In July 2011 the city of Copenhagen experienced its worst cloudburst in 400 years. A cloudburst is a sudden downpour of unusually large quantities of rain in a limited period of time in a given area. For the Danish Meteorological Institute (DMI), 15mm of rainfall within 30 minutes is defined as a cloudburst.   The 2011 cloudburst inundated Copenhagen with 152.4mm of rain in less than three hours, flooding cellars, streets, key roads, several municipal buildings and sports centres. The entire deluge caused DKK 6 billion (US$1.04 billion) in damages.  In 2014 a cloudburst of similar intensity hit the Copenhagen and Malmø regions. Fortunately, the cloudburst only affected the northern outskirts, missing the city centre. 

The Intergovernmental Panel on Climate Change predicts that this sort of extreme weather will become increasingly frequent in Denmark, with heavier downpours as well as more periods of drought. Sea-level rise is a separate but related threat. According to research from the Niels Bohr Institute, the waters around Copenhagen could rise by up to 1.6 meters (more than 5 feet) in the next 100 years.

Subsequently, the City of Copenhagen has embarked on an agressive climate adaptation strategy, including the formation of Denmark’s first Climate Resilient neighbourhood, St Kjelds. The neighbourhood of St. Kjelds is diverse and densely populated with few green areas. The district houses 24,000 residents and more than 10,000 jobs are concentrated in an area of one square kilometer. The Climate-Resilient Neighbourhood initiative is part of Copenhagen's overall strategy for district and urban renewal that was initiated in 2010 through the Copenhagen Climate Adaptation Plan. St. Kjelds was selected as a pilot neighbourhood where methods and technologies for the adaptation to climate change would be developed. Many streets, squares and green areas required a physical upgrade, whereas wide streets and large asphalt areas offered potential for urban redevelopment. The aims of this project included practical responses to pressing social challenges such as, publicl housing issues, unemployment and low living standards. 

Instead of enlarging the sewer system, green solutions at street level have been implemented in St. Kjelds to efficiently lead stormwater to the harbour where it can be evacuated without causing any damage to the city landscape. Specific goals include:

• Prevent flooding in the neighbourhood of St. Kjelds by managing the stormwater/rainwater in a sustainable manner, through blue solutions on the surface;
• Create more green spaces and enhance biodiversity;
• Develop a stronger neighbourhood identity by bringing tangible solutions to the citizens;
• Present a scalable climate change strategy that can inspire other cities.

The project commenced in 2012 with the establishment of “green” (vegetation) and “blue” (water) solutions both in private courtyards and in urban spaces with a focus on St. Kjeld’s, Tåsinge and Bryggervangen squares. In accordance  with the strategy, 20% of the covered surface area in the neighbourhood would be turned into green areas and 30% of rainwater would be directed away from the sewer system. The concept introduced blue cloudburst solutions in the upper and middle part of the catchment area. The rainwater is channeled into a cloudburst sewer located in the lower part of the catchment area which directs rainwater to the harbour. Other solutions such as green courtyards, green roofs (for example on smaller backyard buildings), water tanks and rain gardens also absorb water and assist in reducing pressure on the sewer system. In case of heavy rains, cellars are secured by raised stairways forcing excess water to run from the courtyard to the road. Moreover, the different “green” surface solutions (Sustainable Urban Drainage Systems - SUDS) provide recreational value for the city and its residents and contribute to enhancing the quality of life in the neighbourhood.

The project involves partnerships with both local and national agencies and businesses. Citizens living in the neighbourhood were involved in the implementation of the strategy and a board with local residents as members was appointed for the square at Tåsinge Plads. The City of Copenhagen has established partnerships with local green NGOs (e.g. Miljøpunkt Østerbro), local political secretaries (Lokaludvalg), and local entrepreneurs (e.g. Østergro Rooftop farm). The City of Copenhagen has negotiated a partnership with Copenhagen’s Utility service, HOFOR, who provides financial support for aspects of the climate adaptation projects.

The integrated urban renewal project in St. Kjelds was allocated a total budget of 60 million dkk. (US$ 8.7 million), from the former Ministry of Housing and the City of Copenhagen.

Other resources include:

• The local project secretariat consisting of 5-6 people (planners, architects, communication specialists, political scientists etc.);
• HOFOR (Copenhagen’s utility service company);
• The Climate Department (City of Copenhagen);
• Different local organizations and NGOs, boards etc.
• The local steering committee, consisting of residents and representatives from 7 different city administrations.

Commencing in 2012, a "city life" survey has been conducted annually in St. Kjelds. The purpose of the survey is to assess and evaluate how the residents are  using public spaces in the neighbourhood. Once the results are analyzed, the city can determine which urban areas are functional and which are dysfunctional and then develop strategies to improve the physical spaces.

Bryggervangen's square is a good example of how the strategy has changed the urban structure at some key places in St Kjelds. This area is an intersection that was previously entirely covered with asphalt, causing orientation related problems among pedestrians, cyclists and motorists. The aim of the redevelopment was to create a green urban space and to regulate traffic more effectively. As part of the urban transformation plan, white stripes were painted on the roadway and parking lots moved to the shady side of the street to facilitate access to green space for residents. A newly created green stream will effectively channel rainwater to the harbour during a cloudburst to avoid damage in the neighbourhood.

Primary results of the Climate-Resilient Neighbourhood strategy include:

• Copenhagen's citizens are more aware of climate change and the need to adapt the city to cope with heavy rains and cloudbursts.
• Residents gain inspiration through different initiatives developed by the integrated urban renewal project and are motivated to start their own projects which contribute to the local community.
• St. Kjleds has developed an identity as the Copenhagen Climate Resilient Neighbourhood and has improved its reputation as a place to live and work.

Staff from the City of Copenhagen together with representative from the Danish companies behind the St. Kjelds project have visited New York City. The purpose of the visit was to demonstrate how climate adaptation measures will make New York more resilient to climate change and extreme weather, whilst at the same time improving life quality for the citizens. A three year partnership between the cities has been embarked upon.

New and combined solutions for climate adaptation represents a challenge to the legal system, organizational and economic arrangements, and the physical structure of the city. These issues can be overcome through communication and interdisciplinary work between the stakeholders.

Through the Climate-Resilient Neighbourhood strategy, the City of Copenhagen is, for the first time, empowering an entire neighbourhood to combat the effects of climate change. A network of institutions, political organizations, associations and individuals are organized formally and informally to protect the environmental interests of St. Kjelds. As an urban renewal program, the Climate Resilient Neighbourhood plan helps stakeholders to set a common agenda for the development of their neighbourhood. The residents have been effectively contributing to different projects with local knowledge, ideas and resources at the Tåsinge Plads, Bryggervangen and St. Kjelds Plads squares. Their ideas have been included in the final plans developed by the architects for the projects. This participatory method is being applied to the City of Copenhagen’s strategy for climate adaptation developed by the Technical and Environmental Administration.

Climate Resilient Neighborhood, Urban Innovation Database, http://www.urban-innovations.org/index.php/Climate_Resilient_Neighborhood (accessed 21st March 2017).

Climate Resilient Neighborhood, Guangzhou Award for Urban Innovation, http://www.guangzhouaward.org/en/2016-12/29/c_66334.htm (accessed 21st March 2017).