Tarbela, Mangla storage rises to 12.7 MAF as river inflows ease

Pakistan’s major reservoirs at Tarbela and Mangla together held 12.734 million acre-feet (MAF) of live storage on September 11, 2025, with overall river inflows recorded at 262,600 cusecs and outflows at 234,800 cusecs.

The latest update from the Indus River System Authority (IRSA) shows Tarbela Dam at 1,550 feet, storing 5.728 MAF, with inflows of 149,400 cusecs nearly matching outflows of 149,000 cusecs. Kabul River contributed an additional 21,000 cusecs upstream of Nowshera, feeding into Tarbela’s system.IRSA releases 99,800 cusecs water

Key Takeaways

• Tarbela and Mangla combined live storage stood at 12.734 MAF, providing a buffer for upcoming Rabi crops.
• Total inflows into the Indus system were 262,600 cusecs, with 234,800 cusecs outflows.
• Kotri Barrage recorded 18.712 MAF escapage so far in Kharif 2025, easing Sindh’s delta water concerns.
• Skardu, Besham, and Partab Bridge inflows remained strong due to ongoing glacier melt, supported by warm northern temperatures.
• Experts caution that while storage is stable this season, sedimentation losses and rising demand continue to strain Pakistan’s long-term water security.

Mangla Dam on the Jhelum stood at 1,234.60 feet with live storage of 6.695 MAF, receiving inflows of 36,400 cusecs against controlled releases of just 9,000 cusecs. Together, Tarbela and Mangla account for nearly the entire strategic water storage available in Pakistan’s irrigation system at this stage of the Kharif season.

At Chashma Barrage, inflows were measured at 177,100 cusecs with outflows of 171,600 cusecs, leaving a live storage of 0.311 MAF. The Greater Thal Canal (GTC) drew 2,000 cusecs while the Chashma Right Bank Canal (CRBC) diverted 3,400 cusecs for irrigation supplies in Punjab and Khyber Pakhtunkhwa.

Downstream flows showed gradual depletion along the Indus as the river moves southwards. At Kalabagh, upstream discharge stood at 174,900 cusecs compared with 167,700 cusecs downstream. At Taunsa, the flow declined from 170,700 cusecs upstream to 158,200 cusecs downstream. Guddu Barrage recorded a further drop to 502,900 cusecs upstream and 476,000 cusecs downstream, while Sukkur registered 441,000 cusecs upstream and 412,700 cusecs downstream.

At Kotri, the last control structure before the Indus enters the Arabian Sea, inflows stood at 257,800 cusecs with outflows of 254,400 cusecs. IRSA noted that cumulative Kotri escapage during the current Kharif season (April 1 to date) has reached 18.712 MAF, a critical figure in assessing freshwater supplies to Sindh’s deltaic regions.

The Jhelum and Chenab system also showed steady but moderate flows. Rasul Barrage reported 8,100 cusecs upstream with 3,800 cusecs released downstream. At Marala, on the Chenab, 55,800 cusecs entered against 53,500 cusecs exiting downstream. Trimmu registered balanced flows of 188,000 cusecs both upstream and downstream, while Sidhnai showed 82,100 cusecs in steady passage. At Islam and Panjnad, the flows remained stable at 121,000 and 668,200 cusecs, respectively.

Upstream inflows from the northern catchments remained healthy, with Skardu reporting 87,800 cusecs, Partab Bridge 116,900 cusecs, and Besham 136,300 cusecs, reflecting continued glacier melt in the upper Indus Basin. Temperatures at Skardu, a key indicator of snow and glacier melt, ranged between a maximum of 29.4°C and a minimum of 18.3°C.

The combined live storage of 12.734 MAF as of September 11 is significantly above early-season levels but remains below the designed capacity of Pakistan’s reservoirs. Tarbela, originally designed to hold 9.7 MAF, has lost over 36 percent of its storage due to sedimentation, while Mangla, with an initial capacity of 5.3 MAF, was raised to 7.4 MAF after the 2010–11 dam-raising project.

Historically, September marks the tapering off of high flows from glacier-fed catchments as temperatures begin to drop in Gilgit-Baltistan and upper Khyber Pakhtunkhwa. Water managers expect a decline in inflows over the coming weeks, prompting careful regulation of releases to meet irrigation demand for late Kharif crops such as rice and cotton, while conserving supplies for the upcoming Rabi season starting October.

Experts warn that while Kotri escapage above 15 MAF during Kharif is considered sufficient to push back seawater intrusion into Sindh’s delta, long-term sustainability depends on enhancing storage capacity. Pakistan’s per capita water availability has already fallen below 1,000 cubic meters annually, placing the country in the category of “water-scarce” nations.

In recent years, IRSA has faced repeated disputes among provinces over water distribution, particularly between Punjab and Sindh. Sindh authorities consistently argue that reduced freshwater flow into the Indus delta is damaging mangrove ecosystems, fisheries, and agriculture. The current 18.712 MAF Kotri escapage for Kharif 2025 is expected to ease some of those concerns, although releases will decline sharply once winter regulation begins.

The monitoring of inflows from Skardu, Besham, and other upper catchments will remain crucial in the coming weeks. Climate variability, including shifts in glacier melt patterns and erratic monsoon rains, continues to complicate Pakistan’s water management. A 2022 World Bank report warned that without urgent investments in water storage and efficiency, Pakistan risks severe agricultural and hydropower shortages within the next decade.

As of this week, however, steady inflows and substantial Kotri releases suggest that the 2025 Kharif season has been relatively favorable compared to the extreme shortages reported in 2021 and 2022, when Kotri escapage had fallen to less than 5 MAF by mid-September.

IRSA is expected to announce its Rabi season projections later this month, factoring in current storage levels, anticipated inflows, and provincial irrigation demands. For now, Tarbela and Mangla’s combined 12.734 MAF live storage provides a comfortable buffer heading into the crucial wheat-sowing season.