Cardiff faces the highest flood risk in Britain, dramatic new data reveals

Cardiff is set to be one of the cities most affected by extreme flooding caused by climate change. Credit: PA

Cardiff faces the highest flood risk in Britain, according to new data from a national flood risk model.

By 2050, up to 15.1%, or 33,000, of Cardiff properties will be at risk of flooding.

The model, designed by flood modelling company Fathom, is the first to use climate change data rather than just historic data to predict the areas most at risk.

The model simulates the impact of future climate change when predicting flood hazards for the years 2030, 2050 and 2070.

The new data shows that the UK must "improve forward planning for extreme weather events," according to Professor Paul Bates CBE, Chair of Hydrology at the University of Bristol and co-founder of Fathom.

He also warns that the "people most likely to be affected are the least likely to have the resources to cope with a flood."

Watch: ITV Wales reports on flooding in Cardiff after Storm Jorge in 2020.

  • Which properties are at risk?

The modelling comes as 1.09 million properties across Britain have already been deemed "at risk" of inland or rainfall-driven flooding.

The data suggests that this could rise to 1.35 million by 2050, which would be putting 250,000 extra properties at risk.

In Cardiff alone, 33,000 properties are predicted to be at risk by 2050 due to the impact of climate change.

1.35 million properties across the UK could be at risk of flooding by 2050. Credit: Dr Oliver Wing, Chief Research Officer, Fathom

  • How has Cardiff been hit by flooding before?

In 2020, extreme weather like Storm Dennis and Storm Jorge caused severe flooding across Wales, and Cardiff was hit particularly hard.

South Wales Police declared 'critical incidents' as parts of Bute Park, Ely, Llandaff and Whitchurch were left submerged and many were evacuated from their homes.

The floodwater also left many businesses, vehicles and train lines under water and unable to operate.But perhaps the most famous incident of extreme flooding in Cardiff was in 1979. The River Taff burst its banks and caused widespread damage to the city – particularly in areas like Canton, Pontcanna, Grangetown and Riverside.

Thousands of homes were under water and many residents had to be evacuated, just days after Christmas.

Watch: Archive footage of Cardiff's 1979 floods shows a circus in Sophia Gardens evacuating its animals to a safety.

  • How is the flood risk being tackled?

After Wales' extreme flooding in 2020, the First Minister pledged up to £10 million in emergency funding for flood victims.

Since then, the Welsh Government has announced a spend of more than £200 million to tackle flooding and problems caused by coastal erosion over the next three years. 

This funding will boost the budget of Natural Resources Wales, which looks after flood defences and local authority funding.

Professor Paul Bates CBE says that going forward, the risks of building on flood plains should be made clearer."In order to prevent placing already vulnerable people in harm’s way, we need to see greater action from government bodies around mitigation and adaptation,” he urges.

A mural near Cardiff city centre depicts what Cardiff could look like in the future if sea levels continue to rise. Credit: ITV Wales
  • How does climate change impact extreme weather?

These newest findings have taken into account climate change data to predict future flooding hazards for the first time.

And, extreme weather is on the rise across the UK, according to Professor Paul Bates CBE.

"In a warming world, the UK can expect to see more extreme flood events like coastal and flash flooding,” he says.

Back in 2019, Wales was the first country in the world to declare a 'climate emergency.'

Then, in 2021, The Welsh Government set out a 'net zero' target for 2050 as part of its commitment to tackling climate change. This means it will work towards balancing greenhouse gas emissions with the amount of gases it is removing from the atmosphere.

But many, like Cardiff climate activist Yasmin Belhadj, have been calling on politicians to do more.

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