KATHMANDU, OCTOBER 14

A new study by the International Centre for Integrated Mountain Development (ICIMOD) has revealed that the 2024 Thame flood in the Everest region was triggered by a chain reaction of geological and glacial factors, highlighting the area as a hotspot for glacial lake outburst floods (GLOFs).

The report, titled Thame Valley Glacial Lake Outburst Flood – Causes, Impacts, and Future Risks, confirms that a rock avalanche on 16 August 2024 struck two glacial lakes, releasing 459,000 cubic meters of water - equivalent to 185 Olympic-size swimming pools - and devastating the iconic trekking village of Thame. The flood displaced 135 people, destroyed 25 homes, and carried debris 80 km downstream.

According ICIMOD report, a rock avalanche triggered a powerful displacement wave when it hit a glacial lake at 4,900 metres, causing the lake to breach and releasing 156,000 cubic metres of water.

'This outflow fell 120 metres, amplifying its erosive power – and hit a second lake, whose moraine-dam then breached, leaving a hole 22-metre high (the height of an eight-storey building) and 51-metre-wide and releasing an additional 303,000 cubic metres of water. The combined waters transformed into a 'hyper-concentrated flow of slurry' as they swept downstream, transporting debris, including large boulders, 80km downstream and eroding riverbanks in its path,' the report added.

Experts warn that the Dudh Koshi river basin and the Everest region remain highly vulnerable, having experienced five significant GLOFs in less than 50 years. The report emphasizes urgent risk management and mitigation measures, including monitoring high-altitude glaciated areas and reinforcing riverbanks and moraine structures.

ICIMOD researchers note that 25,000 glacial lakes now exist across the Hindu Kush Himalayas, whose warming rates are nearly three times the global average, increasing the frequency and intensity of such disasters. The study combined satellite analysis, drone surveys, and on-ground geomorphological assessments to understand the flood's dynamics.

ICIMOD's co-authors stress that climate-driven hazards are escalating, and proactive planning, real-time monitoring, and engineering solutions are critical to protect downstream communities from future disasters.