Rock collapse floods work sites at Tarbela project

The breach also caused an increased flow of water in the River Indus, with authorities issuing an alert for the areas adjoining the river. the Water and Power Development Authority (Wapda), a weak rock mass collapsed during excavation of the 2nd Bench Connecting Tunnel, causing water from the Intake Pit to enter the tunnel and the powerhouse area.

"The water from the Intake Pit has been completely drained, and no further water is entering the downstream work sites," the statement said, adding that dewatering from the under-construction powerhouse had started. The authority said all workers were immediately evacuated safely following the incident, reporting no casualties.

Wapda stated that senior officers, the engineer, and the contractor were assessing the situation to address any challenges to the T-5 project. The statement also debunked circulating information about the collapse of Tunnel Five: "There is no damage to the main tunnel, under-construction powerhouse, tailrace culvert or switch yard.

Reports of tunnel collapse are incorrect. " the Tarbella Dam authorities, the inflow of water in the River Indus was expected to reach 150,000 cusecs in the next 24 hours. It directed all relevant departments, district administrations and the public to take necessary precautionary measures due to possible risks.

It also advised the public to avoid going near the banks of the River Indus and to refrain from bathing, swimming or boating in the river. The notification urged parents to keep children away from the river and streams, and people to keep their livestock away from areas with strong water currents.

In case of an emergency, the relevant authorities should be informed immediately, it said. It advised the people of Swabi to ensure their own safety and that of their families and to follow the instructions issued by the administration.

Haripur Deputy Commissioner Waseem Ahmed visited the site following the incident and confirmed that water had entered the tunnel after the protective embankment gave way. He said the administration and rescue agencies had promptly evacuated all Pakistani and foreign workers—present at the site—to a safe location following the breach.

Ahmed said one Pakistani worker was swept into the water as the tunnel flooded but was rescued by emergency teams, adding that no casualties had been reported. He said construction and development work on the T-5 project had been suspended indefinitely following the incident, while an investigation had been launched to determine the cause of the breach.

Ahmed further added that a high-level inquiry would examine the circumstances surrounding the failure of the protective embankment and establish if a structural weakness or technical fault had caused it. "The next course of action will be determined after the investigation report is received," he added.

The construction work was part of the Tarbela 5th Extension Hydropower Project, a major Wapda scheme being built at Tunnel Five of Tarbela Dam. The project was planned to add 1,530 megawatts to the dam's installed generation capacity through three units of 510MW each.

Wapda awarded a $354.6 million contract for the project's civil works to the Power Construction Corporation of China—POWERCHINA—in May 2021. The project had an approved cost of $807 million, with the World Bank providing $390 million and the Asian Infrastructure Investment Bank contributing $300 million.

Once completed, it was expected to generate an average of 1.347 billion units of electricity annually and increase Tarbela Dam's installed capacity from 4,888MW to 6,418MW. The project has faced repeated delays, pushing its completion deadline back from the original five-year schedule to September 2027.

In September 2024, a project director delays had been caused, among other factors, by difficulties in obtaining an NOC from the Indus River System Authority (IRSA) for the closure of Tunnel Five. The project had also faced a temporary suspension in August 2025 after rising reservoir levels and increased water inflows led to water entering the construction site.