Why it's time to allow building in floodzones...

Why it’s time the government allowed new homes to be built in flood zones…

21 May 2019

Compared to the physical challenges already overcome in some parts of the world, living with the occasional brief flood event in the UK should be relatively simple. Just take the ever-present risk of major earthquakes in places like California and Japan. If Tokyo city planners had adopted the same approach as the UK government, there would have been no new buildings in that city since 1923!

Incredibly, there are already 5.3 million homes in UK flood zones, and if you believe the latest climate change predictions that number is set for a sharp increase. Large areas of the country currently categorised as low-to-medium flood risk will be re-evaluated, in line with greater frequency and severity of extreme weather events.

Flood zones are categorised from 1 to 3. 3a is high flood risk, and 3b is deemed a functional floodplain, ie a place for floodwaters running off higher ground to settle. Current planning policy prohibits all new development in 3b, and rightly so, given that conventional houses on conventional foundations would be certain not only to suffer flood damage, but also to aggravate flooding on neighbouring land.

Meanwhile, thanks to demographics and immigration, the UK has a requirement for 300,000 new homes every year. Since the turn of the century our population has grown by more than 10%, from 59m in 2000 to 66m in 2017. Eurostat predicts the UK population to be 77m in 2050 (when it will be the most populous country in Europe) and 85m in 2080.

The Thames Valley is a good example of a floodzone area where over two million people want and need to live. The corridor between London and Reading is prosperous and well-served by Heathrow, M4 and soon Crossrail. Unfortunately, this part of the country has a high flood risk, as we have seen in recent years. In 2015-16 when the Thames overtopped along many miles of its length, conventional homes were damaged, and property was destroyed. It’s only a matter of when, not if, this will happen again.

Current UK policy obliges housebuilders to create new developments on higher ground, sometimes far away from existing settlements which, apart from the negative impact on traffic and human convenience, actually increases flood runoff to lower ground.

Whereas the government recognises that suitable technology is available, the local planning authorities cannot usually sanction building in 3b flood zones because the National Planning Policy Framework (NPPF) deems new homes for those zones to be too ‘vulnerable’.

It is therefore paradoxical that the government thinks it is safe for 5.3m existing non-flood-proofed households to be in the flood zone but doesn’t think it is safe to accommodate people in new purpose-built flood proof homes.

In fact the government goes so far as to force the insurance industry to subsidise cover for those living in flood zone homes, so in effect encouraging existing flood zone home dwellers to remain.

The government strategy seems to be one of making existing homes ‘flood resilient’ (ie taking measures to mitigate flood damage) rather than ‘flood resistant’ (ie making homes impervious to flooding).

A cultural shift is called for, away from treating floodwater as an invading enemy to working with it according to its predicted depth, flow rate and floating debris. This theme could be summarised as ‘going with the flow’ rather than ‘reaching for the sandbags’. Bear in mind that the flooding we experience in the Thames Valley is hardly on a par with the Mississippi or Ganges deltas.

Much of this is about using simple technology to landscape a site, provide water channels and ponds, have raised roads, flexible utilities hook-ups and buoyant house foundations.

Such technology already in use in places like The Netherlands allows homes to be built in areas of even extreme flood risk. Houses are sited on specially-designed buoyant foundations, such that when flooding occurs, they simply float on the surface like any other vessel. When the flood waters recede, the homes gently settle back down on the ground. The method is demonstrably safe - certainly enough to convince Dutch mortgage and insurance providers - and it’s eminently practical. These homes are in fact flood-proof and, better still, the entire development in which they sit is designed to contain water.

What the Department of Communities and Local Government (DCLG) should do now is allow flood proof homes to be built in flood zones, provided that i) they do not make flooding worse elsewhere; ii) they provide safe access and egress; iii) they do not increase the burden on the emergency services; and iv) they are supported by a site specific flood risk assessment that demonstrates that the new development will not have a negative impact on flooding inside and outside the area of that development.

One of the reasons for the stasis is that there is a game of ping-pong between the Environment Agency and the DCLG. The former defers to the NPPF, which is the responsibility of the DCLG. But the EA is a statutory consultee on planning matters and is at pains to point out that it is not an urban planner.

Sadly there isn’t a Department of the (Natural and Built) Environment. If there was one it would encourage some joined-up thinking that is badly needed given the twin pressures of population growth and climate change.

The solution lies in the DCLG producing new guidance for NPPF allowing responsible housebuilders to get on with building safe and secure flood proof homes where people want and need to live.

For more information please contact

Guy Lane, Co-founder & Marketing Director,
guy.lane@kabina.co
tel 07798 832576
www.kabina.co

Kabina Ltd
13 Hawley Crescent
London
NW1 8NP
Kabina is a registered trademark.

Editor’s notes:
Neil Cheston and Guy Lane founded Kabina, a UK company, to work with water not against it. Our ethos is to deliver economic, social and environmental benefits through intelligent innovation. Kabina’s essence is ‘Of our time’.

Kabina's diverse and expert team includes acknowledged naval architects; real estate professionals; urban planners; offsite housing manufacturers; and environmental specialists.

Kabina® is responding to well-documented and accelerating trends: climate change; unprecedented weather events and their consequences; and the need to build new homes for the 21st century.

Kabina’s new flood adaptive smart homes can

  • 1) Make a strong contribution to the UK’s post Brexit economy;
  • 2) Provide net contribution to UK flood mitigation;
  • 3) Reduce construction costs and time, subject to the planning process;
  • 4) Help to resolve the current acute housing crisis;
  • 5) Support 2017 Autumn Budget and Housing White Paper policy objectives; and
  • 6) Reduce UK plc's flooding risk because of climate change.

Ends/

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Get in touch

Guy Lane
Marketing Director
: +44 (0)7798 832576
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Kabina Ltd

13 Hawley Crescent,
London
NW1 8NP