SWABI: A rock mass collapsed at the Tarbela Dam 5th Extension Project construction site on Monday, causing a surge of water to enter downstream work areas.

An emergency was declared following the collapse, construction work was suspended and workers were directed to move to safer areas.

The Water and Power Development Authority (Wapda) said in a statement that water entered the under-construction power house area and a tunnel of the Tarbela Dam 5th Extension Project after a weak rock mass collapsed during excavation work, prompting the evacuation of workers.

In a statement, Wapda said the incident occurred during excavation of the 2nd Bench Connecting Tunnel, when the collapse allowed water from the Intake Pit to enter the tunnel and power house area.

“All workers were immediately evacuated safely,” the statement said, adding that the water from the Intake Pit had been completely drained and no further water was entering the downstream work sites.

Wapda said dewatering work at the under-construction power house had also started.

Senior Wapda officers, the project engineer and the contractor were assessing the situation to address any challenges to the T-5 project, the statement added.

The authority also dismissed reports circulating about the collapse of the T-5 tunnel, saying the main tunnel, under-construction power house, tailrace culvert and switchyard had not been damaged.

It further said there had been no injuries or loss of life among the workforce.

More to follow.