Pakistan’s major reservoirs, Tarbela and Mangla have reached their maximum capacities in hopeful signs for the agricultural landscape of the country for both ongoing and upcoming crop seasons.
Presently, the combined storage of the two dams has surpassed 13.1 million acre-feet (MAF), hovering just shy of their conservation limits which are attributed to operational and precautionary measures for unforeseen flash flows from rain and thunderstorms, reported Dawn.
These developments come against the backdrop of Pakistan’s two principal crop seasons — Kharif and Rabi. The Kharif season spans from April to October, while the Rabi season extends from October to April. Notably, Kharif crops include rice, sugarcane, cotton, maize, moong, mash, bajra, and jowar, while Rabi crops comprise wheat, gram, lentil (masoor), tobacco, rapeseed, barley, and mustard.
Khalid Idrees Rana, spokesperson for the Indus River System Authority (Irsa), reassures that water scarcity is not a concern at the moment. As Rana notes, there is even a surplus in the system, with further rainfall anticipated.
This surplus lays the groundwork for carrying over more than 10 MAF of water to the forthcoming Rabi cropping season in October, potentially marking a positive shift for Rabi crops after several years.
It should be noted that the current Kharif season started in April amid forecasts of a 37 percent water shortfall. Notably, current water levels on the Chenab River favorably support the Jhelum-Chenab canal command areas.
A similar trend is observed in the Eastern rivers — Ravi, Beas, and Sutlej — which now have plenty of water following a decade-long dry spell. Because of the quantity of water downstream from these rivers, the reliance on Mangla has been reduced. This mega-dam on the Jhelum River has attained an elevation of 1,240 feet, just two feet below its peak elevation of 1,242 feet following several years of construction.
With ongoing diversion from the Indus Zone to the Jhelum-Chenab Zone, the Mangla Dam is anticipated to reach full capacity in the coming days.
The resurgence of flow patterns in the Eastern rivers carries implications of climate change, signaling a shift in weather and flow dynamics after a considerable interval. Amidst the intricate dance of water and weather, the populace downstream is urged to exercise caution along old river beds.
With the Pakistan Meteorological Department (PMD) forecasting medium to heavy rainfall in Tarbela’s catchment areas and favorable temperatures in Skardu’s snowy peaks, the stage is set for increased river flows. As water availability in dams exceeds 13 MAF by the end of the current month, the immediate water requirement for the present crops is anticipated to be around 2.5 MAF.
This prudent allocation ensures a healthy carryover storage of approximately 10.5-10.7 MAF for the forthcoming Rabi season commencing on October 1, 2023.
Meanwhile, Indian reservoirs on the Sutlej and Beas rivers are nearing maximum levels, leaving limited room for further storage. Given the expectation of moderate to heavy rainfall in the upper catchments of these rivers, India is projected to be forced to release flows into Pakistan in the near future.
As of August 14, total inflows at the rim stations reached 377,000 cusecs, exceeding total outflows of about 357,000 cusecs. While discharges from the Tarbela dam currently surpass inflows, Mangla dam’s outflows are held at a cautious 10,000 cusec, compared to its inflows of about 30,000 cusecs. Since the onset of the current Kharif season on April 1, roughly 7.34 MAF of water has flowed downstream through the Kotri barrage.
Source: Pro Pakistani