Construction on the World Bank-funded Tarbela 5th Extension Hydropower Project has been suspended indefinitely following a catastrophic breach of a protective bund on Monday. The failure allowed a large volume of water to flood Tunnel Five, necessitating the evacuation of both Pakistani and foreign workers from the site.
Emergency teams rescued one worker who was swept away by the water. According to Dams for Electricity Generation Sources, all workers were moved to safety and no casualties were reported.
The district administration has initiated an investigation to identify the cause of the breach. A high-level inquiry will specifically examine if a technical fault or structural weakness caused the failure. Authorities stated they will determine the next steps once the investigation report is received.
The project is a Water and Power Development Authority (WAPDA) scheme intended to expand electricity generation at Tarbela Dam. It aims to add 1,530 megawatts of capacity through three units, each capable of producing 510MW. Upon completion, the dam's installed capacity would rise from 4,888MW to 6,418MW.
The project has an approved cost of $807 million, with the World Bank providing $390 million and the Asian Infrastructure Investment Bank contributing $300 million. In May 2021, WAPDA awarded a $354.6 million civil works contract to China’s Power Construction Corporation.
While originally scheduled for a five-year completion period, repeated delays moved the deadline to September 2027. These delays included years of difficulty obtaining an NOC from the Indus River System Authority (IRSA) to close Tunnel Five. Construction was also temporarily halted in August 2025 due to flooding caused by rising reservoir levels and increased water inflows.
