Expert teams to assess five high-risk glacial lakes of Uttarakhand

The Uttarakhand government has assembled two expert teams to evaluate the risk and survey five glacial lakes prone to “outburst floods” in the state.

Of the 188 glacial lakes in Himalayan states, 13 are located in Uttarakhand, Secretary Disaster Management, Uttarakhand, Ranjit Sinha said and added that these have been categorised according to their vulnerability to the threat of “outburst flood”. Uttarakhand in February 2021 saw a glacial lake outburst in Chamoli district that washed away a small hydel project on the Rishiganga and caused flash floods, killing many people.

Glacial lake outburst flood (GLOF) is a flood resulting from the sudden and rapid release of water from a glacial lake, often caused by the breaking of a moraine dam or ice dam.

The 13 glacial lakes of Uttarakhand have been categorised as ‘A’, ‘B’ and ‘C’, with ‘A’ being highly sensitive, said Sinha, who on Tuesday participated in an online meeting with the Disaster Management Division of the Union home ministry on glacial lakes.

Sinha said that five of the 13 glacial lakes in Uttarakhand fall in category ‘A’, four in category ‘B’ -- sensitive -- and four in category ‘C’ -- relatively less sensitive. Out of the five highly sensitive lakes, four are in Pithoragarh district and one in Chamoli, and of the four sensitive lakes, two are in Pithoragarh and one each in Chamoli and Tehri, he said.

Two separate teams have been formed to conduct the risk assessment of the five highly vulnerable glacial lakes in the first phase, Sinha said and added that the risk assessment work of these lakes is proposed to begin in May-June this year. The first team consisting of experts from the National Institute of Hydrology, Roorkee; the Geological Survey of India, Lucknow; the Indian Institute of Remote Sensing, Dehradun; the Uttarakhand State Disaster Management Authority; and the Uttarakhand Landslide Mitigation and Management Centre will assess the sensitivity of two glacial lakes.

The work of the first phase will entail satellite data study and data collection, bathymetry and area survey, Sinha said.