Water availability in Rabi likely to drop by 25pc

LAHORE: Water availability in the Rabi season (2021-22) is likely to be 25 percent less than average usage, largely because of lower river flows during Kharif that could not fill up the Mangla Dam, The News has learnt.

Hence, it is feared cultivation of strategic wheat crop could be a challenge for the farmers. Last year, Indus River System Authority (IRSA) assessed 10 percent less water availability for last Rabi season (2020-21).

In 2019-20, water shortage was recorded at 15 percent lower than the average uses. Although the quantum of short supplies is said to be manageable, winter rains would play a significant role in meeting irrigation needs of the crops during the crucial stage of sowing and subsequent stages. As per initial assessment, against the total Rabi share of 36.4 million acre feet (MAF), 27.3 MAF water availability is expected, showing 25 percent shortfall.

The expected volume of water is also less than last ten year’s average of 32.20 MAF recorded in Rabi seasons. The projected shortfall will be equally shared by Punjab and Sindh provinces. Conversely, Khyber Pakhtunkhwa and Balochistan provinces have been exempted from the shortage as per Water Apportionment Accord 1991.

An official of Punjab Irrigation Department said through proactive approach, water regulation plan would be implemented to fulfill needs of crops through robust canal regulation arrangements. As far as Punjab’s share of water for Rabi season is concerned, against Average System usage of 19.75 MAF, Punjab’s share stands, as per Punjab para (2) calculated, at 18.87 MAF.

With 25 percent anticipated shortage, expected share likely to be 14.81 MAF. It is pertinent to mention here that stored water plays an important role in Rabi (winter) season due to relatively lesser flows in Rivers. However, as water storage capacity of existing dams is on the decline due to silting process, scarcity of water during Rabi season has become a permanent feature.

Rabi season begins from October 1 and concludes on March 31. The main crops of Rabi season include food staple wheat, gram, lentil (masoor), tobacco, rapeseed, barley and mustard. Owing to predominantly irrigated nature of the farming, Pakistan’s agricultural output is closely linked with the availability of irrigation water.

In the post-Mangla raising period, which adds close to 3 MAF of conservation capacity on river Jhelum, water shortages in late Rabi and early Kharif season have been minimised to negligible periods, but it had only happened when Mangla's expanded lake filled to maximum conservation level.

This year, even flows of other Western Rivers including mighty Indus River have been below normal as impounding of river Indus water to fullist level into Tarbela Dam to its highest storage level has become a reality unexpectedly very late.

The construction of Tarbela-V hydropower plant has reportedly been blamed for adversely affecting filling criteria of Tarbela Dam. It is learnt that despite clear advice by IRSA, the top water regulator, about filling of Tarbela Dam by following SOPs of filling, Water & Power Development Authority (WAPDA), the operator of water reservoirs, insisted on lowering the level of Tarbela lake at certain level to allow construction of intake tunnel.

Wapda insisted that the authority developed certain SOPs for filling of Tarbela reservoir, while keeping the safety of the dam in view. In order to ensure smooth operation of dam, Wapda has to ensure filling of dam, while keeping in view schedule of under construction intake tunnel.