Higher water bills for homes with paved driveways should be considered to tackle rising flood risk, the Government’s infrastructure advisers have said.
More than 600,000 English properties could be in areas at high risk of surface flooding by 2055, according to a report from the National Infrastructure Commission (NIC) on Tuesday. This includes 325,000 already at high risk from this kind of flooding, when heavy rain overwhelms the drainage system. A further 230,000 could be at high risk, with a 60 per cent change of being affected, by 2055.
But another 65,000 properties are being put at risk because of the rise in impermeable surfaces – mostly paved driveways – that stop rain water running off into the ground.
The NIC has called for the Government to review options to limit the use of paved driveways. Options include water companies levying charges based on the area of a property that is paved with a non-permeable surface.
Such charges have been used by water companies for some commercial properties. Regulator Ofwat has called for trials in residential areas.
Other options include changing planning rules, which currently mean homeowners do not need permission to pave over less than five square metres of their front gardens.
Homeowners could also be required to use permeable materials, such as block paving or gravel, or use green roofs for extensions.
The report from the NIC calls for £12 billion of infrastructure investment over 30 years, which it says could tackle the growing threat of surface water flooding, when heavy rain overwhelms the sewage system, from climate change and population growth.
The investment could move 250,000 properties out of the high-risk flooding category, it estimates.
Some of the money could be covered by the £56 billion water company investment already earmarked by the Government to reduce sewage spills.
Sir James Bevan, the chief executive of the Environment Agency will on Tuesday call for increased private investment to help adapt the UK’s infrastructure, which he will say has been overlooked in the drive to cut emissions.
“Today, flooding causes £670 million worth of damage every year to non-residential properties across the UK,” he will say.
“Unless we take further action to adapt, under a very plausible 2C by 2100 warming scenario, those damages will be 27 per cent higher by 2050 and 40 per cent higher by 2080.
“This is not what the next generation needs on top of the rising cost of living.
“Only the private sector has the scale of the resources we need to tackle a challenge of this magnitude, and because private sector companies increasingly recognise that mitigating their own impacts on the climate and adapting their business for a climate changed world is not just the right thing to do but good business.
“Companies that do so will thrive, and those who don’t will not survive.”
Threefold rise in paved front gardens
Paved front gardens rose threefold in a decade from 2005, according to a 2015 study by the Royal Horticultural Society in 2015.
In London, where 1,500 properties were flooded during storms last year, half of all front gardens are paved over.
Other recommendations from the NIC include a ban on new homes automatically connecting to the local drainage system. Developers could instead be required to include sustainable alternatives such as swales or ponds.
“It’s clear that faced with more intense rainfall and increased urbanisation, we need to start taking this type of flooding far more seriously,” said Professor Jim Hall, a national infrastructure commissioner.
“The solution is clear – reducing the amount of water flowing into drains, whilst also improving the capacity of those drains.”
That means stopping urban creep from increasing the amount of storm water that drainage systems have to cope with and giving nature more opportunities to hold on to excess water, as well as targeted investment to ensure sewers can cope with growing pressures.
“While sustained investment is needed, the estimated additional costs are relatively modest. At least as important is a more joined-up approach to owning and acting on the problem.”