A glacial lake outburst flood (GLOF) at Shintaphu Lake in Bhutan's northern Gasa district on Thursday evening, October 29, sent a surge of water down the Mo Chhu river towards India, triggering flash-flood warnings in West Bengal and Assam. The Central Water Commission's Flood Forecast Monitoring Directorate issued a special advisory on Thursday saying a flash flood had been reported in the upper reaches of the Punatsangchhu in Bhutan — the river that becomes the Sankosh after crossing into India — and that the water was expected to reach the India-Bhutan border within six to eight hours.

Source: IANS (via hi INDiA)

The biggest response was in West Bengal's Alipurduar district. Superintendent of Police Amit Kumar Shaw said about 4,000 to 5,000 people had been moved into shelters, mostly school buildings, and more than 6,000 others had been shifted to safer places, and he appealed to residents not to panic, saying the administration was in constant contact with the Bhutanese authorities. NDRF and SDRF teams were deployed at Tufanganj and Boxirhat in Cooch Behar district, and alerts were also issued for the Darjeeling hills, Jalpaiguri and Cooch Behar.

Source: NE Insider

4,000–5,000people moved into shelters in Alipurduar, per SP Amit Kumar Shaw
6,000+more people shifted to safer places in West Bengal
17potentially dangerous glacial lakes listed in Bhutan — Shintaphu is one of them
0deaths or injuries reported as of Friday morning

Damage inside Bhutan

In Bhutan, floodwaters washed away the infrastructure at Gasa Tshachu, the well-known hot spring complex beside the Mo Chhu in Gasa district, according to Bhutan's state broadcaster BBS and local reporting. A section of the Punakha-Gasa Secondary National Highway near the 31.85-kilometre point was completely washed away and the road has been closed to all traffic until further notice; flood-borne debris had earlier covered a section of the same highway. The surge, which reached Taktsemakhang at about 8.15 pm, also partially damaged a solar-powered irrigation lifting system in Punakha district installed earlier this year.

Source: Daily Bhutan

Assam on alert, greatest risk passes

Assam Chief Minister Himanta Biswa Sarma said on X that the state was closely monitoring the situation and that the Dhubri administration was on the ground and prepared for any downstream effects. No damage or displacement had been reported from Assam as of Friday morning, and officials said the period of greatest flash-flood risk in the Indian areas had passed, though preparedness is being maintained.

Source: NE Insider

Shintaphu Lake, at the source of the Mo Chhu below Wakila Mountain, is one of Bhutan's 17 glacial lakes identified as potentially dangerous. A glacial lake outburst happens when water held back by a natural dam of ice, rock or moraine is suddenly released. Bhutanese authorities are still assessing the lake's condition and the full extent of the damage; the cause of the release and the volume of water involved had not been confirmed by Friday morning. People living along the Sankosh in Assam and West Bengal have been advised to stay away from riverbanks and low-lying areas and to follow district administration and disaster-management alerts.