Indian Himalayan Watershed's Transboundary Issues and Resilience Strategies
The National Glacial Lake Outburst Flood Risk Mitigation Programme (NGRMP) is currently active in four Himalayan states - Arunachal Pradesh, Himachal Pradesh, Sikkim, and Uttarakhand - with a total project outlay of ₹150 crore, of which ₹135 crore is the central share from the National Disaster Management Fund (NDMF).
The programme, focused on creating a scientific inventory of glacial lakes, identifying high-risk lakes, and assessing their capacity and moraine dam stability, has made significant strides. It employs satellite analytics, expert validation, field surveys including bathymetric measurements, slope surveys, and Electrical Resistivity Tomography (ERT), and real-time monitoring through the installation of Automated Weather Stations (AWS) and Early Warning Systems (EWS) at key locations. As of July 2025, about ₹27.73 crore has been released for implementation.
The Central Water Commission (CWC) is monitoring 902 glacial lakes via satellite imagery, using Synthetic Aperture Radar (SAR) to detect changes even during clouded monsoon months. The programme also integrates community engagement to enhance preparedness and resilience downstream and incorporates infrastructure strategies such as drainage, embankments, and retention structures for climate resilience.
Looking ahead, the National Disaster Management Authority (NDMA) is shifting proactively from post-disaster response to risk reduction, aiming to expand surveillance beyond existing hotspots and update risk mapping continuously. Expansion of early warning tools like the Flash Flood Guidance System (FFGS), which provides 6–24 hour advance flood warnings and operates in India as part of a South Asian regional initiative, is also part of the strategy.
However, challenges remain, particularly in the realm of trans-boundary cooperation. Neighbouring countries like Nepal have suffered severe Glacial Lake Outburst Flood (GLOF) incidents but face challenges due to the absence of early warnings from China for trans-boundary lakes in Tibet. This underscores the need for cross-border early warning systems and collaborative action. India is part of regional flood warning cooperation among South Asian countries, but wider formal engagement on trans-boundary GLOF data sharing and mitigation requires further strengthening.
The NGRMP is advancing technically and institutionally with improved monitoring, risk assessment, and community involvement. Future plans include scaling early warning systems and infrastructure resilience. Enhanced trans-boundary cooperation remains a recognized but challenging priority.
Post-GLOF siltation raises riverbeds, undercutting future flood-carrying capacity. Over 100 downstream dams have been flagged by the Central Water Commission (CWC) for urgent retrofits. There are 195 high-risk lakes on the dynamic watch-list under the NGRMP. Nearly two-thirds of Himalayan GLOFs are triggered by ice/rock avalanches or landslides.
There have been multiple GLOF events in the Hindu-Kush Himalaya since 2023. India's Indus Treaty experience offers a template for a tri-national early-warning compact with reciprocal data feeds and joint drills. There is a need for lake top siphoning before dam commissioning to prevent GLOF events.
The Climate-Induced Multi-Hazard Chain views a GLOF as a cascade: glacier retreat → lake expansion → slope destabilisation → dam breach → hyper-sediment flood. The 2025 Lehende-Khola flood highlighted the absence of a China-Nepal-India Cryosphere Alert Protocol. The 2025 Rasuwagadhi GLOF disrupted at least four operational hydropower plants, signaling the macro-economic stakes of trans-boundary early-warning gaps.
Fewer than 40 functional hydromet stations are available above 4,500 m across 2,400 km of the Himalayas. The Indian Himalaya hosts one of Earth's fastest-retreating glacier systems. Glacial retreat is generating thousands of new melt-water ponds perched above densely populated valleys. India lacks a dedicated permafrost observatory network, hampering dam-failure prediction models.
Rapid warming and permafrost degradation are key drivers of GLOF events. The Chorabari Kedarnath event in Uttarakhand in 2013 resulted in over 5,700 deaths due to a cloudburst and moraine breach. The South Lhonak flood in Sikkim in 2023 caused the loss of the Teesta III dam worth $2 billion due to intense monsoon melt and weak moraine.
Over 28,000 glacial lakes have been mapped across the Indian Himalayan River Basins. Trans-boundary data gaps exist, as upstream nations hold satellite and hydrological data close, stalling early warnings. The NGRMP relies on interim grants; long-term scaling hinges on 16th Finance Commission allocations (FY 2027-31).
The programme's success will be crucial in mitigating the risks posed by GLOF events in the Indian Himalayas, ensuring the safety of communities and infrastructure downstream.
- The environmental science of the NGRMP focuses on monitoring and assessing the health-and-wellness of glacial lakes, considering their impact on climate change and the potential for medical-conditions like flood-related injuries and losses.
- As part of their strategy, the programme incorporates elements of medical-conditions preparedness by integrating community engagement and infrastructure strategies like drainage, embankments, and retention structures for climate resilience.
- The NGRMP also emphasizes the importance of science and technology in its approach, employing tools such as satellite analytics, Electrical Resistivity Tomography (ERT), and the installation of Automated Weather Stations (AWS) and Early Warning Systems (EWS) to better understand and address the risks associated with Glacial Lake Outburst Floods (GLOFs).
