Amidst severely deficient rains over north-west India in the pre-monsoon period, the water level in key dams in the region that are crucial for power generation and irrigation has slipped below normal.
The combined storage at dams in Himachal Pradesh at present is 2 per cent below normal, though it was a few notches above normal in the beginning of June. The water level at Punjab’s sole dam is 28 per cent below normal.
The reservoir at Bhakra Dam that lies on the Sutlej in Himachal Pradesh is filled up to 31 per cent of its total capacity, while that at Pong on the Beas, also in Himachal, is filled up to 20 per cent of its capacity.
The average storage at these two dams over the past 10 years was 29 per cent and 24 per cent, respectively.
At Thein Dam on the Ravi in Punjab, the current storage is 36 per cent of its total capacity compared to the past 10-year average of 50 per cent, according to the latest weekly report issued by the Central Water Commission (CWC).
Bhakra and Pong have a combined hydro-power generational capacity of about 1800 megawatts (MW) and irrigation potential of 676 thousand hectares.
A third dam in Himachal, Kol, which lies upstream of Bhakra has miniscule storage capacity but has a hydel potential of about 800 MW. Thein can generate about 600 MW and irrigate 348 thousand hectares.
The water inflow at Bhakra Dam is primarily dependent on snow melt in Kinnnaur and Tibet, while that at Pong and Thein is largely dependent on rain received in their catchment areas.
The filling season for the dams is generally from mid-May till the end of September, when snow in the upper reaches of the Himalayas starts to melt and the region also experiences rain.
The inflows peak during the monsoon, which this year is expected to arrive in Himachal, and then in Punjab, after June 25. It has already covered peninsular India and the north-east.
During the month of June so far, the agrarian states of Punjab and Haryana have faced a rain deficit of 74 per cent and 77 per cent, respectively, the hill state of Himachal is short by 57 per cent, according to data released by the India Meteorological Department (IMD).
Rainfall in these states was severely deficient in May this year also, with the shortfall being 86 percent in Punjab, 79 per cent in Haryana and 72 per cent in Himachal. Rain is crucial for the agriculture sector.