The Flood Forecasting Division (FFD) has warned that tributary nullahs of the Chenab and Ravi rivers could experience high flooding amid forecast rainfall in the upper catchments of the country’s major rivers.
The FFD said flows at major rim-gauging stations of the Chenab and Ravi were expected to remain in the low-flood range, while adjoining nullahs could face low to medium flooding. However, a significant rise in flows in tributary nullahs could push them into the high-flood category.
It forecast no major increase in inflows at the main gauging stations of the Indus, Kabul, Jhelum, Ravi and Sutlej rivers over the next 24 hours, although several stations could reach low-flood levels.
Flows at Taunsa, Marala, Khanki, Qadirabad and Sidhnai were expected to enter the low-flood range, while Tarbela, Kalabagh, Chashma, Guddu and Balloki were likely to remain at low flood levels.
The FFD also warned of possible flash flooding in tributary streams of the Kabul River and hill torrents in the Dera Ghazi Khan division during the forecast period.
According to the department, Tarbela Dam, Kalabagh and Chashma on the Indus were experiencing low-level flooding on Friday evening. Flows recorded at 6pm on Aug 14 stood at 268,200 cusecs at Tarbela, 365,870 cusecs at Kalabagh and 321,667 cusecs at Chashma.
The FFD forecast widespread rain, strong winds and thunderstorms, with isolated heavy rainfall, over the upper catchments of all major rivers during the next 24 hours.
The affected areas include Islamabad, Gilgit-Baltistan, Kashmir, upper Khyber Pakhtunkhwa and several districts of upper Punjab.
The department said Tarbela reservoir had reached its maximum conservation level, while Mangla was at 67pc of its capacity and had yet to reach its maximum level.
According to Wapda’s daily report for Aug 14, Tarbela recorded inflows of 274,100 cusecs and outflows of 273,300 cusecs. At Nowshera, inflows and outflows of the Kabul River were recorded at 32,700 cusecs each.
At Mangla, the Jhelum recorded inflows of 28,400 cusecs and outflows of 7,000 cusecs. The Chenab at Marala had inflows of 81,000 cusecs and outflows of 62,000 cusecs.
Tarbela Dam’s water level stood at 1,550 feet, its maximum conservation level, with live storage of 5.580 million acre-feet (MAF). Mangla’s level was recorded at 1,209.75 feet against its maximum conservation level of 1,242 feet, with live storage of 4.870 MAF.
Chashma lake stood at 648.50 feet, half a foot below its maximum conservation level of 649 feet, with live storage of 0.285 MAF.
Wapda said the inflows and outflows reported at Tarbela, Jinnah and Chashma, as well as the Kabul at Nowshera and Jhelum at Mangla, represented 24-hour mean flows.
