Depleting glaciers threat to power projects, water sources

Bhanu P Lohumi

Tribune News Service

Shimla, August 12

Glaciers in the Himalayan region are retreating following climate change which can lead to water scarcity for the people living downstream areas. The depleting glaciers can trigger the Glacial Lake Outburst Floods (GLOF) posing a threat to the sustainability of hydropower projects and adversely impacting water sources, people, livestock, forests, farms and other infrastructure, says a recent study conducted on glacier movement and GLOF.

The facts were highlighted in national workshop organised on GLOF organised by the Central Water Commission (CWC) held recently, which discussed the strategy and preparing of hazard maps of potentially dangerous lakes and their paths

Noting that the inventory of glacial lakes, undertaken independently by four groups, suggested the presence of 391 lakes in HP, the workshop stressed that potentially dangerous glacial lakes should be identified using standardised methodology and the lakes identified provisionally through investigations need to be prioritised for further investigations.

It also suggested overflight monitoring of potentially dangerous lakes regularly for monitoring GLOF hazard and vulnerability and risk assessment and establishing early warning systems and automatic weather monitoring observatories at such lakes on priority.

However, as per study conducted in 2012, the total number of glacial lakes in Himalayas is 251, including 12 critical, 93 potentially critical and 101 lakes with no potential. Glaciers and ice bodies cover 2,473 sqkm in Himachal which was 4.44 per cent of the total area of the state and all major rivers, the Sutlej, Beas, Chandrabhaga, Ravi and Yamuna, are fed by these glaciers.

The CWC is monitoring the Parechu lake and receiving information from China. The Parechu lake outburst in 2005 had incurred a loss of Rs 610 crore and National Highway-22 was washed away at a number of places. Ten bridges and 11 ropeways were washed away while 15 motorable bridges and 8 jeepable roads and 10 km stretch between Wangtoo and Sumdoh were damaged.

In 2014 Pejor Khud in Lippa was damaged and Rs 45 lakh was spent on reconstruction as the bridge which was washed away and pipelines of IPH Department were damaged, said Special Secretary (Revenue and Disaster Management) DD Sharma. Two lakes having highest GLOF threat identifies in Himachal are Gopang Gath and Samudra Tapu Lake in Lahaul and Spiti. The pro-glacial Gopang Gath lake was considered as critical, principally due to the steep slope of the downstream face of the moraine dam, the big lake area and the possibility for mass movements to occur from the surroundings of the lake.

Early warning system in the Sutlej basin – telemetry at Sumdoh by Snow and Hydrology division of the CWC, monitoring in the water level in the Sutlej and relay information system by the Nathpa Jahakri project at Dubling and wireless network at Reckong Peo are already in place, Sharma, who attended the workshop, said.