Tarbela Dam's 5th Extension Project Suspended Indefinitely After Rock Collapse Triggers Major Water Inflow

VoS NEWS DESK | PAKISTAN | 10 NOVEMBER 2026

ISLAMABAD: Pakistan's major hydropower development project at Tarbela Dam has suffered another serious setback after a rock mass collapsed during construction work, allowing a large volume of water to enter the tunnel and under-construction powerhouse areas. The incident prompted authorities to suspend construction activities indefinitely and launch an assessment of the affected site.

The incident occurred on Monday during excavation work at the Tarbela Dam 5th Extension Hydropower Project, commonly known as T-5. According to the Water and Power Development Authority (WAPDA), a weak section of rock collapsed during excavation of the second bench of the connecting tunnel. The collapse allowed water from the intake pit to enter the tunnel and powerhouse area, creating an emergency situation at the construction site.

Following the incident, workers were immediately instructed to move to safer locations. WAPDA confirmed that all workers were evacuated safely and that no injuries or fatalities were reported. The authority also clarified that reports suggesting the collapse of the main T-5 tunnel were incorrect.

In its official statement, WAPDA said that water from the intake pit had been completely drained and that no further water was entering the downstream construction areas. Dewatering operations at the under-construction powerhouse had also commenced, while senior WAPDA officials, project engineers and the contractor began assessing the situation to determine the extent of the disruption.

The authority further maintained that the main tunnel, under-construction powerhouse, tailrace culvert and switchyard had not sustained damage. However, construction activities remain suspended indefinitely as officials evaluate the technical situation and determine the necessary measures before work can resume.

Increased Indus River Discharge Prompts Safety Alert

The incident has also raised concerns about water flow in the Indus River after authorities increased releases from Tarbela Dam. According to reports, water discharge increased from approximately 55,000 cusecs to 144,200 cusecs, with officials indicating that the flow could remain around or above 150,000 cusecs.

The Provincial Disaster Management Authority (PDMA) issued an alert to the administrations of Haripur, Swabi and Nowshera, directing them to take precautionary measures and maintain close monitoring of communities situated along the riverbanks.

District administrations have been instructed to remain vigilant, particularly in vulnerable areas where increased river flows could create safety concerns. Residents have also been advised to avoid unnecessary activities near the river, including swimming, bathing and boating, and to follow official instructions.

Authorities have emphasised that there is currently no indication of a breach in the main Tarbela Dam. Officials have also urged the public not to believe misleading social media reports claiming that the entire dam or its main tunnel has collapsed.

Major Hydropower Project Faces Further Delays

The latest incident represents another setback for the Tarbela 5th Extension Hydropower Project, one of Pakistan's important ongoing electricity-generation developments. The project is designed to add 1,530 megawatts of installed generation capacity through three generating units, each capable of producing 510 megawatts.

Once completed, the extension is expected to increase Tarbela Dam's total installed electricity-generation capacity from 4,888MW to 6,418MW, strengthening Pakistan's ability to generate electricity through hydropower.

The project is supported by international development financing, including $390 million from the World Bank and $300 million from the Asian Infrastructure Investment Bank. Its construction has already experienced substantial delays and rising costs.

Earlier, a government-constituted inquiry committee held WAPDA, the contractor and the consultant responsible for issues surrounding an earlier cofferdam collapse, identifying unauthorised post-contract design changes among the contributing factors. The project has also faced significant cost escalation, with its estimated cost rising from approximately Rs82 billion to Rs317 billion.

The latest water-inflow incident has therefore renewed attention on construction safety, engineering supervision and project management at one of Pakistan's most strategically important hydropower facilities.

Investigations and technical assessments are expected to determine the circumstances behind the latest incident and the measures required to prevent similar disruptions. The resumption of construction will depend on the findings of the ongoing assessment and the ability of the project authorities to ensure safe working conditions.

VoS STRATEGIC INSIGHT

The latest setback at Tarbela highlights the challenges facing Pakistan's long-term energy infrastructure development. With electricity demand continuing to place pressure on the country's power system, delays in major hydropower projects can have wider implications for energy planning, generation capacity and economic stability.

The additional 1,530MW planned under the T-5 extension represents an important contribution to Pakistan's future electricity supply. However, repeated construction disruptions, rising costs and engineering concerns demonstrate the importance of stronger technical supervision, independent safety assessments and transparent accountability.

Beyond the immediate incident, the priority must remain the protection of workers, the safety of downstream communities and the timely completion of critical national infrastructure. Pakistan's hydropower ambitions will require not only financial investment but also consistent engineering standards and effective project management.