Mangla Dam’s raising termed ‘wrong step’

Irsa says dam receives low water inflow, will only be filled once every five years.

ISLAMABAD:

The Indus River System Authority (Irsa) has expressed strong reservations against the Rs100-billion Mangla Dam Raising Project, terming it a ‘wrong step’.

In a report sent to the ministry concerned and the Water and Power Development Authority (Wapda), Irsa pointed out that following the raising, Mangla Dam would only be filled to its capacity once every five years.

Billions of rupees are being spent on a project that will not give the desired results, the report said, adding that “Wapda should have spent this amount on other mega projects such as Diamer Basha Dam.”

Meanwhile, the delay in the completion of the project has caused an escalation in its cost – over Rs119 billion from the revised cost of Rs101 billion, said a senior Wapda official. He added that issues over the resettlement of displaced families still exist.

Not enough water to fill the dam

“Following the Mangla Dam raising project, it will only be possible to fill the dam two times in 10 years at the desired level of 1,242 feet,” Irsa authorities noted in the report.

Irsa observed in the report that the project had been completed at a dam that receives the lowest inflows – 22 million acre feet (MAF) – of water per year from the River Jhelum.

In comparison, water inflows in the River Indus, where Tarbela Dam is built, stand at 60 to 85 MAF.

A Wapda official confirmed the observation but added that the project would have long-term benefits.

“Global warming is increasing and there is a possibility that the dam will be filled before the five-year period due to rapid melting of glaciers,” the official said.

However, the Irsa spokesperson denied any observation on the project.

Engineering mistake

In a meeting of the Executive Committee of National Economic Council (Ecnec) on May 26, it was pointed out that a strategic mistake was made in the 1960s in the engineering design of Mangla Dam, wherein a pond area was not provided for the extended lake area.

The mistake in the engineering design of the dam has caused a rise in the cost of the project, as well as a dispute between the government and the affectees over resettlement.

Mangla Dam

The dam was constructed on River Jhelum in 1967, with original live storage of 5.34 million acre feet (MAF), which reduced to 4.28 MAF due to siltation.

In order to restore and increase its capacity up to 7.16 MAF, Wapda initiated the project, for which the PC-1 was approved in 2003.

Under the project, the dam’s storage level was increased to 1,242 feet. Its original storage capacity was 1,234 feet, but had reduced to 1,210 feet due to silting.

An official of Wapda said that 0.5 MAF of additional water had been stored after the completion of the project.

Published in The Express Tribune, December 21^st, 2011.