Rishiganga

2021 glacial outburst flood

Starting approximately 10:45 a.m. IST on 7 February 2021, a flooding disaster occurred all along the river and its gorge following a landslide, avalanche or glacial lake outburst flood.

Flash flood on February 7 in Chamoli district, Uttarakhand, claimed at least 72 lives with at least 200 missing. Now, Geological Survey of India (GSI) has submitted its report on causes of the disaster.

Key findings:

The flash flood was due to a large mass of snow, ice and rock avalanche along with a hanging mass of rock crashing into the Raunthi Garh valley floor. This impact pulverised the combination of rock, snow and ice, causing a rapid flow downstream of Raunthi Garh and into the Rishiganga valley leading to the deluge. A contributory factor was unusually warm weather in the region. There was no evidence of a Glacial Lake Outburst Flood (GLOF) having caused the event.

What happened on February 7?

A glacial break in the Tapovan-Reni area of Chamoli District of Uttarakhand led to massive flash flood in Dhauli Ganga and Alaknanda Rivers, damaging houses and the nearby Rishiganga power project.