Culture and history · Chungthang
Understanding the 2023 Teesta flood
On the night of 3–4 October 2023, a glacial lake burst far upstream and the flood destroyed the Teesta III dam at Chungthang within minutes. Stop, look at the riverbed and the rebuilt road, and understand why North Sikkim's roads still close so often.
South Lhonak is a glacial lake in Sikkim's far north-west, dammed by a wall of moraine left by a retreating glacier. Scientists had watched it grow for decades, from about 17 hectares in 1977 to around 167 hectares by late September 2023. In 2018 pipes were even carried up by yak to try to pump water out. An early warning system was being installed.
In early October 2023, extreme rain fell over Sikkim. On the night of 3–4 October the lake breached. The flood reached Chungthang around midnight. Dam operators, warned by the Indo-Tibetan Border Police, tried to open the gates, but the 1,200 MW Teesta III dam was destroyed in minutes. Downstream, water rose 15–20 feet and bridges and highway stretches were swept away.
Today you see a widened, grey riverbed, rebuilt sections of road and the remains of the dam. Many local people lost relatives, homes and livelihoods. Ask questions gently, if at all. The flood is the main reason we tell you, again and again, to check current status before you travel.
Cost: Free
Questions people ask
Good to know
What caused the 2023 Sikkim flood?
Heavy rain in early October 2023 led to the breach of South Lhonak, a glacial lake dammed by moraine in Sikkim's far north-west. The released water became a glacial lake outburst flood down the Teesta, destroying the Teesta III dam at Chungthang and damaging towns and highways downstream.
Is the Teesta III dam still damaged?
The dam was destroyed in the October 2023 flood, along with the bridge to its powerhouse. Repair and rebuilding plans have been discussed since. Visitors see the damaged site from the road; do not enter work or security areas or photograph installations.
Is it safe to travel through Chungthang now?
When the road is open and permits are issued, tours travel through daily. The risk comes from landslides and road damage, especially in the monsoon. Follow the advice of your driver and the authorities, avoid monsoon travel, and check current status before you travel.
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