Pakistan’s largest reservoir at Tarbela Dam has fallen to a dead level once again due to a considerable decline in rim station inflows and is potentially threatening a drastic reduction in provinces’ share.
The dam has again touched the dead level of 1,398 ft. SPD (revised by the Pakistan Water & Power Development Authority), which will affect the water supply to Sindh and Punjab, according to official data.
As per the data, its level was 1,414.33 feet on 16 May, with inflows of 984,000 cusecs and an outflow of 90,000 cusecs.
However, the inflows in River Indus at Tarbela fell to 68,900 cusecs (-29.98pc) within a week, which forced the authorities to reduce the outflows by 13.33 percent to 78,000 cusecs.
Similarly, the inflows in River Kabul at Nowshera decreased by around 4,000 cusecs from 34,900 to 29,900 cusecs.
The main reason for the dip in the inflow is the dip in Skardu’s temperature from 26.7 °C last Monday to 22.2 °C this week. The total inflows in the country’s rivers were 156,800 cusecs on Monday while the total outflows were 168,000 cusecs. The total storage at the Tarbela, Mangla, and Chashma reservoirs was 0.221 million acre-ft. (MAF).
The inflows in Jhelum at Mangla were 32,000 cusecs against the outflows of 34,100 cusecs, and inflows at Chenab at Marala were 27,200 cusecs, and the outflows were 17,200 cusecs.
Tarbela is currently operating at the minimum operating level of 1,398 ft. Its maximum conservation level is 1,550 feet, with a live storage today of 0.000 (MAF).
Mangla is presently at 1,084.55 ft against the minimum operating level of 1,050 ft. Its maximum conservation level is 1,242 ft., with live storage of 0.181 MAF.
Chashma is now at 641.00 ft against the minimum operating level of 638.15 ft. Its maximum conservation level is 649 ft, while the live storage is 0.040 MAF.
Last week, the Indus River System Authority (IRSA) informed the Provincial Secretaries of Irrigation that the rim station inflows have declined substantially from 206,109 cusecs on 15 May to 162,082 cusecs, which will affect the provinces’ shares of water.
It added that the inconsistency in temperatures has caused the rim station inflows to decline substantially by 44,027 cusecs (-21pc) from 206,109 cusecs on 15 May to 162,082 cusecs on 20 May. The storage component available at Tarbela, Chashma, and Mangla is only 0.344 MAF (last year — 0.995 MAF; 10-year average — 3.195 MAF), which is not sufficient to augment the dropping river inflows at the rim stations. The reduction will spread to the provinces, with a time lag of about four to five days to Punjab and 10 to 12 days to Sindh.
