Flooding in Urban Areas – The Green Infrastructure Solution

Written by Dusty Gedge Published in News

Increased flooding is likely to be one of the most serious effects of climate change in Europe. Cities will be particularly vulnerable to increased surface flooding – already over the last ten years, flash storms have affected many cities.


Average sealed surfaces in Cities in Europe

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Rising temperatures in Europe will also intensify the hydrological cycle, leading to more frequent and intense rain events. The stormwater systems in many cities across the continent will have to be upgraded – either through grey infrastructure or by integrating green infrastructure.

Flooding – intense rain affects Europe’s cities

Most cities lack the green space – and therefore the ability – to absorb rainfall. Sealed, impermeable surfaces channel water into stormwater drainage systems. During intense storms, the stormwater system can become overburdened, causing drains to back-up and flood.

Whilst river flooding is also an issue across Europe, surface water flooding can be reduced in cities by the use of urban green infrastructure interventions. Many cities still have combined sewers. When these become overburdened raw sewage can enter local rivers. These types of events often happen after long periods of drought. In London in 2004 and 2009 sudden, intense summer storms lead to significant pollution and fish deaths in the Thames.

On 2nd July 2011, a cloud burst inundated Copenhagen with 15cm of rain in less than three hours. Cellar streets and key roads were flooded. The flooding from the deluge is estimated to have caused almost €1Bn in damage to property. In 2014, in the same region across in Sweden, an intense summer storm over Malmö caused similar havoc. Many other cities have been affected over the last ten years by similar flood events, including London, Vienna and Montpelier to name but a few.

Green Infrastructure – a natural water management system in cities

Many cities across Europe are recognising the need to manage water differently. To manage water smartly, the use of green infrastructure is key. For over 30 years, many cities in German and Austria have made use of green roofs in new developments to help store rainwater temporarily. Increasingly, there is interest in other forms of Sustainable Urban Drainage Systems such as rain gardens and bio-retention ponds.

Retrofitted Rain Gardens South West London

Retrofitting green infrastructure into green spaces can be done. Turning amenity grassland into rain gardens can help climate proof cities. An recent example is a social housing estate in South West London. To add additional storm water storage, green roofs have been installed throughout the estate on smaller buildings.

EUGIC 2015 – promoting green infrastructure to reduce urban flooding

This example in London is just one of the many projects that will be celebrated at EUGIC 2015.  Innovative nature-based solutions can help cities become more resilient.  Managing water is one of the key themes of our event.

This is just one of the many reasons to attend EUGIC 2015.

Dusty Gedge