Glacial Lake Burst in Bhutan Sweeps Away Springs and Triggers High Alerts in West Bengal

A glacial lake outburst flood in Bhutan has washed away property at a popular hot spring site and prompted urgent evacuation alerts downstream in India.

What Happened

The Shintaphu glacial lake burst its banks late at night, sending a strong flash flood down the Mochu river basin. The rushing water damaged infrastructure at the Gasa Tshachu natural hot springs in northern Bhutan and washed away a section of the road leading to Laya village, closing it for traffic indefinitely. State broadcaster BBS noted that two portable Bailey bridges may also have been destroyed, while the National Center for Hydrology and Meteorology began monitoring water levels at Tashithang and informed Indian authorities.

Impact and Action

Although no deaths or injuries have been reported, the disaster prompted West Bengal state authorities to issue high alerts and evacuation warnings for residents living near the Sankosh River. State Forest and Environment Minister Manoj Kumar Oraon urged people in forest villages, tea gardens, and low-lying areas—including Kumargram, Chengmari, and Pakriguri—to move to safer ground immediately. Officials cited a breach in a Bhutanese dam and warned that floodwaters could surge downstream within a short window, pointing to a recent deadly disaster in neighbouring Nepal that killed more than 1,500 people as a reason for swift action.

Context

Glacial lake outburst floods happen when water held back by weak natural rock or ice dams suddenly breaks free, often triggered by melting ice in high mountain regions. The Gasa Tshachu hot springs were previously struck by a flash flood in 2021 when the Mochhu River shifted its course. Such sudden floods pose severe risks to downstream communities in the Himalayas, where narrow valleys leave very little time for warning and evacuation.