No glacial lake found in Dharali: Landslide or glacier collapse likely culprit, experts warn danger
A joint expert team has ruled out a glacial lake burst behind the August 5 Dharali disaster. After trekking across the Srikanth Mountain, investigators say the flash flood may have been caused by a hanging glacier collapse or a landslide lake burst triggered by rainfall.
Uttarkashi: In the aftermath of the devastating flash flood that struck Dharali village in Uttarkashi district on August 5, a team of experts from the Nehru Institute of Mountaineering (NIM) and the State Disaster Response Force (SDRF) has ruled out the possibility of a glacial lake burst.
Their conclusion came after a high-altitude investigation across the Srikanth Mountain range, the origin of the Kheer Ganga stream.
A flash flood devastated Dharali on August 5
The flood, which occurred around 1:30 PM, swept away the bustling Dharali market, destroying homes, hotels, and shops. At least five people were confirmed dead, while many others remain missing. The sudden surge of water left behind a trail of destruction, prompting urgent rescue and relief operations by the Army and SDRF.
Search for the source
Soon after the disaster, SDRF teams from Jolly Grant headquarters reached Dharali and began drone-based monitoring of the affected area. On August 7, a team climbed to an altitude of 3,450 meters on the right side of Kheer Ganga and conducted aerial surveys. No lake was found.
The next day, the team ascended to 3,900 meters below the Srikanth mountain and captured drone footage of the drainage patterns above Kheer Ganga and Dharali. This data was shared with scientists from the Wadia Institute of Himalayan Geology and U-COST for further analysis.
SDRF conducted a physical inspection of the glacier base and the Kheer Ganga origin site
On August 14 and 15, SDRF conducted a physical inspection of the glacier base and the Kheer Ganga origin site, reaching heights of 4,812 meters. Despite harsh weather—whiteouts, strong winds, and rain—the team used Phantom-4 and DJI Mini-2 drones to collect detailed visuals. Their findings confirmed that no glacial lake existed in the area.
Inspector General of SDRF, Arun Mohan Joshi, informed, "We reached the spot and tried to see if any lake was being formed. At present, no such evidence is visible in the pictures.”
What can be the possible causes?
With the glacial lake burst theory ruled out, experts are now exploring other possible causes:
Hanging glacier collapse
Renowned geologist Navin Juyal believes the disaster was triggered by the collapse of a hanging glacier—patches of snow and ice perched in shallow mountain dips. These remnants from the Little Ice Age are unstable and prone to sudden avalanches.
Juyal explained that moderate rainfall from August 3 to 5, combined with unusually heavy spring snowfall, may have saturated the glacier’s base. This could have led to a rock-and-ice avalanche that sent water, debris, and rocks crashing down the KheerGanga valley. He also warned that similar events might occur in nearby rivers like Harsil Gadh and Jhala Gadh, urging authorities to monitor these areas closely.
Landslide lake burst theory
Piyush Rautela, former executive director of the State Disaster Management Authority (SDMA), proposed another theory. He said that continuous rainfall may have triggered a landslide, forming a temporary dam. When this dam burst, it unleashed a sudden flood. Local villagers support this theory, noting that the water level in Kheer Ganga had dropped just before the flood—possibly due to water being held back by the landslide dam.
No cloudburst occurred
Not a Cloudburst Initially, the Uttarakhand government suggested a cloudburst caused the disaster. However, IMD scientist Rohit Thapliyal clarified that only light to moderate rainfall was recorded in the region during the relevant period. This rules out the cloudburst theory.
Climate change and unabated construction
Experts say the Dharali disaster is a wake-up call about the dangers of climate change and unplanned construction in the fragile Himalayan region. A former geologist warned that the area is not suitable for dense human settlement. He pointed out that many of the damaged buildings were constructed on the river’s old natural path, making them highly vulnerable.
Impose strict controls on construction activities
Scientists have urged the government to impose strict controls on construction activities in sensitive zones and improve disaster preparedness. They also recommend regular monitoring of glaciers and drainage systems using satellite data and drone technology.
Rescue and relief efforts
Immediately after the flood, Army personnel from the Harsil camp rushed to Dharali to begin rescue operations. Helicopters were deployed for aerial support, and both state and central governments began monitoring the situation. SDRF teams worked tirelessly to locate survivors and assess damage.
While the exact cause of the disaster is still being studied, the SDRF’s high-altitude inspection has provided crucial data for scientists. The findings will help shape future disaster response strategies and guide infrastructure planning in Uttarakhand’s vulnerable regions.