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The Lahaul-Spiti district administration announced on 31 August 2026 that an early warning system will be installed at the Ghepan Ghat glacial lake in September, the first such system for a glacial lake in Himachal Pradesh.
Deputy Commissioner Kiran Bhadana said the system will be set up through C-DAC Thiruvananthapuram and will monitor lake level and other parameters with real-time transmission of data; it was tested successfully at Sissu Lake first.
A Geological Survey of India team was to begin a 14-day study of glacial lake outburst flood risk at the site from 1 September.
ISRO had alerted the administration in November 2023 that the lake had expanded well beyond its normal extent, and 34 vulnerable locations have been identified between Sissu and the state boundary.
A sudden outburst would send water and debris into the Chandra river, threatening Lahaul villages, the Manali-Leh national highway and the Atal Tunnel.
As a glacier retreats it leaves behind a hollow that fills with meltwater, held back by the moraine of unconsolidated rock and sediment the glacier dumped at its snout, or by remaining ice. Neither is engineered, and neither is stable. The barrier can be overtopped by a wave from an ice or rock avalanche into the lake, piped through internally as water finds a path through the loose debris, or destabilised by seismic shaking. When it goes, the release is not a flood in the ordinary sense but a fast, sediment-laden surge that can travel tens of kilometres and destroy bridges, roads and settlements far downstream. The danger grows as warming enlarges the lakes, which is why the size of a lake over time, rather than any single season's weather, is the quantity being monitored.
Simple Analogy: It is a reservoir behind a wall of loose rubble that nobody designed and nobody can reinforce.
ISRO alerts the district administration that Ghepan lake has expanded significantly beyond its normal extent
An NDMA team inspects the lake to assess flood risk from the melting glaciers feeding it
A catastrophic flood strikes settlements along the Trishuli in Nepal and the China border area, killing more than a thousand people, sharpening attention on Himalayan lake and glacier hazards
The Lahaul-Spiti administration announces that the early warning system will be installed in September through C-DAC Thiruvananthapuram
A Geological Survey of India team begins a 14-day study of outburst risk at the lake
Building and installing the early warning system, which will monitor lake level and other critical parameters and transmit the readings in real time
Conducting the 14-day field study of glacial lake outburst flood risk at the site
Inspected the expanding lake and issues the national guidelines that shape glacial lake risk management
Satellite monitoring of glacial lakes; alerted the administration to Ghepan's expansion in November 2023
The October 2023 outburst of South Lhonak lake in Sikkim devastated the Teesta valley and destroyed the Chungthang dam, and remains the reference case for GLOF risk in India
The disaster along the Trishuli occurred under clear skies, and seismic analysis pointed to a glacier collapse rather than rainfall, a reminder that Himalayan flood hazards are not only monsoon-driven
The Chandra joins the Bhaga at Tandi to form the Chandrabhaga, which becomes the Chenab, so a Lahaul event sits at the head of a major Indus-system river
The 9.02 km tunnel under the Rohtang Pass, inaugurated in October 2020, connects Manali to the Lahaul valley and gives the region all-weather access
GS Paper 3 > Disaster and disaster management; GS Paper 1 > Physical geography of India and important geophysical phenomena
General Awareness > Indian Geography and Current Affairs
The sudden release of water from a glacial lake when its moraine or ice dam fails, producing a fast, debris-laden surge downstream
The ridge of unconsolidated rock and sediment deposited by a glacier, which frequently forms the unstable natural dam of a glacial lake
A glacier occupying a steep tributary valley high above the main valley floor; three of them feed Ghepan lake
Instrumentation plus a communication and response chain that converts detection of a hazard into timely action by people at risk