Towns may have to be abandoned due to floods with millions more homes in Great Britain at risk

Every constituency projected to be at greater risk, with many areas likely to be uninsurable, Guardian investigation finds

Millions more homes in England, Scotland and Wales face devastating floods, and some towns may have to be abandoned as climate breakdown makes many areas uninsurable, a Guardian investigation has found.

New analysis from the insurance industry, seen by the Guardian, reveals the extent of concern in the sector, with bosses warning that large swathes of housing and commercial property in densely populated areas will be at greater risk.

Separately, experts have said that some towns may need to be abandoned as homes and businesses struggle to get insurance in areas repeatedly battered by storms and rising sea levels.

Densely populated areas including London, Manchester and parts of north-east England, are likely to be worst hit. Experts also say London’s flood defences need to be updated urgently to protect the capital from devastating floods.

“The findings are stark,” said Jason Storah, chief executive for UK & Ireland general insurance at Aviva, which published the analysis. “Millions more properties will be at risk from flooding, with rising temperatures, increased urbanisation and inadequate drainage.”

Tenbury Wells, a market town in Worcestershire, has become the first in the country to find that its public buildings are uninsurable. The town has historically suffered damaging floods about once a decade, but in the past six years people there have been hit four times.

“We do feel abandoned,” said Lesley Davies, the deputy mayor of Tenbury council. “We are the blueprint for what could happen in the future – there may be other towns getting towards that situation, there are a lot of vulnerable towns on rivers all over.”

Aviva’s report highlights growing concern within the insurance industry about the impact of severe weather events that are being driven by the climate crisis.

Storah said: “We are not talking about this because we are waving a flag about climate or sustainability – it’s nothing to do with that, our business is totally correlated with what happens in the environment … we are in this and we cannot avoid it.”

Aviva analysed every parliamentary constituency in England, Scotland and Wales to assess how vulnerable they were to flooding. In England, it found the number of properties at risk from flooding was expected to increase by more than a quarter (27%), from 6.3 million to 8 million, with the number of properties in high-risk areas for flash flooding – which are harder to predict and protect against – likely to increase by up to 66% by mid-century.

It also found:

• Every constituency in Great Britain is projected to have increased flood risk in future. In England, 69% of constituencies are likely to have an increase of more than 25% in the number of properties facing flood risk by mid-century. In Wales and Scotland, every area is projected to have a similar rise with many being much worse hit.

• Bermondsey and Old Southwark in London and Boston and Skegness in Lincolnshire are projected to have about 90% of homes at risk from river and coastal flooding by 2050 – the highest proportions in the country.

• Overall London and Yorkshire and the Humber collectively represent more than half of the top 20 constituencies affected by river and coastal flooding, highlighting that the east of England could be most negatively affected.

• Surface-water flood risk is likely to be particularly acute in dense urban areas, with 14 London constituencies ranked in the top 20

• Bournemouth East shows the largest projected increase in surface-water flood risk, with its low-lying topography and inadequate drainage making it particularly susceptible.

• Over the past decade, 110,000 new homes were built in the highest risk flood zones, equivalent to one in 13 of the new homes built. Aviva calculates that if this trend were to continue, 115,000 of the government’s planned 1.5m new homes would also be in the highest-risk flood zones.

Speaking to the Guardian, Emma Boyd, the former chair of the Environment Agency, said it may be too expensive to build the flood protections needed to save some areas.

She said some may have to be abandoned as it becomes too costly to protect houses and businesses. “I think particularly when money is constrained, resources are constrained, some of those very difficult decisions are going to have to be made by government to make sure that the money that is available for flood prevention is having the most impact given fiscal constraints, but that is a very difficult political decision for our leaders to make,” she said.

Boyd warned London was also at high risk and that the government should be working urgently to improve current defences.

“A lot of people think that they are protected because of the Thames Barrier and the range of different mechanisms along the embankments that protect London from sea level rise and river flooding, [but] a great project needs to happen in terms of funding, raising the embankment along the River Thames and building a new barrier.”

Cover photo:  Flood waters surrounding houses in Wraysbury, Berkshire in January 2024. Greater London and Yorkshire and the Humber are two regions at particular risk in the coming years. Photograph: Daniel Leal/AFP/Getty Images