SWABI: A rock mass collapsed at the Tarbela Dam 5th Extension Project (T-5) construction site on Monday, causing a surge of water to enter nearby work areas, said the Water and Power Development Authority (Wapda).

An emergency was declared following the collapse; construction work was suspended and workers were directed to move to safer areas. However, no loss of life was reported in the incident.

In a statement, Wapda said that water entered the under-construction power house area and a tunnel of the T-5 project after a weak rock mass collapsed during excavation work, prompting the evacuation of workers.

The authority 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.

Authorities were assessing whether the tunnel, power house and other structures in the working area had sustained any damage, Deputy Commissioner Haripur Waseem Ahmed said, quoting officials of the T-5 project.

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.

There is no threat of flooding or inundation in areas downstream of Tarbela at present, a senior district administration official said.

Meanwhile, Swabi Deputy Commissioner Nasarullah Khan said that additional water had been released from Tarbela Dam due to “unavoidable” reasons and was expected to increase the flow and level of water in the Indus River.

“All citizens are requested to take precautionary measures and completely avoid bathing, swimming and boating in the Indus River to prevent any untoward incident,” he said.

The deputy commissioner also urged the public to ensure their own safety and that of their families and follow public safety notices.

“Citizens should not pay heed to rumours and should visit our official page for authentic information,” Khan added.

Earlier in July, a government-constituted inquiry committee held all three key stakeholders — the contractor, consultant and employer (Wapda) — responsible for the cofferdam collapse at the 1,530MW T-5 Project, citing post-contract unauthorised design changes as one of the main reasons for the incident.

The collapse contributed to at least a two-year delay and more than 285 per cent cost escalation in the project, whose cost has risen from Rs82 billion to Rs317bn.

The project was scheduled for completion by the end of June 2028, instead of 2026, before Monday’s incident.

The fifth extension project has an installed capacity of 1,530MW. The World Bank and the Asian Infrastructure Investment Bank are providing $390 million and $300m respectively for its construction. Once completed, Tarbela’s total installed capacity will rise from 4,888MW to 6,418MW.