Pakistan’s largest reservoir at Tarbela Dam has plummeted to a dead level due to rim station inputs, endangering provinces’ share.
The dam has again reached 1,398 ft. SPD (updated by the Pakistan Water & Power Development Authority), which may affect water supply to Sindh and Punjab.
On 16 May, its level was 1,414.33 feet, with 984,000 cusecs of inflow and 90,000 cusecs of outflow.
The inflows at Tarbela decreased to 68,900 cusecs (-29.98%) within a week, forcing authorities to reduce outflows by 13.33% to 78,000 cusecs.
Similarly, River Kabul inflows at Nowshera reduced by 4,000 cusecs.
Skardu’s temperature dropped from 26.7 °C last Monday to 22.2 °C this week, reducing inflow. Monday’s river inflows totaled 156,800 cusecs and outflows 168,000 cusecs. Tarbela, Mangla, and Chashma reservoirs held 0.221 million acre-feet (MAF).
Jhelum inflows at Mangla were 32,000 cusecs, and Chenab inflows at Marala were 27,200 cusecs.
Tarbela is at 1,398 ft. Its highest conservation level is 1,550 feet, with 0.000 live storage (MAF).
Mangla is at 1,084.55 ft, compared to 1,050 ft. Maximum conservation level is 1,242 ft. with 0.181 MAF live storage.
Chashma is at 641.00 ft compared to 638.15 ft. Maximum conservation is 649 ft, and live storage is 0.040 MAF.
The Indus River System Authority (IRSA) informed provincial irrigation secretaries last week that rim station inflows have dropped from 206,109 cusecs on 15 May to 162,082 cusecs, affecting the provinces’ water sharing.
Inconsistent temperatures have reduced rim station inflows by 44,027 cusecs (-21%) from 206,109 cusecs on 15 May to 162,082 cusecs on 20 May. The storage component at Tarbela, Chashma, and Mangla is only 0.344 MAF (last year — 0.995 MAF; 10-year average — 3.195 MAF), which is insufficient to boost river inflows at rim stations. The reduction will spread to Punjab and Sindh with a four- to five-day lag.