The DKr490m (£55.8m) contract will be carried out on behalf of Greater Copenhagen utility company Hofor and local utility company Frederiksberg Forsyning.
The tunnel will protect Valby, one of the 10 districts of Copenhagen municipality, and the western part of Frederiksberg against flooding caused by cloudbursts and high rainfall.
The tunnel will support the sewage network by collecting overflow water from the sewer system until the water can be pumped to the sewage treatment plant. In cases of extreme rain, water may also be conveyed directly into Kalveboderne through outlets in Gåsebæksrenden and Enghave Kanal through a pumping station.
The 2.4km-long bored tunnel will have an internal diameter of 3.4m, providing the capacity to manage 100-year rain events.
The tunnel will have a 30,000m3 capacity and is among the largest of several wastewater projects planned for Frederiksberg and Copenhagen.
Work will start this year with four construction sites and shafts, and the project is scheduled for handover to the utility companies in 2028.
“An assignment of this scope is very demanding for the contractor, and MT Højgaard Danmark and our partner Eiffage Infra-Spezialtiefbau have both the experience and competencies from comparable projects completed over the years. We really look forward to completing this task as well,” said MT Højgaard Danmark CEO Carsten Lund.
In April, TBM Sigrid completed boring on the Kalvebod Brygge tunnel, which will protect eastern Frederiksberg and Vesterbro from flooding.
TBM Sigrid excavated 702m from Kalvebod Brygge to Halmtorvet in Copenhagen as part of the 1.3km-long Kalvebod Brygge Skyburst tunnel, which runs from Gammel Kongevej to Kalvebod Brygge and forms a central part of the protection of eastern Frederiksberg and Vesterbro. It is due to be commissioned in 2026.
