Centre maps 100 glacial lakes, 47 'glof facing' dams

New Delhi: Latest central assessments show that 47 hydropower projects are highly vulnerable to glacial lake outburst floods (Glofs) and more than half of these are in Himachal.

A year after a Glof in Sikkim killed nearly a hundred and wiped off Teesta IV hydropower plant, the Centre is focused on mapping critical glacial lakes and vulnerable hydropower projects and areas, and addressing these through scientific ways.

Fresh studies show 20 of the 47 vulnerable projects are in HP - NHPC's Baira Siul (180 MW), SJVN's Natha Jhakri (1,500 MW), private sector's Budhil (70 MW), Malana II (100 MW), Karcham Wangtoo (1,045 MW) and Chanju I (36MW) among others, ET has learnt.

There are nine such 'Glof facing' projects in Uttarakhand, from the one located in Dhauliganga to ones like Vishnuprayag and Tapovan Vishnugad. J&K is home to five such projects while Arunachal has three such dams.

Sikkim, which witnessed South Lhonak Glof in 2023, has another five that are seen as vulnerable.

Data shared at the National Committee on Disaster Risk Reduction workshop on 'strategies for Glof reduction' shows that mapping activity is on across the six impacted states after the Sikkim 'wake up' call. The panel was formed by NDMA after the disaster. Rounds of meetings have yielded considerable data and led to expeditions across states to map vulnerable areas.

Of the 7,500 glacial lakes in the Himalayas, nearly 200 are Glof vulnerable, as per a list drawn up by NDMA.

The Central Water Commission has now listed 100 of these as highly critical. Of the 100, 42 are in Sikkim, 15 each in Ladakh and J&K, 10 in HP and nine each in Uttarakhand and Arunachal.

Sikkim is home to a category-1 glacial lake while 16 such lakes are spread out, with 11 of them in Sikkim followed by three in HP. 69 glacial lakes have been categorised as category-3 lakes, with 27 in Sikkim and 12 and 11 in J&K and Ladakh, respectively. Sikkim is also home to 11 category-4 glacial lakes.

Glacial melt rate indicates that Glof activity may shift from eastern Himalayas to the Hindukush or central Himalayan range off J&K, Ladakh, HP and Uttarakhand, Ashim Sattar of IIT Bhubaneswar cautioned at the meet.