Flood defences to help create greener city

New rivers and parks will be designed to alleviate pressure on the sewer system that cannot cope with the sudden volume of water during heavy downpours

New infrastructure to handle heavy rain and downpours in Copenhagen was agreed upon by City Council this week, reports Politiken newspaper.

The Technical and Environmental Administration (TMF) decided against expensive solutions such as tunnels and instead opted for surface infrastructure to absorb and divert excess water.

“The surface solutions are recommended because they have the lowest costs, have the greatest robustness to climate change and give the greatest added value through a greener city and the opportunity to increase traffic safety for pedestrians and cyclists,” TMF stated.

READ MORE: City Council taking new look at old stream

New rivers
Among the infrastructure plans is the construction of a stream alongside the central traffic artery HC Andersen Boulevard and a new park by the inner city lake Sankt Jørgens Sø.

Both would flood during heavy downpours thereby diverting water that would otherwise flood streets and basements, which can cause heavy damage.

READ MORE: 2.5 billion kroner promised to prevent flooding

One particularly devastating downpour in July 2012 caused five billion kroner of damages after 150 millimetres of rain fell in three hours and turned streets into rivers (the event was captured in the video below).

Greener city
The city's deputy mayor for technical and environmental affairs, Ayfer Baykal (Socialistisk Folkeparti), said the plan demonstrates how to create a greener city using flood defences.

“This was one of the most significant demands we heard from the local committees and the many Copenhageners who participated in the hearing process,” Baykal told Politiken.

READ MORE: Drenched

The council expects that the infrastructure improvements – which will be divided into three separate plans – will cost three billion kroner and take 20 years to complete.

The majority of the costs will be derived from increased water bills, with the average apartment paying an additional 50 kroner a month and villa 75 kroner a month.