Around 17,000 homes have been built each year in areas of high or low flood risk in England and Wales over the past decade, says a paper published yesterday in the journal Environmental Research Letters. There has also been a rising trend in the proportion of new homes potentially at risk against those that are safe. Only a handful of authorities have seen a decline, according to Viktor Rözer and Swenja Surminski from the Grantham Research Institute.
Their distribution is also highly uneven, almost all of them being found in only 34 districts, or 10% of all local authorities where new homes have been built. London, the Thames Valley and other urban areas along estuaries, such as Liverpool, Hull and Bristol are cited in particular.
Climate change is expected to worsen the situation, leaving even more homes at risk of inundation. This is particularly so for poorer areas.
“Our results indicate that already struggling neighbourhoods will face this issue more likely than other types of neighbourhoods This can lead to knock-on effects where a low or lacking ability to cope with increasing flood risks of individual households or properties can decrease both the attractiveness and property value of a larger area as chances for a full recovery after a flood event decrease and community development is impaired. This could bear a wider risk with systemic implications such as an increase in mortgage defaults and foreclosures due to a combination of decreasing real estate prices and lower chances of financial recovery,” says the paper.
Although future investments in flood defences could reduce the impact, “it is uncertain where and to what degree this can and will be done”, it adds.
The study found that around 5% of the 1.3m homes built between 2008 and 2018 are at high risk of flooding, generally from rivers or surface water, with another 10% at low risk. Assuming warming of 2°C by the 2050s, the figures will rise to 7% and 14%, respectively. But for disadvantaged areas, it projects that 9% will become particularly prone to flooding, with 21% at lower risk.
“My motivation to do this work focuses on how climate change is not only about reducing carbon emissions but also about adapting to the impact of it. There’s a lot of missed opportunities with homes. Once they are built they will be there for decades or often hundreds of years. That’s something worth looking at. How do the neighbourhoods look when they are built and how will they be affected by climate change?” said Rözer.
“The biggest challenge that the UK is facing is flooding, so this research is trying to understand what are the social but also the economic implications of flooding. Where we build and how we build is a key issue,” Surminski added.