Glacial lakes swell in Kishtwar, experts call for urgent safeguards

Preventive action urged without disturbing moraine dams

Study flags GLOF vulnerability, risk to Chenab infra

Mohinder Verma

JAMMU, Aug 29: With glacial lakes in the upper reaches of Kishtwar swelling steadily, there is a dire need to initiate preventive and mitigation measures without delay to minimise the risk of a possible Glacial Lake Outburst Flood (GLOF), even as experts caution that the findings should be viewed as a warning for preparedness rather than a prediction of any imminent disaster.

A detailed scientific assessment of the Brahma Group of Glaciers in the high-altitude terrains of the Kishtwar Himalayas has found a dramatic expansion of three glacial lakes over the past two decades. Analysis of satellite imageries covering nearly 20 years indicates that the area of these lakes, which was around 10 to 12 hectares two decades ago, has now increased to nearly 80 to 90 hectares.

The sharp increase assumes significance as continued enlargement of glacial lakes, particularly those held back by potentially unstable moraine formations, can increase the volume of water that could be released in the event of a breach.

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Prof Sunil Dhar, Department of Environmental Sciences, Central University of Jammu, was the Principal Investigator of the Department of Science and Technology (DST), Government of India-sponsored study titled “Glacio-hydrometeorology of Brahma Group of Glaciers” and was also an expert member of the J&K Government’s Focused Glacial Lake Outburst Flood Monitoring Committee.

The study describes the glacio-hydrometeorology and paleo-history of the Brahma Group of Glaciers as a crucial baseline for understanding water security and hazard risks in the Chenab River Basin. Prof Dhar’s study notes that the glacier group is a vital hydrological source, feeding local streams which flow directly into the Marwah River, a major tributary of the Chenab.

It has also flagged the vulnerability of several glacial lakes, including Mundiksar and Hangu, which are bound by unstable and unconsolidated moraine dams. “The glacial lakes are expanding constantly with every passing year”, the assessment notes, with the satellite record documenting their substantial enlargement over the last two decades.

Experts have consequently recommended controlled drainage of the vulnerable lakes to prevent further enlargement. However, such intervention would require detailed technical assessment to ensure that the existing impoundment is not disturbed or destabilised.

The geographical setting of the lakes adds another dimension to the issue as on one side lies the uninhabited area of the Zanskar region of the Union Territory of Ladakh, while on the other are major areas of Kishtwar district, particularly Warwan, Dachhan and adjoining areas.

This location, Prof Dhar stressed, makes scientific assessment and preparedness important from the perspective of both glacial hazards and downstream water flows. The potential consequences extend into the Chenab basin, where the glacier-fed streams eventually join the river system and where substantial hydropower and transport infrastructure has developed.

The research has highlighted the socio-economic infrastructure threats associated with a possible GLOF. “Downstream flash floods present a high risk to multi-billion dollar hydroelectric power projects operating along the Chenab cascade, alongside regional highways, bridges and local communities”, the study highlights.

A sudden release from a high-altitude glacial lake could carry large quantities of water along with sediment, rocks and debris, potentially magnifying its downstream impact. The presence of major hydropower projects and critical transport infrastructure therefore makes advance risk assessment and early-warning preparedness essential.

Significantly, the findings of the scientific assessment have also been shared with the Department of Disaster Management of the J&K Government, which had constituted the Focused Glacial Lake Outburst Flood Monitoring Committee vide Government Order No. 930-JK(GAD) dated April 4, 2024.

The committee was mandated to review the status of glacial lakes, identify those vulnerable to GLOFs, recommend site-specific technical measures to minimise the threat and define the roles and responsibilities of different stakeholders.

Prof Sunil Dhar was an expert member of the committee. Following its constitution, scientific expeditions were undertaken in different parts of Jammu and Kashmir to improve understanding of potentially dangerous glacial lakes and assess associated risks.

For the three expanding lakes in Kishtwar, experts have recommended controlled drainage/lake-lowering measures wherever technically feasible. The emphasis, however, is on carefully engineered intervention so that the process itself does not destabilise the moraine barriers.

The preventive strategy would also require continuous satellite observation, field inspections, assessment of moraine-dam stability and monitoring of lake levels and surrounding glaciers.

The proposed mitigation framework includes establishment of a fully functional Glacial Lake Outburst Flood Early Warning System, with trained personnel capable of interpreting warning indicators and facilitating timely response.

The experience of Nepal, where GLOF events have damaged downstream infrastructure and affected communities, offers a passing reminder of the vulnerability of Himalayan regions to sudden glacial-lake releases.

For Kishtwar, the scientific findings underline the value of acting before a crisis develops. The objective is not to create alarm but to ensure that the growing risk remains manageable through timely assessment, monitoring, early warning and technically sound mitigation.

With the Chenab basin emerging as one of the country’s important hydropower corridors, the expanding lakes underline the need to assess vulnerabilities scientifically and initiate feasible safeguards while there is sufficient time to do so.