Research by property search firm SearchFlow  shows underinvestment in defences and climate change means the annual cost of flooding in England and Wales has reached £1bn.
The cost of individual major flooding events is also rising. According to the Environment Agency, a major coastal flooding event in the Humber estuary could cause damage worth £266m. As sea levels rise, this could rise to £1.4bn by 2040.
The Environment Agency predicts that in the next 30 years sea levels will rise by approximately 40cm. Without improvement in flood defences, this would increase the number of properties at significant risk of flooding in Eastern England by 48%. By 2040 the cost of a major coastal flooding event could reach £16bn.
Such high potential losses would place heavy strain on the insurance market – the Association of British Insurers calculates an increase in the cost of a single flooding event to £12bn would require 10% of the capacity of the global reinsurance market.
Richard Hinton, business development director of SearchFlow said: “The twin impacts of climate change and ongoing property development mean the danger of flood liability is growing rapidly. So great is the potential risk from rising sea levels and construction on the floodplain to accommodate a rising population that the UK’s flood liability could come to dominate the global reinsurance market.
“In practice, that would mean many in high-risk areas would be unable to obtain insurance at all, which would significantly reduce the value of their properties and potentially could put homeowners in breach of their mortgage agreements.
“Many property owners don’t realise the extent of the danger they face. It’s no longer safe to assume that historically low flood risk is an indicator of what to expect in the future.
“Particularly in coastal areas and parts of the UK which face significant risks of flood damage, it’s essential those purchasing property are fully aware not just of the risks they face today, but of those that will develop in the coming years.”
Currently the UK spends £570m per year on flood defences to protect the one in six properties that suffer flood risk. At the present level of spending, SearchFlow’s research indicates the annual cost of flooding could rise to £13.5bn per year. To mitigate the growing risk from flooding, the Environment Agency calculates spending on flood defence must be increased by £20m each year to at least £1.04bn annually by 2035.
According to the Association of British Insurers, the present level of spending on flood defences is insufficient to prevent 43% of flood defences being in a ‘moderate, poor or very poor’ condition. The Environment Agency calculates that spending on flood defence represents good value for money, as every £1 spent on flood defence reduces the damage from flooding and coastal erosion by £8.
Richard Hinton continues: “With King Canute unavailable to push back the water, the UK is reliant on flood defences to protect the properties at risk of flooding. Although hundreds of millions per year sounds like big spending, it’s a drop in the ocean compared to the cost of the damage the UK faces from flooding.
“Every year the government fails to increase spending on protection from flooding condemns property owners to potentially catastrophic losses down the line. In the meantime, all property owners can do is ensure they have a full understanding of the risks they face.”
Regional flood risk
SearchFlow’s research shows among regions with more than 10,000 properties at ‘significant’ risk of flooding, residents of the borough of Windsor and Maidenhead are currently the least well-informed property owners about flooding relative to the risk they face.
Across the UK, the proportion of buyers conducting flood searches varies from 2% to 22%. But in the SL postcode – one of the UK’s three most at risk local authorities – only 6% of transactions involve a flood search.
The local authorities with the highest number of properties at significant risk of flooding[i]  are Bristol and the boroughs of East Lindsey and the Windsor and Maidenhead. Kingston-upon-Hull and the east Riding of Yorkshire also contain high concentrations of properties at significant risk of flood.
Richard Hinton comments: “There are stark variations between different local authorities in terms of the seriousness with which conveyancers treat flood risk – and worryingly they don’t necessarily correspond to the level of risk the different areas face.
“Despite encompassing one of England’s three most at-risk areas, the SL postcode barely sees half the average number of flood searches across England. Homebuyers need to make sure their conveyancer checks thoroughly that they know the level of risk they face from flood so they can make their purchase with their eyes open.”