The cost of making Copenhagen Municipality safe when extraordinary cloudbursts occur has been seriously underestimated.
Up until now, three proposed tunnels – provisionally named Svanemølle, Valby and Vesterbro – have been budgeted to cost 1.6 billion kroner.
Budget costs awash
However, a note sent to Copenhagen’s municipal technical and environmental committee has revealed that another 2.4 billion kroner will be required to complete the three large tunnels designed to cope with the excess water that falls during a cloudburst, reports Ingeniøren.
The reason given for the cost overrun is that when the project was initially conceived, the amount of water that the tunnels were expected to handle was much less than current predictions indicate will be necessary.
Larger water bills
The extra costs will be shared by the three companies behind the project: Hofor, Frederiksberg Forsyning and Novafos.
According to the note, the cost overrun will mean that water tariffs will increase for consumers by around 40-50 øre per cubic metre of water. For a household consuming 110 cubic metres of water per year, that would equate to between 44 and 55 kroner per annum.
Despite the cost, the project could still pay dividends. The large tunnels might mean that money could be saved on other flood-prevention projects above ground because the tunnels cover such a large area.