New Water Main is a Long-Distance Runner

In Southwestern Norway, a new water main for the Stavanger region will stretch more than 40 kilometres – nearly as long as a marathon race – connecting six municipalities.


When finished, the Olympic-distance water main will run between the treatment plant at Langevatn in Gjesdal and a reservoir at Tjensvoll in Stavanger. On the way, the pipeline passes a reservoir and 12-14 new valve chambers, which distributes water and regulates the water pressure. Speaking of water, the pipeline will be able to transport 3.300 litres of water per second – and fill up three and a half Royal Albert Halls – in 24 hours.    

The consulting group, COWI, is engineering the project on behalf of Interkommunalt Vann-, Avløps og Renovationsverk, IVAR; the inter municipal public water supplier for the Stavanger Region,

"We have collaborated with IVAR on previous projects and they run one of the most effective water supplies in the country," says Jon Håvard Lien, Project Manager at COWI.

Underwater engineering

Norway has an extensive water distribution system with 134.000 kilometers of pipelines serving the country's small and spread out population.

The current water main in the Southwestern Norway, also engineered by COWI, was finished in 1997 and measures 31 kilometres. The new, longer version will run west of the current one to maintain a steady municipal water supply, even in case of major leaks or maintenance work. COWI mobilizes a wide range of expertise to complete the project,

"We are a consulting group with a 360 degree approach and loads of different skills. In this case, we bring in our divers, surveyors, researchers, area planners and everyone in between. This enables us to handle the project, from the first design right up until the day when 40-kilometres of fresh, Norwegian tap water is flowing down the line," Jon Håvard Lien says.

The project has already taken off. According to the contract, the water main will be delivered in 2023.

Get in contact

COWI employee Søren Kragh Pedersen

Søren Kragh Pedersen
Head of Group PA & PR
Communication, Denmark

Tel: +45 2025 7018