Ole-Petter Nilsen from the Water and Wastewater Administration in Oslo Municipality says the new water tunnel across Oslo will probably secure the capital's water for more than 100 years. Oslo is one of Europe's fastest growing cities and the facility will also meet the needs of the people of the future.  Population of Oslo is currently 690,000 inhabitants, in 20 years it is expected to increase to 839,000.

The main tunnel will have a diameter of 6-7 metres.

Today, Oslo's water supply is entirely dependent on Maridalsvannet and Oset water treatment plants, which supply 90 per cent of the drinking water in the capital. The Norwegian Food Safety Authority has ordered the City of Oslo to have additional and alternative water source and water treatment plants by January 1, 2028.

The main work includes a new raw water tunnel, a new water treatment plant and a clean water tunnel that will distribute drinking water in Oslo. In addition, it is planned to build parts of a grid for distribution of drinking water to be completed at the same time as the new water treatment plant.

https://www.tu.no/deltav/bygg/annonse-skal-bygge-tunnel-under-oslo-pa-tvers-slik-blir-den-nye-hovedpulsaren-som-skal-sikre-vannforsyningen/486175

#Norway.

Project is getting traction. Water and Wastewater Agency has organized a web meeting on May 5, 2020 from 15:00 till 16:30. This is information meeting and it will be hosted by Akersposten newspaper. Everyone can place questions over Oslo's new water supply project.

The project has been approved in November 2019 by the city council of Oslo for a budget of NOK 12.5 billion. The City of Oslo is responsible for the project, which is scheduled to be completed by the end of 2027.

As I had written before (above), the 19km long tunnel will be bored with two TBMs (tunnel boring machines), one from each side.

Begin April the news came that the company Skanska had been nominated as contractor for blasting of access tunnels and mountain halls. Per plan, in the summer of 2020, the rigging of construction sites at Hyseby will start. 

I am not sure about the boring tunnel contractor. I am sure, it is not determined yet. If you like, you can ask them during the web meeting or you can send email to postmottak@vav.oslo.kommune.no and ask.

https://akersposten.no/viktig-a-fa-pa-plass-gode-tiltak-for-a-gjore-arbeidet-mindre-til-plage-for-narmiljoet/19.4966

First milestone contract for the work on a new water supply to Oslo has been signed between the Municipality of Oslo (Sewerage Authority) and Skanska in the morning of 14 August reports Akersposten. This is an indication that the construction work in the project new water supply Oslo will start soon.

Skanska will construct 2 access tunnels and an overflow tunnel (total 5km) in the west of Oslo. Contract value is NOK 2.88 billion. This is the first of eight large contracts for construction work in what is Norway's largest water and wastewater project with an estimated cost of NOK 12.5 billion.

https://akersposten.no/1-2-millioner-kubikk-fast-fjell-skal-tas-ut/19.5430

Norway's international engineering consultancy and design company Multiconsult gets the design work for the E6 Clean Water Tunnel of Oslo's new Water Supply Tunnel.

https://tunnelcontact.com/discussion/view/24808/oslo-water-supply-tunnel-multiconsult-gets-e6-clean-water-tunnel-design-work

Oslo delays the awarding of the new raw water tunnel. Bids are still in evaluation.

https://tunnelcontact.com/discussion/reply/view/30686/30684#elgg-object-30686