Planning for this future, Copenhagen had to make a choice between two very different paths.

The first option was to expand the city’s existing subterranean sewer and drainage system—its “gray” infrastructure.” This would mean doubling down on the 20th-century notion that the city could handle higher volumes of rainwater as it falls by burying more and larger pipes to handle the runoff.

The second option was more of a “green and blue” system. Rather than funneling all stormwater at once through underground pipes, this option envisioned dealing with water at street level through a network of parks, cloudburst boulevards and retention zones.

Copenhagen opted for a Climate Adaptation Plan that relies mostly on the latter approach. In November, the council unanimously approved plans for 300 surface-based solutions like those in Tåsinge Plads to be implemented over the next 20 years. “The ambition of the Climate Adaptation Plan is to get technical solutions above ground,” says René Sommer Lindsay, manager for project in the neighborhood around Tåsinge Plads.  “So when it’s not raining, there is still value in the space.”

Why Copenhagen Is Building Parks That Can Turn Into Ponds