Rock collapse at Tarbela T5 sends water into tunnel, work stopped
- WAPDA denies reports of tunnel collapse
Construction at Pakistan's Tarbela Fifth Extension Hydropower Project was suspended after water entered Tunnel No. 5 due to a rockfall. An inquiry is underway, but no major damage or casualties were reported.
- Details of the incident and WAPDA's official statement.
- The ongoing inquiry into the cause of the tunnel incident.
- Project's funding, capacity, and history of delays.
Construction work at the Tarbela Fifth Extension (T5) Hydropower Project was suspended on Monday after water entered Tunnel No. 5. All Pakistani and foreign staff were moved to safety.
Aaj News reported that a crack in the project’s protective embankment let a large volume of water flow into the tunnel.
Haripur Deputy Commissioner Wasim Ahmed visited the site with rescue and administrative teams and confirmed that water had entered the tunnel.
One Pakistani worker was swept away by the current as the tunnel filled, but rescue teams saved him. No casualties have been reported.
The Water and Power Development Authority (WAPDA) rejected reports that Tunnel 5 had collapsed.
A WAPDA spokesperson said a weak section of rock fell while workers were excavating the second bench of the connecting tunnel. This let water into the tunnel and the powerhouse area.
WAPDA said the intake pit has been fully drained and water is still being pumped out of the under-construction powerhouse. No more water is entering the construction sites.
The authority said the main tunnel, powerhouse, tailrace culvert and switchyard were not damaged. Senior WAPDA officials, project consultants and contractors are at the site reviewing safety measures and deciding on next steps.
Officials have opened an inquiry into what caused the incident. A high-level committee will look at whether structural weakness or a technical fault was to blame. Work will resume based on the committee’s findings.
The T5 project will add 1,530MW through three 510MW units. This will raise Tarbela’s installed capacity from 4,888MW to 6,418MW. It is expected to generate an average of 1.347 billion units of electricity a year.
The project’s approved cost is $807 million. The World Bank is providing $390 million and the Asian Infrastructure Investment Bank (AIIB) $300 million. In May 2021, WAPDA awarded the $354.6 million civil works contract to Power Construction Corporation of China.
The project has already faced delays, and its completion deadline has been pushed to September 2027. In 2024, difficulties arose in obtaining a No Objection Certificate from the Indus River System Authority (IRSA) to close the tunnel. Work was also halted for a time in August 2025 when the reservoir level rose.