THERE are many pros and cons in any project. But one has to draw a line at a point where the benefits outweigh the losses.

One of the main concerns of those who don’t want Kalabagh dam to be built is that in the event of a recurrence of the 1929 record flood, the flooding of Peshawar valley including Nowshera town would be aggravated.

One should look at what was the cause of flooding at Nowshera and Peshawar valley. The upstream entrance of Kabul river at Nowshera into the confined channel at the end of Peshawar valley and back-water effect of Attock gorge downstream through which Indus river has to pass after its confluence with Kabul river.

Before the confluence, the Indus river flows through a wide valley of over 8,000 feet and is then forced to pass through a 1000-feet wide gorge for 5 miles. This constriction forces the river water to back up thus raising flood levels in Kabul river upto Nowshera.

The Kalabagh dam should not adversely affect flooding in Nowshera and Peshawar valley, and an upstream dam on Swat river would provide effective assurance against this chronic inherent problem.

In the modified design of the project, the reservoir conservation level has been lowered by 10 feet from 925 to 915 feet above mean sea level (MSL) thus eliminating the need for construction of any protective dyke near Nowshera.

At maximum conservation level of 915 feet, the back-water effect of Kalabagh would end about 10 miles downstream of Nowshera. A state-of-art computer based study, backed by physical modeling in Pakistan, has established that recurrence of record flood of 1929 would not affect the water level at Nowshera even after 100 years of sedimentation in the reservoir. It is high time that decisions are made on merit considering only the logical and technical reservations of all stakeholders.

Saleem Raza

Quetta

Published in Dawn, August 30th, 2015

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