LAHORE: The Water and Power Development Authority (Wapda) suspended power generation for a couple of hours at Mangla after Tuesday’s earthquake jolted the country’s biggest dam, but decided to resume supply after concluding that it was safe to do so.

Power generation at Mangla resumed at 7.20pm, restoring 700MW to the national grid and easing fears of a spike in loadshedding.

On the other hand, Punjab’s irrigation department shut the Upper-Jhelum canal as a precautionary measure to avoid any damage from aftershocks.

“Tuesday’s earthquake left us with no option but to immediately stop power generating operation by all 10 turbines (each of 100MW). We did it keeping in view appearance of silt and sediments in the water that cannot be used for power generation,” Wapda Chairman retired Lt Gen Muzammil Hussain told Dawn.

Upper-Jhelum canal shut to avoid any damage due to expected aftershocks

He said silt starts moving fast during an “earthquake-like situation”, making the water muddy. The use of muddy water can be devastating for power generating turbines. Therefore, it is necessary to thoroughly check the behaviour, seepage, sediments at the reservoir before resuming power generation.

“Therefore, it was necessary to wait till the sediments started settling down,” Mr Hussain said.

Meanwhile, a spokesperson for Wapda said after the suspension of power generation that there was no damage to Mangla reservoir and power station, adding that all the 10 turbines were shut only as a precautionary measure. “Power generation at Mangla has been shut as a precautionary measure since the operation cannot be continued due to muddy water. As soon as the water appears clean, power generation will restart,” he explained.

The first two units (turbines) of Mangla station were commissioned in Aug 1967, followed by the third in March 1968, the fourth in June 1969, the fifth in Dec 1973, the sixth in March 1974, the seventh and the eighth in 1981, the ninth in Sept 1993 and the tenth in July 1994.

Mangla has a capacity to generate 1,150MW _ 150MW above its rated capacity of 1,000MW _ during the higher reservoir level period while the capacity shrinks to 496MW in the lean flow period (winter season) due to reduction in the reservoir’s water level.

Instructions for train drivers Pakistan Railways has instructed its drivers to observe slow speed while passing through Jhelum, Dina and Kharian.

“Teams have been deputed to check condition of the main line, especially between Lahore and Rawalpindi, and submit a report to the department concerned,” said an official source.

Published in Dawn, September 25th, 2019