Tarbela T-5 project work suspended indefinitely after protective bund breach
HARIPUR: A breach in a protective bund at the Tarbela Dam’s T-5 hydropower project on Monday caused a large volume of water to flood Tunnel Five, prompting the suspension of construction work indefinitely, officials said.
According to a statement issued by the Water and Power Development Authority (WAPDA), during tunnel excavation of the 2nd Bench Connecting Tunnel, a weak rock mass collapsed, 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.
WAPDA said that senior officers, the engineer, and the contractor are currently assessing the situation to cater for any challenge to Project T-5.
The statement also debunked information circulating regarding the collapse of the T -5 Tunnel: “There is no damage to the main Tunnel, under-construction powerhouse, tailrace culvert or switch yard.”
Haripur Deputy Commissioner Waseem Ahmed earlier visited the site following the incident and confirmed that water had entered the tunnel after the protective bund gave way.
He said the administration and rescue agencies had promptly evacuated all Pakistani and foreign workers to a safe location following the breach.
One Pakistani worker was swept into the water as the tunnel flooded but was rescued by emergency teams, Ahmed said, adding that no casualties had been reported.
He said that 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 bund and establish whether a structural weakness or technical fault had caused it.
“The next course of action would be determined after the investigation report was received,” he added.
The construction work was part of the Tarbela 5th Extension Hydropower Project, a major WAPDA scheme being built at Tunnel No. 5 of Tarbela Dam. The project was intended 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 China’s Power Construction Corporation of China Limited 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, however, has faced repeated delays, pushing its completion deadline back from the original five-year schedule to September 2027. In September 2024, a project director told a Senate committee that 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 5.
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.