Glacial Lake Outburst Floods are emerging as a Himalayan disaster of the climate-change era. Discuss the lessons from Sikkim South Lhonak GLOF and the institutional response required.

Introduction: The South Lhonak Glacial Lake Outburst Flood of 3-4 October 2023 destroyed the 1,200 MW Teesta-III dam and killed 100+ in Sikkim; ISRO Cartosat mapping (2024) identified 38 high-risk glacial lakes in the Indian Himalaya; the NDMA Guidelines on GLOF were released in 2020.

Body: First, drivers — climate-driven warming, rapid lake expansion, and moraine instability create cascading risk; the Chamoli flash flood of 7 February 2021 and the Kedarnath disaster (2013) signalled earlier warnings, and Nepal's Imja GLOF risk is a comparator. Second, institutional response — NDMA is piloting early-warning siren systems at seven high-risk lakes, with CWC, IMD, and Geological Survey of India coordinating downstream hazard mapping. Third, infrastructure exposure — multiple hydropower projects sit in the Teesta and Alaknanda cascades.

Way forward: Roll out universal early-warning systems at high-risk lakes, mandate GLOF risk-rating before EIA clearances, pilot siphon-and-pump drawdown at Lhonak, and relocate vulnerable settlements under NDMA-MoEFCC by 2028.