ISLAMABAD: Even though it is in a better position than last year and 10-year average availability, the country is estimated to face 15 per cent water shortage during the ongoing Rabi season that began on October 1.

“The basin-wise shortage for Rabi 2023-24 was approved at 15pc,” said the Indus River System Authority (Irsa) after a meeting of its advisory committee presided over by its chairman Asjad Imtiaz Ali on Monday.

The committee’s meeting was called to chalk out the anticipated water ava­i­lability criteria for Rabi 2023-24 (Oct-March). It was attended by all four members of Irsa from Balo­chistan, Khyber Pak­h­tu­nkhwa, Sindh and Pun­jab, besides representati­ves of the Federal Flood Co­mmi­ssion, provinces and Water and Power Dev­e­lopment Authority (Wapda).

Total water requirement for Rabi crops, under the Water Apportionment Accord of 1991, is about 37-38MAF.

The committee, however, noted that likely water availability of 31.66 million acre feet (MAF) at canal heads was about 8pc higher than last year’s actual availability of 29.39MAF and 10-year average of 29.42MAF.

The 1991 Water Accord empowers Irsa to determine water availability in the country and the provinces’ share twice a year, for Kharif and Rabi seasons. Rabi season starts from Oct 1 and ends on March 31, while Kharif starts from April 1 and continues till Sept 30.

The anticipated water shortage for the current Rabi season is expected to dent mainly the wheat crop. Wheat is the largest crop in Rabi season. Gram, lentil, tobacco, rapeseed, barley and mustard are some of the other Rabi crops.

The meeting was informed that due to better inflows and efficient regulation of available supplies, the storage volume available for Rabi 2023-24 was 11.579MAF, which was 15pc more than 10-year average and 19pc more than last year.

On the recommendations of Irsa’s technical committee, the meeting approved the likely anticipated water availability at the four rim stations of 21.92MAF for Rabi 2023-24, which was about 8pc more than that of previous year and about 1pc less than 10-year average.

As such, total availability at canal heads was estimated at 31.66MAF. Therefore, the committee decided to cut the water share of Punjab and Sindh by 15pc on the basis of 29.77MAF water availability after excluding the share of Balochistan and KP which are historically exempted from water shortages because of constraints in their irrigation network.

As such, Punjab was allocated 16.97MAF share for the entire cropping season, followed by 12.8MAF for Sindh. Balochistan and KP was allocated 1.18MAF and 0.71MAF, respectively.

At the request of Wapda, the Irsa advisory committee also approved schedule for closure of Chashma Barrage for a period of 20 days between the tentative dates from Dec 26, 2023 to Jan 14, 2024, synchronised with annual canal closure schedules for Punjab and Sindh canals. During the closure, Chashma reservoir would be constrained between levels 638.15 feet and 640ft with outflow restrictions between 15,000 and 30,000 cusecs.

The meeting also took up Wapda’s request for carrying out operation and maintenance works at Jari outlet of Mangla reservoir, but decided to consider it later after provincial canal closures during mid-term review of the water situation.

Wapda’s member water also updated the advisory committee about Tunnel-5 (T5) hydropower plant of Tarbela and reported that best efforts were being made to complete the ongoing work during the approved closure period of 33 months.

The meeting noted with satisfaction the culmination of Kharif season on Sept 30 at better than anticipated water availability. The meeting was informed that actual inflows at rim stations stood at 95.22MAF till Sept 30 that were 3pc higher than forecasted volume of 92.88MAF, but 6pc less than 10-year average of 101.55MAF.

The overall provincial canal withdrawals were 15pc short with respect to their allocated shares for Kharif. Punjab and Sindh received 14pc short supplies against anticipation of 15pc, while KP and Balochistan got full indented supplies. The actual system losses were 14.15MAF as compared to the anticipated 13.53MAF.

Published in Dawn, October 3rd, 2023