Tarbela T-5 project halted after tunnel flooding

HARIPUR: Construction work on the Tarbela Fifth Extension Hydropower Project has been suspended indefinitely after a protective bund collapsed on Monday, allowing a large volume of water to enter Tunnel Five.

Haripur Deputy Commissioner Waseem Ahmed confirmed the incident during a visit to the project site. He said the breach in the protective structure resulted in flooding inside the tunnel, prompting an immediate response from the district administration and rescue agencies.

All Pakistani and foreign workers were evacuated to a safe location following the incident. One Pakistani worker was swept away by the rising water but was rescued by emergency personnel. No casualties were reported.

The deputy commissioner said work on the project had been halted indefinitely, while an investigation was underway to establish the cause of the incident.

He added that a high-level inquiry would examine the circumstances behind the failure of the protective bund and determine whether a structural weakness or technical fault was responsible.

The administration will decide on the resumption of construction activities after receiving the investigation report, Ahmed said.

The affected construction site is part of the Tarbela Fifth Extension Hydropower Project, a major Water and Power Development Authority (WAPDA) initiative being developed at Tunnel Five of Tarbela Dam.

The project is designed to increase the dam’s electricity generation capacity by 1,530 megawatts through the installation of three generating units, each with a capacity of 510MW.

In May 2021, WAPDA awarded a $354.6 million civil works contract to China’s Power Construction Corporation. The project has an approved cost of $807 million, with $390 million in financing from the World Bank and another $300 million from the Asian Infrastructure Investment Bank.

Upon completion, the extension is expected to produce an average of 1.347 billion units of electricity annually. It will raise Tarbela Dam’s installed generation capacity from 4,888MW to 6,418MW.

However, the project has encountered several setbacks, resulting in repeated delays. Initially planned for completion within five years, its deadline has been extended to September 2027.

In September 2024, a project director informed a Senate committee that difficulties in obtaining a no-objection certificate from the Indus River System Authority (IRSA) for closing Tunnel Five were among the factors affecting progress.

Construction activities were also temporarily suspended in August 2025 after rising reservoir levels and increased water inflows caused flooding at the project site.

Monday’s incident has raised further concerns about the project’s construction timeline, with its future progress now dependent on the findings of the official investigation.