Sponge cities in war against floods

The recent floods in Europe and the rest of the world have emphasized how important it is to prepare for extreme amounts of water across cities. To prevent such significant damage, cities have started to incorporate water drainage solutions in city planning.  

17 Sep. 2023

By Liv Watts and Johanne Hanghøj Jørgensen

In Copenhagen, Denmark, the council has been preparing for cloudbursts and rising water since 2012. This was in response to a severe cloudburst in 2011, which caused chaos throughout the entire city, and is estimated to have accumulated between £600 million and £700 million in damages.  With the current climate crisis, the likelihood of a similar or worse situation emerging is vast. Therefore, an estimated £1.5 billion and 357 urban projects have been put in place to make Copenhagen a ‘Sponge city’. Most of these projects are urban areas with exposed lakes and grass that have the ability to absorb excess water as well as roads that can lead the water to contained areas. These areas are made to be multipurpose, enabling the public to enjoy green urban areas and water draining when needed.   

Six of the 350 cloudburst projekts around Copenhagen. Illustration: Olivia Watts

Other major cities over the world that are exposed to flash flooding have started to take inspiration from Copenhagen’s methods when preparing for future cloudbursts, with London being one of them. As Luke Strickland, employee of Ramboll UK to construction news “The solutions Copenhagen found could be applied to many of our cities, converting urban streets into Cloudburst or green streets instead.” As part of an ambitious plan from Thames Waters, part of The Drain London Partnership is set to invest almost £32 billion in their Drainage and Wastewater management plan 2025-2050 in London and Thames Valley. In the plan, Copenhagen is mentioned as being a leading city for SuDs. 

The Drain London Partnership
Consist of Thames Water, Environment Agency, and London Councils.
The aim to: improve knowledge of the surface water and drainage system
They want identify areas most at risk of flooding and find ways to reduce flood risk.
Source: London.gov.uk

Video of cloudburst magement in Copenhagen – By Olive Watts and Johanne Jørgensen