Sikkim GLOF fall-out: CWC to review designs of existing and under-construction dams

 Following Teesta-III Collapse, Committee Formed to Assess Lakes

THE PRINT, 08 August, 2024 : The Central Water Commission (CWC) has decided to monitor all the existing and the under-construction dams vulnerable to glacial lake outburst floods (GLOFs). This has been decided in the wake of the Teesta-III hydroelectric dam collapse in October 2023, a PIB press release stated.

The CWC has decided to monitor 902 glacial lakes and bodies of water including 477 glacial lakes and bodies of water having more than 50 hectares of water spread area every year.

The monitoring of these lakes will help in identifying the ones that have expanded substantially during the month, which can be the cause of major disasters. The monthly monitoring reports of the glacier lakes can be accessed on the CWC website.

A high-risk committee of disasters risk reduction under the NDMA has also been formed to send an expedition to directly assess the glacial lakes and prepare a comprehensive mitigation strategy for the state governments. This committee has been headed by the Union Home Minister.

To deal with the threat of GLOF, the state government of Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh have also approved a project worth Rs 150 crore for risk mitigation measures. This project will help in the early warning system and other structural and non-structural measures.

EOI, KOLKATA, AUGUST 8, 2024: Subsequent to the Teesta-III hydroelectric dam collapse at Chungthang in North Sikkim in October 2023, the Central Water Commission (CWC) has decided to review the designs of all existing and under-construction dams vulnerable to Glacial Lake Outburst Floods (GLOFs) and to ensure their adequate spillway capacity for acute flood conditions, says a PIB release. Further, GLOF studies have been made mandatory for all new dams planned, having glacial lakes in their catchments.

CWC monitors 902 glacial lakes and water bodies, including 477 glacial lakes and water bodies having a water spread area greater than 50 hectares and 425 glacial lakes having a size of 10 hectares to 50 hectares during the period from June to October every year. This enables the detection of relative changes in the water spread area of glacial lakes and water bodies, as well as identifying the ones that have expanded substantially during the monitoring month and could cause a disaster.

A Committee on Disaster Risk Reduction (CoDRR) under the National Disaster Management Authority, involving representatives from six Himalayan states and Union Territories and other stakeholders, has identified a set of high-risk glacial lakes. Expeditions would be sent to these lakes to prepare comprehensive mitigation strategies in terms of setting up early warning systems and other structural and non-structural measures.

A committee chaired by the Union Home Minister has approved a GLOF risk mitigation project for Rs 150 crore for the states of Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh to support the efforts of State Governments to take up various mitigation measures related to GLOF. A total of 47 dams, 38 of the commissioned and nine under-construction dams, have been identified by the Central Electricity Authority. These are likely to be affected by Glacial Lake Outburst Floods from the glacial lakes in the Indian territories. GLOF studies have been completed for 31 projects.

The Ministry of Earth Science, through its autonomous institute, the National Centre of Polar and Ocean Research, has been monitoring and carrying out scientific research on two pro-glacial lakes in the Chandra Basin since 2013. In a National Mission on Himalayan Studies-sponsored study titled ‘Snow and Glacier Contribution and Impact of Climate Change in Teesta River Basin, Eastern Himalaya,’ the status of glacial lakes in the Sikkim Himalayas has been prepared by the National Institute of Hydrology, Roorkee.