More than 11,000 homes in England to be built on land at high risk of flooding

Exclusive Guardian and Greenpeace analysis finds areas hit by recent storms are planning houses on floodplains

More than 11,000 new homes are planned to be built on land at the highest risk of flooding in the regions battered by the worst winter storms in a generation, the Guardian has learned.

An analysis of planning documents reveals that 11,410 new homes have been planned for land the government considers high-risk in the seven English counties where thousands of properties have been devastated by flooding since November.

In Shropshire, where a major incident was declared and residents were evacuated during Storm Dennis, 764 homes are set to be built in areas with a high flood risk. In Doncaster, where the Fishlake area was flooded in November, nearly 4,000 homes are intended for such flood zones.

The government is facing renewed calls to review its housing strategy as experts, local authorities and insurers warn that building on floodplains is increasing the danger to thousands of people from extreme storms such as Ciara and Dennis, which climate scientists say will become more commonplace.

The government aims to build 300,000 homes a year by the mid-2020s to help ease a chronic housing shortage across the UK. Yet local authorities say they are struggling to meet these demands because of a dearth of available land, leading to as many as one in 10 new homes being built on high-risk flood sites since 2013.

Dr Doug Parr, the chief scientist at Greenpeace UK, said the government’s housing policy was “literally planning for disaster”. He added: “Why are we planning to build more homes in high-risk flood areas when we know that the situation is only going to get worse because of the climate emergency?”

A joint investigation by the Guardian and Greenpeace’s Unearthed news unit found that of the 11,410 new homes planned across seven flood-stricken English authorities, 1,479 are in four of the areas hit hardest by Storms Ciara and Dennis: Calderdale, Herefordshire, Shropshire and Worcester.

In three regions hit by severe flooding before Christmas – Doncaster, Sheffield and Central Lincolnshire – a further 9,931 new homes are to be built on high-risk flood land. The government defines high-risk areas as having a 1% or greater chance of flooding in any year.

The data was unearthed by cross-referencing local planning documents and street-level addresses with the government’s national map of flood zones.

Building on land prone to flooding is a risk to new homeowners and compounds the danger for surrounding areas, experts have said, as floodwater that could otherwise be soaked up by green space instead runs quickly off concrete and into rivers.

In Herefordshire, which experienced unprecedented flooding last week as the River Wye rose to the highest level since 1795, 325 homes are earmarked for high-risk flood zones over the next few years. Some of this land has already been left underwater by Storm Dennis, according to the Herefordshire council leader, David Hitchiner.

John Harrington, the council’s cabinet member for infrastructure and transport, described the government’s housing policy as “completely and utterly flawed” and that it was forcing local authorities to approve “idiotic” developments on floodplains so they can meet demands from Whitehall.

“Central government just say: ‘There’s a housing target, now go do it.’ It’s really quite stupid. It’s devolving responsibility without giving the authority any power or money to deal with the situation. It is absolutely unacceptable,” he said.

Concerns have also been raised that homeowners who buy new properties on at-risk land are in “potential insurance blackspots” as they are not eligible for cover under the government’s Flood Re insurance scheme, potentially leaving them liable for crippling costs in the event of damage.

The Association of British Insurers said building on unprotected floodplains was “simply storing up problems for the future” and that stricter checks and sanctions should be introduced to stop developers from finding ways round planning regulations.

A spokesman for the Ministry of Housing, Communities and Local Government said: “Local authorities have a responsibility to assess the number of homes their communities need, and our planning policy is clear that housing should be located in the areas at least risk of flooding. Where development in a risk area is absolutely necessary, sufficient measures should be taken to make sure homes are safe, resilient and protected from flooding.”

Scott Cardwell, Doncaster council’s assistant director for economy and development, said the council was only identifying areas in flood zones for housing where they already have planning permission and are “deliverable, viable, and safe”. He added: “They have all complied with national planning policy and the sequential and exceptions tests and have had site-specific flood risk assessments and mitigation agreed in conjunction with the Environment Agency and lead local flood authority.”

In the valley of Calderdale in West Yorkshire, which has been hit by three major floods in eight years, the council’s leader, Tim Swift, said it had removed some sites at high risk of flooding from its local plan after a risk assessment. However, he said that where houses were still proposed for flood-risk sites they would not be developed “until measures have been put in place to ensure that they are safe”.

Some council leaders have raised doubts about the efficacy of the measures used by developers to mitigate the flood risk of new homes, such as “sustainable urban drainage systems”. Some have said that paving over absorbent land simply exacerbates the problems downstream.

Parr called for government to rethink its housing policy and give more powers to environmental watchdogs “to keep developers in check”.

He added: “It’s high time both local and central government started treating the climate emergency as if it was real – because it is.

“One of the problems is that by cutting the budgets of both local authorities and the Environment Agency, the government has effectively tilted the playing field in favour of developers. We have a housing policy that tends to put housebuilders’ profits before people’s chances of not seeing their homes underwater.”