Workers at Pakistan’s Tarbela Dam fifth extension project were pulled out of the tunnel and powerhouse area after water broke into the construction site, forcing work to stop on one of the country’s biggest hydropower expansions.
A breach in a protective embankment at the Tunnel Five project in Khyber Pakhtunkhwa province triggered a flood, and officials halted construction. Pakistan media reports give a slightly different account of the cause. A weak rock mass collapsed during excavation of a connecting tunnel, and water from the intake pit entered the tunnel and the powerhouse area, prompting an emergency evacuation. The precise cause is still being assessed.
The Water and Power Development Authority (WAPDA) said all workers were safely evacuated and no injuries or deaths were reported. It added that the main tunnel, powerhouse, tailrace culvert and switchyard were not damaged, and dewatering has begun. One report differs on a detail. According to IANS, one Pakistani worker was swept into the water as the tunnel flooded and was rescued by emergency teams, with no casualties.
The project and who is building it
The fifth extension is planned to add 1,530 megawatts through three 510MW units, lifting Tarbela’s installed capacity from 4,888MW to 6,418MW and generating an average of 1.347 billion units of electricity a year. The project is Pakistani, owned by WAPDA, but the main contractor is Chinese. The main construction is handled by China’s Power Construction Corporation of China. It is financed partly through loans from the World Bank and the Asian Infrastructure Investment Bank.
A project already in trouble
This is not the first failure. The latest incident comes months after a cofferdam collapse at the same project. A government inquiry blamed unauthorised design changes and contractual failures involving the contractor, consultant and WAPDA. That collapse delayed the project by at least two years and raised the estimated cost by more than 285%, from PKR 82 billion to PKR 317 billion. Completion is now scheduled for June 2028 instead of 2026. The inquiry’s findings put responsibility on the contractor, the consultant and WAPDA together, not on the Chinese firm alone.
Security concerns around Chinese workers
The site has had other problems. Work stopped for five days after a suicide attack on a Chinese convoy in Shangla district killed five Chinese engineers and a Pakistani driver, and more than 2,500 workers were told to return afterwards, with heightened security. Chinese-run projects across Pakistan have been targets of militant attacks, which is why safety on them draws close scrutiny from both governments.
WAPDA is assessing the impact of the flooding on the schedule. Videos of the collapse have gone viral on social media. The key questions are what caused the failure, whether it traces to the same design and oversight lapses the earlier inquiry found, and whether the June 2028 deadline can hold.
