In what seems to be becoming a gruesome seasonal tradition, there is a familiar pattern observed in this winter dance: days of heavy rain; TV pictures of homes inundated and lives ruined; tales of brave rescues and endurance; until finally, a spate of articles bemoaning the unbelievable greed and complacency of developers, the government and planners in building homes in the flood plain in the first place.
In the decade to 2016, according to an analysis of government data by Loughborough University academic Lee Bosher, just under one in every ten new homes was built in an area of high flood risk – flood zone three according the Environment Agency's ranking. That's well over 100,000 homes.
In a world where climate change is raising sea levels and making storms more severe and more frequent, this seems instinctively crazy. But it is also unlikely to change. Towns and cities are largely built around rivers, meaning much of the best located and most sustainably-located land comes with a degree of flood risk. Put a blanket ban on all these sites and you will blight many urban areas and put ever greater pressure on greenfield and green belt sites.
The pertinent questions for authorities, therefore, are on which sites can flood risk can be mitigated, and how to judge whether proposals will achieve that. There are certainly many ways developments can reduce flooding risk. At a whole development level, it is about making space for the water to go to in times of flood, with swales and other green features designed to be inundated. Smart developers know these features can, if done well, contribute to biodiversity. In response, authorities may need to be relaxed about density stipulations – green infrastructure will commonly take a lot of space.
At an individual house level this is about designs which take living space off the ground floor, including homes on stilts like the Oakfield development in Stratford-Upon-Avon. Consultant Floodline is also promoting the idea of "Can Float" homes in the UK, which actually lift when water levels are high. Design codes may need to be flexed to allow unusual housing forms.
The difficulty for authorities is that there is no accepted building standard for flood resilient housing. A Riba proposal last year for new building regulations covering flood resilience, to be applied in flood risk areas, hasn't been acted upon. While the Environment Agency provides advice to planning authorities on flood risk and how to mitigate it, the lack of a construction standard means that when authorities do currently consider applications for homes on the flood plain, planning authorities find it hard to judge the good schemes from the bad
Developers expert in this area say that currently many sites are being thrown out by local authorities on the precautionary principle, when the risks could easily be managed. At the same time, other applications are being approved, when it is not always clear what mitigations have been undertaken.
While all involved agree there must be a better way, in the meantime authorities may have to take an authority-wide view about how climate change will affect them, and really interrogate developers' understanding of flood risks – or else risk sterilising vital urban sites from development.
Joey Gardiner is special correspondent for Planning