Cloudburst Management Plan, Copenhagan

Copenhagen. Credit Ramboll
Area characterisation: 

The “Cloudburst Management Plan” addresses 8 central city catchments (Norrebro, Ladegards-aen and Vesterbro, Valby & Vanlose), encompassing a total area of 34 km². It includes 300 separate projects that are expected to run over the course of the next 20 years.

The Ladegads-Aen catchment was selected as a prototypical test area due to its high risk to flooding and sea surges. Comprehensive site analysis led to establishing the Copenhagen Cloudburst Formula and a Cloudburst Toolkit of urban mitigation strategies and components

Slideshow:

Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen ASLA Copenhagen ASLA Copenhagen ASLA Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl Copenhagen Cloudburst Masterplan. Credit: Ramboll Studio Dreiseitl
Objective: 

In July 2011, in less than two hours, Copenhagen was hit by an extreme 1000-year storm event – or Cloudburst – where 150mm of rain left large areas of the city under up to one meter of water. The 2011 event had been preceded by a 100-year storm in August 2010 and was hit again in 2014. Copenhagen realized that Cloudbursts were not a one-off occurrence; the threat compounds as harbor sea levels are predicted to rise one meter by 2110. In a city where many buildings and services are located below street level and where stormwater and sewage are in a combined pipe system, contaminated floodwater penetrated buildings and city infrastructure.

Traditional drainage solutions such as underground reservoirs are becoming less viable as utilities occupy more underground space. Extreme weather events cannot be managed by conventional pipe systems and their occurrence becomes more difficult to predict

Conventional infrastructure is considered to be generally technical, underground, hidden elements while Blue-Green solutions are low-tech, on the surface, and interactive. The Blue-Green Approach develops a synergistic relationship between the two, integrating climate adaptation solutions within the limited confines of urban space, encouraging a solution utilizing the best of both techniques.

The Copenhagen Concretization Plans were commissioned to combat climate change following 2011’s flood. These integrated, multi-disciplinary plans bridge the gap between planning and site-specific solutions through the application of a typology-based Cloudburst Toolkit.

The “Cloudburst Management Plan” addresses 8 central city catchments (Norrebro, Ladegards-aen and Vesterbro, Valby & Vanlose), encompassing a total area of 34 km². It includes 300 separate projects that are expected to run over the course of the next 20 years.

Actions: 

The process was formalized as the Copenhagen Cloudburst Formula, a six-step procedure for integrating the Blue-Green Approach:

  1. Data and Investigation: The city investigated, identified, and ranked areas according to their overall threat due to Cloudburst risk indicators, their
  2. ...
Transferability of the result: 

The Copenhagen Formula adapts interdisciplinary approaches, moving away from isolated thinking. A common vision aligned engineers, hydraulic experts, GIS and information technologists, architects, planners, biologists, economists, communication specialists, and landscape architects with local citizens, investors and politicians.

Cloudburst solutions are now implemented in local plans where synergy projects are encouraged between municipalities, water utilities, and philanthropists as catalysts for development. Public participation workshops encourage and allow citizens to actively shape their municipality's Cloudburst strategy.

Blue-Green is the future for establishing urban ecological waterscapes while balancing sound investment and economic opportunities with social benefit improvements.

Blue-Green Infrastructure represents the next generation of water infrastructure considerations where nature, city and recreational space are rolled into a holistic package. Cities around the world can look to the Copenhagen Cloudburst Formula as a model for implementing innovative, pragmatic, feasible measures within existing urban fabric.

Lessons learned: 

The insurance damage savings and the increase in real estate value are two of the highest socio-economic benefits from Cloudburst adaptation.  Blue- Green is the future for establishing urban ecological waterscapes while balancing sound investment and economic opportunities with social benefit improvements.

Cloudburst solutions can provide much more than just stormwater management. The strategic flood masterplan is the opportunity to safeguard Copenhagen while providing the foundations for a high-quality city environment. Resilient urban ecological waterscapes are the foundation for vibrant public realm spaces that are culturally and socially significant and contribute to the economic longevity, quality of life, and well-being of cities. 

PUBLIC-PRIVATE ENGAGEMENT – LASTING BENEFITS:
The Copenhagen Formula provides a structure for integrating built, existing context with retrofit Blue-Green solutions.
The implementable, pragmatic tools mitigate extreme storm events and improve our cityscapes. Private developers and homeowners alike become champions for local solutions where a multi-disciplinary, cross-agency collaboration engaged designers, planners, sociologists, economists, biologists, geographers, information specialists, and communication experts interacting with public utility companies, stakeholders, interest groups, local politicians, and investors.
Cloudburst solutions are often left out of upstream area planning where residents see no flooding problems. Yet water has no boundary. Municipal borders must be lowered to develop a common vision across disparate districts. A recent interactive workshop led by the Engineer and Landscape Architect in a suburb of Copenhagen engaged residents through a series of interactive sessions designed to raise awareness and survey desired citizen interests. Hydraulic function was presented in an engaging, educational sequence that involved the public interest with private development goals.

Goals:

  • Enhancing sustainable urbanization
  • Developing climate change adaptation

NBS Actions:

  • Nature-based solutions and the insurance value of ecosystems

Keywords:

Green infrastructure, Green space management, Heritage (cultural and natural), Human well-being, Northern, Resilience, Societal choice, Temperate, Think Nature, ThinkNature, Urban, Urban Regeneration, Flood peak reduction, Improve connectivity and functionality of green and blue infrastructures, Increase infiltration / Water storage, Increase Biodiversity, Increase quality and quantity of green and blue infrastructures, Increase awareness of NBS solution & their effectiveness and co benefits, Reduce load to sewer system, Increase population & infrastructures protected by NBS, Reduce run-off

Client:

City of Copenhagen, City of Fredriksberg, HOFOR

Design team:

Ramboll and Ramboll Studio Dreiseitl

Awards:

C40 Cities Award 2016 category: Adaptation in Action

2016 American Society of Landscape Architects Award of Excellence

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