Why tens of thousands of homes are built in high flood risk areas every year

Around 24,000 homes were built in high flood risk areas in England in 2016/17. In the aftermath of more severe floods, the figure may seem baffling, but the vast majority have the regulator's backing.

Flooding: around 24,000 homes were built in high flood risk areas in England in 2016/17 (Pic: Getty)
Flooding: around 24,000 homes were built in high flood risk areas in England in 2016/17 (Pic: Getty)

With communities across South Yorkshire, Lincolnshire and the Midlands struggling over the last month with severe flooding problems, the spotlight has been put on the effectiveness of the Environment Agency, the government-sponsored agency and statutory consultee with oversight of flood risks, and other local bodies in managing development in areas at flood risk.

"With the pressure to get homes built, councils are approving schemes which push the rules to their limits because of their possible environmental impacts," says Gavin Parker, professor of planning at Henley Business School, Reading University. "In the past, those sites would probably not have been developed".

Government figures show that, in 2016/2017, around 24,000 homes in England were built in areas designated by the Environment Agency as being at the highest risk of flooding. The agency produces maps which zone locations in terms of the flood risk from major rivers. It defines high-risk flood zones as areas that have a one in 30 chance of flooding in any given year (these are described as being in zone three). Medium-risk zones (zone two) are areas with between a one in 30 and a one in 100 chance of flooding in any given year, and low risk zones (zone one) have a lower risk than that.

If the site is in a flood zone 2 or 3, a sequential test is required for any major planning application over ten homes. This requires the applicant to compare the site subject to the application with other available sites to find out which has the lowest flood risk.

A large proportion of the 24,000 homes given permission in 2016/17 in areas of the highest flood risk are protected by flood defences, which is why, according to the CCC, the Environment Agency did not object to them.

Nonetheless, the CCC says that "this level of development still increases exposure in the event of defence breaches or overtopping." It estimates that "if the current trend continues until 2022/23, and the government meets its target to build 300,000 new homes in England per year into the mid-2020s, then there is the possibility of building between 105,000 and 165,000 more homes in Flood Zone 3 between 2018/19 and 2022/23."

The Environment Agency is consulted on planning applications which are in areas seen as being at medium or high risk of flooding. But it does not make the final decision on local planning approvals. And if it is concerned about a scheme on flood safety grounds, its objection will not necessarily lead to the scheme being rejected. That said, the agency reports that 99.4 per cent of planning applications involving new homes in England were decided in line with its advice on flood risk between 2017 and 2018.

However, the usefulness of the Environment Agency’s maps identifying areas of differing level of flood risk is questioned by Jessica Neumann, lecturer in geographical information systems at Reading University. She says that some of the recent flooding has not been in areas categorised by the agency as high risk. "The maps are based mainly on the risks of major rivers flooding," she says. "Flooding from heavy rainfall is far harder to predict and prepare for".

"It’s up to local authorities and their lead local flood authorities to develop strategies and planning policies to manage surface water," points out Hilary Ellis, sustainable drainage officer and flood risk contract manager at Cambridgeshire County Council. "This means introducing design guidelines so that as much water as possible is retained on site through sustainable urban drainage systems, green roofs and setting aside wetland areas".

Hugh Ellis, policy director at the campaign group the Town and Country Planning Association, says that a more strategic approach to managing water in urban areas is required with climate change taking effect. "Central government needs to give the Environment Agency a stronger remit, and effective regional partnerships are required to look at addressing flooding issues," he says.


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