ISLAMABAD: With an anticipated higher-than-normal temperature and an almost 31 per cent lower-than-usual snow bank, major crops in kharif (April-October) face a challenging outlook.

In addition, the unusual operational constraint at both major water reservoirs — Tarbela and Man­gla dams — and administrative weakness­es at the irrigation network are presenting a daunting task for water regulations.

With many ifs and buts, it was in this environment that the Irsa Advisory Committee (IAC) estimated 30pc water shortage in early kharif and about 7pc in late kharif. The uncertainty over water availability prevailed even after the IAC as the Water & Power Development Authority (Wapda) did not assure when major outlets at Tarbela dam (three tunnels and a low level outlet) could be made available for water discharges.

The meeting, presided over by Indus River System Authority (Irsa) Chairman Abdul Hameed Mengal, was not satisfied with the Wapda’s input as to when three tunnels (T3, T4 & T5) and the low-level outlet of Tarbela would be ready for use.

Irsa estimates 31pc shortfall in water supply

The uncertainty has been further aggravated after construction activities were suspended following the terrorist attack on Chinese workers. The only suggestion from the Wapda side was to “keep filling the reservoir,” which could mean a water shortage going up by 5-7pc to 35-35pc as the outflow capacity remains compromised even if the dam has enough stored water.

Therefore, the IAC constituted a committee comprising Irsa members from Sindh and Punjab and their respective chief engineers “to physically review and monitor the sites and furnish the report to resolve the operational constraints”.

Provincial share allocations

As such, the meeting also decided to go for water allocations among the provinces under 3-tier formula, albeit with muted opposition from Sindh for ‘principled reasons’ as there would be 63.61 million acre feet (MAF) of water for provincial shares against about 79MAF envisioned under the Water Accord.

Pakistan Meteorological Department “highlighted that during winter snowfall in the catchments of Indus & Jhelum recorded at 34.8 inches against the normal of 50.5 inches, i.e. 31pc less”, an official statement said adding that “PMD also forecasted higher than normal temperatures during the upcoming kharif season”.

This could create a new challenge. If higher temperatures lead to earlier melting of fewer than normal snow deposits, the water supply availability for irrigation in the later part could be constrained even further and there may be capacity problems in the wake of monsoon rains. This was more critical given that the PMD forecast pertained only to the April-June period and did not have any outlook for July-September.

As such, total water availability was estimated at 73.69MAF, of which 63.61MAF would be distributed among the provinces after leaving 10.1MAF for environmental reasons downstream Kotri. After setting aside KP and Balochistan share without shortage application, about 60MAF would go to Sindh (28.8MAF) and Punjab (31.13MAF).

The participants agreed that Punjab and Sindh would activate their respective Discharge Observation Cells (DOCs) for data reporting at different locations. Punjab SDOs will be stationed at Guddu, Sukkur and Kotri barrages in Sindh, while Sindh SDOs will monitor the discharges at Jinnah Headworks, Chashma Barrage, Taunsa and Panjnad headworks in Punjab.

Punjab and Sindh promised DOCs would be activated within a fortnight.

Rabi system operations

The meeting also reviewed the rabi 2023-24 (October-March) system operation and showed satisfaction about the overall seasonal close at 17pc shortages against the anticipated shortfall of 15pc.

While Sindh registered its muted stance against the continuation of the three-tier formula for the distribution of water shares among the provinces but acknowledged that little could be done at the Irsa level when the matter was pending before the Council of Common Interests.

Published in Dawn, April 3rd, 2024