01 · The problem
What is happening
On 2 July 2011, an extreme cloudburst flooded large parts of Copenhagen, causing extensive damage to basements, roads and infrastructure. In response, the city adopted a Cloudburst Management Plan in 2012, which combines conventional sewer upgrades with surface solutions: streets designed to channel water, parks that can temporarily store it, and green areas that absorb rainfall. Projects such as the climate-adapted Enghaveparken and Tåsinge Plads have become internationally referenced examples.
Moderate severity. Material effects on people or ecosystems; actively managed. Severity is descriptive editorial metadata summarising documented effects. It is not a measured index or a score.
02 · Causes
Why it is happening
- 01
Intense short-duration rainfall
Cloudbursts deliver large volumes of rain in a short time.
- 02
Sealed urban surfaces
Paved surfaces send water rapidly to sewers.
- 03
Sewer capacity limits
Pipes designed for past conditions cannot carry extreme volumes.
03 · Impacts
Who and what it affects
- 01
Property damage
Flooding damages basements, buildings and infrastructure.
- 02
Health risks
Combined sewer overflow can expose people to contaminated water.
04 · Solutions
Documented approaches
Cloudburst Management Plan
Citywide plan combining surface and underground water management.
Expected effectDesigned to reduce damage from extreme rainfall events.
Multifunctional public spaces
Parks and squares that store water during storms.
Expected effectAdds green space while managing floods.
Stormwater tunnels
Large pipes that carry cloudburst water to the harbour.
Expected effectIncreases drainage capacity.
05 · Key indicators
What can be measured
- Trigger event
- Cloudburst of 2 July 20112011
Extreme rainfall that led to the city's Cloudburst Management Plan (2012).
06 · Sources
Where this comes from
- [1]City of CopenhagenKøbenhavns Kommuneinternational.kk.dk(opens in a new tab)
- [2]Climate-ADAPTEuropean Environment Agency and European Commissionclimate-adapt.eea.europa.eu(opens in a new tab)
Links open the publishing organisation's site. Some point to the publisher's main page, where the named report or dataset can be found.