Due to heavy and continuous rainfall in the Alaknanda valley, the swollen river had eroded the toe of the slope. Already saturated debris material with diminishing shear strength failed because of this.   

An Interim Report on Preliminary  Geological  Slope Stability Assessment of the Recent Disaster Affected Areas in Parts of Chamoli District, Uttarakhand by Bhupendra Singh, Bhupender Singh, Ajay Kumar and Arindam Roy, Senior Geologists, M-IV, NR GSI Dehr
UK_CHA_NH_ 010
RD 490 km stone
Retaining wall with boulder crate deflection spurs, gabion walls, channelisation of surface run off through lined drains, filling of cracks on the road.
Heavy precipitation, toe cutting by Alakananda River, percolation of water through cracks leading to reduction in shear strength.