New 11km tunnel will provide a resilient water supply for Oslo, marking a key milestone in Norway’s infrastructure.
A ‘Laila’ tunnel boring machine (TBM) has completed its work deep beneath Oslo, where it has bored the E6 water tunnel that will help supply drinking water to the Norwegian capital. The project forms part of SYSTRA’s strategic ambition to develop its activities in the adjacent water market.
The E6 project, also known as the Rentvannstunnel, reached a major milestone earlier this year with the final breakthrough by the Laila TBM. A factory train dug 11km under the bedrock of Oslo to build a key infrastructure for the capital’s authorities, who aim to make water transport and supply more reliable and robust.
The tunnel will draw water from Holsfjorden, west of Oslo, to a new underground water treatment facility at Huseby and distribute it across the Norwegian capital.
SYSTRA Italy, in partnership with Sweco Norge, is accompanying underground civil engineering studies on behalf of the AF Gruppen-Ghella consortium, including segments, technical and safety niches and tunnel boring machine launch structures. The tunnel will be connected to the nerve centre of Oslo’s new drinking water system.
Paolo Fantini, senior geotechnical engineer at SYSTRA Italy, said: “We are proud of the innovative and sustainable solution adopted for the TBM segmental lining design of Oslo’s E6 clean water tunnel. This 11km tunnel will provide a resilient and reliable water supply for the capital, marking a key milestone in Norway’s infrastructure security.”
In addition to the TBM drive, the project includes about 7km of drill and blast tunnels that connect to the existing facilities, including the network associated with the Maridalsvannet water treatment plant, which currently supplies roughly 90% of Oslo’s potable water.
Once complete, Oslo’s upgraded clean-water system will strengthen east–west distribution, access larger reservoirs and provide full back-up capacity for the city, improving resilience in case of issues with the existing supply.
