Construction work on Pakistan's Tarbela 5th Extension Hydropower Project (T-5) has been suspended indefinitely after a rock collapse sent water flooding into a tunnel and the under-construction powerhouse on Monday, 9 November. All workers were evacuated safely and no casualties were reported, the Water and Power Development Authority (WAPDA) said.

The incident happened during excavation of the project's Second Bench Connecting Tunnel, when a weak section of rock gave way and water from the intake pit poured into the tunnel and the powerhouse area. Haripur Deputy Commissioner Waseem Ahmed, who visited the site, said all Pakistani and foreign workers had been evacuated and the situation was under control.

One local worker who was submerged as water entered the tunnel was pulled out alive by local people, the deputy commissioner said. WAPDA said no worker was injured or killed in the incident.

WAPDA rejects reports that Tunnel 5 collapsed

WAPDA moved quickly to correct reports circulating on social media that the main T-5 tunnel had collapsed. In a statement, the authority said the main tunnel, the under-construction powerhouse, the tailrace culvert and the switchyard had suffered no damage. It said water from the intake pit had been completely drained, no further water was entering the downstream work sites, and dewatering of the powerhouse had begun.

District officials also reassured residents downstream. A senior district administration official said there was no threat of flooding in areas below Tarbela Dam, and the dam structure itself was not affected. The incident was a construction accident at the extension works, not a failure of the dam.

Two accounts of what failed first have emerged. WAPDA attributed the inflow to the collapse of weak rock during excavation. The Haripur deputy commissioner initially said part of the protective embankment at the project intake broke after a girder fell. Neither account has yet been settled, and a high-level inquiry has been ordered to establish the cause.

Second flooding setback for the 1,530 MW project

The T-5 project is being built at Tunnel No 5 of Tarbela Dam, on the Indus River in Khyber Pakhtunkhwa, and is designed to add 1,530 megawatts of electricity to the national grid through three generating units of 510 MW each. It is one of Pakistan's largest power projects and is backed by the World Bank and the Asian Infrastructure Investment Bank.

Monday's flooding is the second time in about 15 months that water has interrupted work at T-5. In August 2025, work was temporarily suspended after rising reservoir levels sent water into the construction site. The project has already faced repeated delays, with its overall completion date slipping to September 2027, and WAPDA has not said what the latest incident will cost or whether that date will move again.

Officials said work would remain suspended until the inquiry reports and the site is declared safe. Until then, there is no date for construction to restart at one of the country's most important energy projects. Further updates are expected from WAPDA and the Haripur district administration as the investigation proceeds. For background on the project, see The News report on the evacuation and Daily Global South's account of the WAPDA statement.