could mean for areas farther down the river.
Bhutan has warned the administrations of West Bengal and Assam about possible danger to districts close to its frontier. Dhubri in Assam, along with the Darjeeling hills, Alipurduar and Jalpaiguri in West Bengal, have been identified as vulnerable zones.
Authorities in Cooch Behar have also cautioned those residing near the Sankosh river. The river starts in northern Bhutan and belongs to the network that channels water from the Himalayan region into the Brahmaputra in Assam.
Residents have been urged to stay alert, and officials have said that precautionary measures are in place.
Alipurduar Superintendent of Police Amit Kumar Shaw asked people to remain composed and said there was nothing to fear. On Thursday, he told a news service, "People are slightly frightened. I appeal to everyone not to panic. We are on alert, the administration is fully active, and all agencies are working actively, so there is no problem. We hope to find a way out and remove the troubles faced by the public."
The flash flood has also affected infrastructure in Bhutan. An official press release said a solar-powered irrigation lift system, set up earlier this year in the Dochukha-Jomlingthang-Ritsa Chiwog area of Guma Gewog in Punakha, was partly damaged by the sudden increase in the Mo Chhu's water level.
A local leader reported that the irrigation system is no longer functioning, though officials have not yet assessed the full extent of the loss.
Debris swept down by the floodwater has covered a stretch of the Punakha-Gasa highway near Jomlingthang, which may disrupt road links.
A glacial lake outburst flood happens when water collected in a lake formed by a retreating glacier suddenly drains out, frequently because a natural dam collapses. Heavy rain, landslides, avalanches, earthquakes or rapid glacier melting can cause such floods.
Human-induced climate change is pushing up temperatures and hastening glacier retreat, which is raising fears over glacial lake stability. A sudden discharge of water can develop into a powerful flood, putting people, infrastructure and farmland downstream at risk.