Culture · Chungthang
Understanding the 2023 Teesta flood
At Chungthang you can see where the October 2023 glacial lake outburst destroyed the Teesta Stage III dam. A short, sober stop to understand how climate, glaciers and dams shape life and travel in North Sikkim today.
Photo: A. E. Racoviteanu, Y. Arnaud, M. W. Williams, … · CC BY 3.0, Wikimedia Commons
On 4 October 2023 South Lhonak Lake, a glacial lake far up the Lachen valley, burst and sent a wall of water down the river. At Chungthang it destroyed the dam of the 1,200 MW Teesta Stage III project, then swept on down the Teesta, taking bridges, roads, homes and lives. The Wikipedia article on the floods records that the lake had grown more than ninefold since 1977 as its glacier retreated.
From the road you can see the scale of change: the river runs wider and rougher, and rebuilding of roads, bridges and buildings has continued for years. The long closures of the Lachen road that followed, and the reopening in stages, are part of the reason we always say check current status before you travel.
Many local people lost family, homes or land. If you talk about the flood, listen more than you ask, and do not photograph damaged homes or people without permission.
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Questions travellers ask
Before you book
What happened at Chungthang in 2023?
On 4 October 2023 a glacial lake outburst flood from South Lhonak Lake swept down the Lachen valley and destroyed the dam of the Teesta Stage III hydropower project at Chungthang. The flood then damaged bridges, roads and homes far down the Teesta, causing loss of life, and cut off North Sikkim for months.
Is it safe to travel through Chungthang now?
Tourist traffic to Lachung and Lachen runs through Chungthang when roads are open, and authorities monitor the glacial lakes and rivers. Monsoon landslides remain the bigger everyday risk. Travel in the dry months where possible, follow your driver's advice and check current status before you travel.
Why did the Lachen road stay closed so long?
The flood and later slides destroyed long stretches of road and the bridge on the Lachen side, and these had to be rebuilt by the Border Roads Organisation. The road reopened in March 2026, closed again in April after a landslide, and permits resumed around mid-September 2026. Check current status before you travel.
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