The 4.5m diameter tunnel will extend between the Al Khuwaytim and Birkat Al Awamer areas and carry flows from the city of Al Wakra and town of Al Wukair to the Al Wakra and Al Wukair Sewage Treatment Works. The gravity tunnel, which has a 100-year design life, is one of the largest drainage tunnels in Qatar.
Excavation is being carried out by two TBMs at a depth of about 60m.
The project includes the construction of eight shafts, with depths ranging from 50 to 63m.
As well as the main drainage tunnel, there are two additional packages: the drainage networks branches, and the treated sewage effluent lines in Al Wakra and Al Wukair.
The total length of the network branches is around 15km and the system comprises smaller tunnels with diameters ranging from 400mm to 2400mm and at a depth from 9m to 46m. The network will be built using micro-tunnelling techniques through 60 shafts.
The treated sewage effluent lines have a total length of approximately 29km and diameters ranging from 600mm to 1400mm.
The total cost of the project is more than QR1.5 billion (US$412m). It is the first project in Qatar to be financed through a Public-Private Partnership. The contractor is PORR-HBK-MIDMAC JV and Parsons International Ltd is responsible the design, implementation and operation of the project.
The scheme is scheduled for completion in the second quarter of 2024.
* Meanwhile, Iran has raised the idea of connecting to Qatar by building what would be the world’s longest tunnel.
According to Iranian media reports, the tunnel will be one of four agreements signed when Iranian and Qatari ministers meet in Doha this week. The proposed tunnel would connect the Iranian port town of Dayyar to Qatar.
