As filling season of dams ends, water level in region's reservoirs remains below normal

Vijay Mohan

Tribune News Service

Chandigarh, October 2

Dams in the region have commenced the depletion period on a deficient note, with significant deviation from normal being recorded in all major reservoirs this year. 

The lower water levels in dams comes in the wake of the monsoon in the region being less than normal.

There are three reservoirs in Himachal Pradesh--Bhakra and Kol dam on the Sutlej and Pong dam on the Beas-- where the combined storage is 17 per cent below normal.

The storage at the single reservoir in Punjab at Thein dam that lies on the Ravi is 24 per cent below normal.

The five-month filing season for the dams, which depends on snow melt and rains, lasts from May 1 to September 30. With the monsoon retreating thereafter and dropping of temperatures in the mountains reducing snow melt, inflows into the reservoirs also subside. The dams are critical for irrigation, flood control as well as hydro-power generation.

The combined storage available in Himachal Pradesh is 12.48 billion cubic metres (BCM) whereas the current storage is 9.06 BCM, according to data released by the Central Water Commission (CWC) on October 1. The availability was 11.06 BCM at this time last year and was an average of 10.96 BCM over the past 10 years.

While the maximum water level at Bhakra has been 512.06 metres, the present level is 504.18 metres, translating to the available storage being 71 per cent of its total capacity. It was 86 per cent for the corresponding period last year and an average of 88 per cent over the last 10 years.

The present water level at Pong  is 418.27 metres against the maximum of 423.67 metres, with the available storage being 74 per cent compared to 91 per cent last year and 88 per cent over the last 10 years.

The total capacity of Thein dam is 2.34 BCM, with the current storage being 1.39 BCM, which is just 59 per cent. It was 85 per cent last year with the past 10-year average being 78 per cent for this time of the year. The water level presently is 13.67 metres below the permissible limit of 527.91 meters.

From autum to spring, there is very little inflow into the reservoirs and the stored water is released as per the requirements of the states for domestic and irrigation purpose, thereby depleting the levels.