Urban creep increases the risk of flooding

Far too many people have experienced local flooding in recent months caused by extreme weather. One problem is surface water – with so many hard surfaces in urban areas, it doesn’t have anywhere to go and the result is localised flooding. The cause in part is the loss of green land in built up areas – as vegetated areas are built on or paved over, the typical urban street struggles to cope in periods of heavy rainfall.   

A new report has found that Edinburgh is losing the equivalent of 15 football pitches of green land every year, more than half of which is due to urban creep – that’s the loss of permeable surfaces such as flower beds and lawns.  

The team of researchers from NERC Centre for Ecology looked at changes in the urban landscape of Edinburgh over the last 25 years. Commissioned by the Centre of Expertise for Water, the study looked at two aspects of urbanisation; urban creep and urban expansion. With the help of aerial photos from 1990, 2005 and 2015, researchers were able to estimate the amount of green land that had been lost. It was an average of 11.3 hectares every year. Most people would assume that was due to urbanisation, but surprisingly more than half was due to urban creep. Unlike planned urbanisation which is subject to planning to reduce the flood risks, these small scale changes can have a significant effect on local flood risk.  Concreting over a front garden for more parking, for example, can mean more water runs off into road and neighbouring properties. If a row of houses concrete over their front gardens the problem is even greater as seen in the photo above after an intense period of rain (Gravesend in 2019). I have experienced this problem first-hand, as have many home owners, so I can’t stress enough the need for permeable surfaces in the garden to help the water sink into the ground rather than run off and overpower local drains and streams and cause localised flooding.

I doubt Edinburgh is alone in losing green land, I bet it’s happening in every community as lawns and borders, trees and shrubs, are replaced in the desire to have low maintenance gardens with conservatories, patios, driveways, garden offices, and even artificial lawns.


Centre for Ecology and Hydrology

CREW Scotland’s Centre of Expertise for Waters is a partnership between the James Hutton Institute and all Scottish Higher Education Institutes and Research Institutes. The Centre is funded by the Scottish Government.

Feature photo Shutterstock

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