With rainfall patterns changing and sea levels rising, the possible effects of climate change are now an important consideration in any long-term planning. For housing providers, having access to data insights that provide a clear picture of the potential risks associated with flooding is essential to proactively protecting property assets and communities from the threat of flooding.
You only have to look back to the start of 2020 to consider the aftermath created by storms Ciara, Dennis and Jorge, which displaced many people from their homes in just a matter of weeks. In fact, February was the wettest recorded in the UK and with it came an estimated clean-up bill of around £360 million (source: Association of British Insurers).
With future predictions suggesting that we will witness hotter, drier summers and wetter winters, the issue of flooding will only become more prominent. The difficulty is that flooding can occur at any time and in almost any location. A common misconception is that flooding only happens if the site is near to a tidal or flowing water source, such as the sea or a river, or alternatively is situated on low-lying ground; this unfortunately isn’t the case.
As it stands, the Environment Agency estimates that around five million properties in England are at risk of flooding. The type of flood risk varies but most common threats include:
- Fluvial flooding – floods that occur when a river, stream or watercourse is unable to cope with water levels from surrounding land and typically occurs after prolonged rain that has waterlogged the land.
- Pluvial flooding – surface water flooding that results from heavy rain that overwhelms drainage and creates flash floods.
- Coastal flooding – typically results from wet and stormy conditions, high tides or, in the longer term, rising sea levels.
- Groundwater flooding – results from an accumulation of water sources, which leads to water levels rising above natural water-table levels.
- Reservoir flooding – occurs when volumes of water increase to the extent that a reservoir fails, flooding into neighbouring land.
Of these, surface water flooding presents a significant risk. In fact, the Environment Agency suggests that three million properties are at risk of surface water floods, and this is likely to grow, particularly when new housing developments are built. It not only creates further demands on existing drainage systems but also means there is potentially less green space where water can naturally drain to, compounding the issue.
At a time when housing providers are being encouraged to build more homes, it’s important that they not only assess their existing assets to determine their changing environmental risk profiles, but also undertake assessments to understand their future flood risks.
How can you determine your flood risk?
We are fortunate that we have a wealth of data sources that provide accurate insights and intelligence. Importantly, this data doesn’t just provide a view of today’s risks but also gives us credible modelled data on future flood risks.
The starting point should be to access Environment Agency data (or the Scottish Environment Protection Agency) because this provides a high-level view on current risks relating to river, coastal, surface, groundwater and reservoir flood risks for any given area.
For a more specific, address-based analysis, flood reports are available that provide more targeted analysis and allow you to zoom in on highlighted risks to determine type, scale and probabilities. They also provide a view on whether further onsite investigations are needed.
If more detailed investigations are required, a physical flood risk assessment should be undertaken by an environmental consultant who can offer practical solutions on what steps should be taken to either make existing properties resilient or factor in mitigation measures when designing or creating plans for new housing developments, if flooding can’t be ruled out at the address in question.
Predicting risks over time
The UK Climate Projections (UKCP09) indicate that the country is likely to receive increases in rainfall frequency and intensity through climate change. Based on these predictions, it’s expected that the risk posed by flooding will increase, with more severe flood events occurring with greater frequency.
In light of this, flood risk modelling is continuing to evolve. At Landmark, in partnership with Ambiental Risk Analytics and Wales & West Utilities, we have introduced a national GB dataset that incorporates UKCP09 climate projections to enable housing providers, asset managers, local government, utility providers, property developers and others to identify the potential impacts of climate change from a flooding perspective.
By way of background, Ambiental’s data was created using probabilistic climate predictions to generate flood models, which are provided as a range of climate change datasets that can be interrogated. Ambiental’s dataset includes layers for baseline and future scenario flood maps, erosion risk potential and risk to transport for the 2020s, 2050s and 2080s, ultimately supporting the analysis of future flood risks to property across multiple emission circumstances.
The aim is to provide the tools that enable all stakeholders to correctly plan for long-term flood risks with greater clarity and understanding of how risk profiles will change over time.
Having access to such future-facing data not only supports climate change risk assessments and adaptation reporting requirements now, but ultimately also future-proofs the asset and property investments of all involved.
Forewarned is forearmed
It has already been reported that Fairbourne in Wales has the potential to become one of the first places to succumb to the vulnerability of climate change due to rising sea levels. The true physical impact of climate change is something we are only really beginning to fully understand, and to accurately address this risk a data-driven narrative can inform stakeholders of the risks.
Flood risk is one of the greatest environmental threats facing the UK. It therefore pays to do your research to determine exactly what risks are present today and in future to ensure tenants don’t have to deal with the appalling consequences that flood waters bring. In our view, forewarned is most certainly forearmed.
Tom Telford is an account director at Landmark Information.
