Like many cities, Copenhagen has to think about managing increasing volumes of water. Over the long-term, it faces the threat of rising sea levels (especially because the city is a harbor). More immediately, it has to deal with extreme weather events, like the storm that dumped six inches of rain in three hours in the summer of 2011. That cloudburst alone left $1 billion worth of damages, and showed how traditional infrastructure is insufficient in the age of climate change.
“That monster rain incident is normally something you would have only once every thousand years. It was hugely devastating for the whole of Copenhagen,” says Flemming Rafn Thomsen, co-founder of Tredje Natur (“Third Nature”), a local design firm. “There’s only so much you can do with sewers when it comes down to it. They have a fixed capacity and enlarging them is a very expensive and tiresome process.”
Firms like Tredje Natur are therefore looking at above-ground alternatives, like the redesign Rafn Thomsen has engineered.
The redevelopment, in the Saint Kjeld part of Copenhagen, features a host of ideas for diverting and/or collecting water, so it doesn’t do harm to buildings and amenities. There are pools to gather water from nearby rooftops, grooves in walkways to carry water away to a local stream, more vegetation to soak up moisture, and water towers that fill up passively, serving as a water supply for urban agriculture.
Tredje Natur planned for the design by analyzing the topography of the area and seeing how water flowed. Then the designers identified spare space–about 20% of the total–that could be used for the new “blue infrastructure.” At the same time, they’ve put in more bike lanes, public seating and recreation. Most of the development is in Saint Kjeld’s Square and Tåsinge Square.
“We are going to see a very powerful transformation of our spaces in the coming years,” Rafn Thomsen says. More cities will effectively become “tidal”–in the sense they’ll allow water in and then control the flooding, he reckons. It makes more sense than always trying to keep water at bay, or underground.
At the same time, projects like Saint Kjeld are also “learning landscapes.” They teach us about our relationship with the environment.
“We are creating a more transparent city where we can see where the water goes,” he says. “Normally, you would have that in a rural setting. With this, you have a much bigger understanding of the network of resource relations that the city is part of.”