Sikkim identifies 16 high-risk glacial lakes and plans lake-specific safeguards
Where it stands
Sikkim said on 3 September 2026 that 16 of its glacial lakes carry high risk. National studies list 189 vulnerable glacial lakes in India, 40 of them in Sikkim. Sikkim has mitigation plans for Shako Cho, the Lhonak complex and the Gurudongmar complex. The Union Home Secretary reviewed five Himalayan states and union territories on 3 September 2026. On 5 September 2026 IIT Mandi researchers reported nine fast-growing glacial lakes in Himachal Pradesh. Himachal's total glacial lake area grew 28.45 per cent in ten years. Himachal has sought Rs 105 crore for early-warning systems at four lakes. The Central Water Commission will map flow paths for 681 Himalayan glacial lakes. All these measures are plans or works in progress.
Background
Glaciers can leave lakes behind as ice retreats. Rock and loose sediment often hold the water in place. An earthquake, icefall or rising water can break this natural barrier. The sudden release is a glacial lake outburst flood. South Lhonak Lake released such a flood on 3-4 October 2023. Sikkim reported damage worth ₹18,555 crore. The disaster damaged roads, bridges and hydropower assets.
How it developed
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Night of 3-4 October 2023How it started
South Lhonak flood drives a new programme for glacial-lake risk
South Lhonak Lake released a glacial lake outburst flood during the night of 3-4 October 2023. Sikkim later put the damage assessment at ₹18,555 crore. The event became the basis for the state's current lake studies and mitigation work.
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3 September 2026New fact
State maps 16 high-risk lakes and prepares three mitigation plans
Sikkim presented its latest risk work on 3 September 2026. National studies identified 189 vulnerable lakes across India. Forty are in Sikkim. State teams classified 16 as high risk. Field teams completed detailed studies for 13 lakes. Three lakes cannot be reached on foot. Sikkim prepared separate mitigation plans for Shako Cho, the Lhonak complex and the Gurudongmar complex. The Central Water Commission proposed 10 early-warning systems. Sikkim is also preparing a floodplain zoning law.
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5 September 2026New fact
IIT Mandi flags nine fast-growing glacial lakes in Himachal Pradesh
PTI reported the IIT Mandi study on 5 September 2026. The team mapped 2,076 glacial lakes above 3,500 metres in Himachal Pradesh in 2025. The count rose by around 710 since 2015. The total lake area grew 28.45 per cent in ten years. Nine lakes are growing fast: Kalikund, Chandratal, Vasuki, Surai, Kya Tso, Yoche, Samudra Tapu, Kasang and Gepang Gath. Gepang Gath in Lahaul-Spiti grew by about 244,000 square metres. More than 15 bridges, several settlements, schools and health facilities lie in the hazard zones. Government agencies list four Himachal lakes as sensitive. Three of the four appear in the IIT Mandi list.
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3 to 5 September 2026Official response
Centre reviews Himalayan states. Himachal seeks Rs 105 crore for early warning.
Union Home Secretary Govind Mohan chaired a review meeting in New Delhi on 3 September 2026. Chief secretaries of Uttarakhand, Himachal Pradesh, Sikkim, Arunachal Pradesh and Jammu and Kashmir attended. The Home Secretary asked the states to speed up the GLOF mitigation project sanctioned in 2024. Himachal Pradesh has sought Rs 105 crore from the Centre for early-warning systems at four major glacial lakes. The Central Water Commission will map flow paths and downstream risk for 681 Himalayan glacial lakes. The National Disaster Management Authority will develop an integrated risk-categorisation framework. PTI reported the Himachal request and the CWC and NDMA plans on 5 September 2026.
Why it matters for UPSC
For GS1 and GS3, connect glacier retreat with Himalayan disaster risk. Remote sensing screens lakes before field teams measure depth, slopes and dam strength. A hazard list guides monitoring, early warnings and engineering plans without predicting an immediate flood.
Key terms
Sources (7)
- Press Information Bureau · official · DST, Govt. of Sikkim Organises One-Day Media Sensitisation Workshop on GLOF Risk Mitigation in Gangtok4 Sep, 2:25 pm
- Business Standard · Sikkim identifies 40 high-hazard glacial lakes, 16 at highest risk4 Sep, 2:25 pm
- The Tribune · Himachal Himalayan lakes expand up to 60% in 10 years, 9 of 12 at critical risk: IIT Mandi study (2 September 2026)6 Sep, 1:45 am
- PTI · 9 expanding glacial lakes in Himachal pose flood risk: IIT-Mandi study (5 September 2026, PTI copy in Business Standard)6 Sep, 1:45 am
- ANI · At least nine Himalayan lakes critical as glacial melting expands them: IIT Mandi research (2 September 2026)6 Sep, 1:45 am
- Press Information Bureau · official · Union Home Secretary Reviews Preparedness of Himalayan States/UT for GLOF and Snow Avalanches (3 September 2026)6 Sep, 1:45 am
- The Tribune · After Nepal flash flood, 16 glacial lakes in Sikkim identified at highest risk of outburst (4 September 2026, PTI copy)6 Sep, 1:45 am