City of Copenhagen

Preventing flooding with urban spaces

The devastating floods that hit Belgium, the Netherlands and Germany last year caused incalculable human and material damage. In addition to the loss of lives, the destruction of homes and cities’ infrastructures, there’s increasing fear that episodes like these may be repeated, particularly in the face of climate change.

Elsewhere in Northern Europe, heavy rainfalls and rising sea levels have caused death and destruction in Copenhagen in the past and with climate change they remain a constant threat the city needs to contend with.

The Danish capital’s Cloudburst Management Plan is designed to reduce this risk while improving urban liveability, social inclusion and biodiversity. The system “shall protect Copenhagen from future heavier rainfall,” explains Jan Rasmussen, Copenhagen’s Project Director of the Center for Climate Adaptation. 

The projects implemented so far have been a great success
— Jan Rasmussen

Cloudburst’s long-term plan is the creation of some 300 areas that can serve as recreational spaces when it doesn’t rain and double-down as water collectors in stormy weather. These green and biodiverse sites are being built all over the city in areas where water can be collected or discharged, preventing it from causing flooding or from overwhelming the sewage system.

Locals can enjoy themselves in these newly created public spaces such as skateparks or playing fields. Whenever storms threaten the city, these areas immediately turn into reservoirs; rainwater gathered here is then stored elsewhere or siphoned out of the city.

So far, Copenhagen has completed the construction of nine new areas of this type; 66 other sites are in the design or planning phase and will be implemented in the coming years. All are co-designed with the involvement of locals to ensure that they meet their needs and preferences.

Photo by Anders Pedersen

“The projects implemented so far have been a great success. They meet two goals: they secure the city against cloudbursts and create more recreational green urban spaces,” says Rasmussen.

The schemes are based on Copenhagen’s climate adaptation and cloudburst plans that aim to gear up the Danish capital for future environmental threats while creating more green spaces in town. “The goal is to look at climate change from a 100-year perspective and adapt the city to the climate in synergy with urban development,” Rasmussen explains.

For years, Copenhagen has been working to reduce overflows from its sewer system, improve areas prone to flooding and introduce changes such as the possibility to swim in the port.

In the long run, all these measures will improve environmental conditions in the city’s water bodies and increase biodiversity.

The participation of local communities is fundamental. Workshops, working groups and other initiatives are designed to engage citizens so they can have a feeling of ownership and care for the newly created green spaces.

Eurocities Awards winners, Copenhagen

Surmounting hurdles

Naturally, the city faced setbacks during the implementation of Clouburst.

The goal is to look at climate change from a 100-year perspective and adapt the city to the climate in synergy with urban development
— Jan Rasmussen

Rasmussen notes that the “construction of green climate adaptation projects challenged existing practices in a wide range of areas, including legislation on rainwater management, cooperation within the municipality and with external parties participating in the implementation.”

“It is also a particular challenge that there are no national or international standards and methods for the planning, implementation and operation of nature-based rainwater solutions,” he adds.

Financial issues were solved by a change in the law allowing the city to charge a water tariff through its partner, the Greater Copenhagen Utility.

In addition, to prevent damages that excess water could cause to plants and the proliferation of mosquitos, Copenahgen developed a solution where water is only retained for a short period of time on the surface.

Despite the hurdles, Cloudburst’s success can easily be seen. More recently, Copenhagen won two 2021 Eurocities Awards: it ranked first in the ‘planning public spaces’ category and secured Eurocities members’ vote in a special extra category created last year.

The Danish capital’s initiative sets an example to other cities all over Europe for its ambitious goals, excellent results and legacy to its citizens.

Raphael Garcia Eurocities Writer