A reported glacial lake outburst in Bhutan has raised flood concerns in parts of West Bengal and Assam, prompting precautionary evacuations along the Sankosh River
A reported Glacial Lake Outburst Flood (GLOF) in the Shintaphu glacier region of Bhutan's Gasa district has triggered flood concerns in India's West Bengal and Assam. Rising water levels in the Sankosh River and its tributaries have prompted warnings and precautionary evacuations of people living in vulnerable riverside areas.
New Delhi: A reported glacial lake outburst in the Shintaphu glacier region of Bhutan’s northwestern Gasa district has raised flood concerns in parts of West Bengal and Assam. The sudden release of water from the glacial lake could increase water levels in the Sankosh River and its tributaries, placing settlements along the riverbanks at risk.
Authorities have issued warnings to residents in vulnerable areas and initiated precautionary evacuation measures. Reports indicate that thousands of people have been moved to safer locations.
Facilities in Bhutan’s Gasa Tshachu area have reportedly been washed away by floodwaters. However, the area had been evacuated in advance, and no casualties have been reported in the initial accounts.
What Is a Glacial Lake Outburst Flood?
A Glacial Lake Outburst Flood (GLOF) occurs when water accumulated in a lake formed by melting glaciers is suddenly released, causing flooding in downstream areas.
Such incidents can occur when natural dams made of ice, loose soil or rocks collapse. These dams hold back water in glacial lakes. When they fail, large volumes of water can flow rapidly down mountainous terrain, carrying rocks, mud and fallen trees.
The resulting floods can damage riverside villages, roads, bridges and agricultural land. They can also cause extensive destruction in downstream areas within a short period.
Which Areas Are Under Flood Alert?
Authorities have issued warnings for several vulnerable areas in West Bengal and Assam because of the potential rise in water levels.
- West Bengal: Kumargram in Alipurduar district and settlements along the Sankosh River.
- Assam: Low-lying riverside areas in Dhubri district.
- North Bengal: Darjeeling hills, Jalpaiguri and surrounding regions.
Residents in these locations have been advised to remain alert, monitor official updates and follow safety instructions issued by local authorities.
Why Is the Sankosh River at Risk?
Water flowing from Bhutan enters India through interconnected river systems. The Sankosh River passes through parts of North Bengal and Assam, making downstream settlements vulnerable to sudden increases in water levels.
If the volume of water rises sharply in the upper reaches of the river, low-lying villages and other riverside settlements could face flooding.
The potential impact depends on the volume of water released, river conditions and the movement of floodwaters downstream.
Authorities Take Precautionary Measures
West Bengal Forest Minister Manoj Kumar Oraon has appealed to people living along the Sankosh River to move to safer locations.
Authorities are monitoring river water levels and preparing to evacuate additional residents if required. Reports also indicate that road traffic in affected areas of Bhutan has been suspended following damage caused by floodwaters.
Initial reports have not established the exact volume of water released from the glacial lake or the extent of its possible impact in India. Therefore, specific figures, including claims that more than 6,000 people have been evacuated, require official confirmation.
Climate Change and the Risk of GLOF Events
Rising global temperatures are accelerating glacier melting, contributing to the formation and expansion of glacial lakes. This can increase the potential risk of outburst floods in vulnerable mountainous regions.
The reported incident in Bhutan highlights the importance of cooperation between India and Bhutan, particularly in sharing information about rainfall, river water levels and potential flood threats across their common border.
A major example of the destructive potential of GLOF events occurred in 2023, when an outburst from South Lhonak Lake in Sikkim caused extensive damage along the Teesta River valley.
