Future surface water flood risk

The recent Committee on Climate Change 2019 ‘Progress in Preparing for Climate Change’ Report found that as there are currently substantial gaps in understanding of exposure to surface water flooding, better, more targeted data are needed to measure changes in vulnerability.  Surface water flood alleviation is identified as one of the highest national priorities to plan for climate change.

Our urban areas still rely heavily on grey infrastructure which has a limited scope. In the future, sewers and drains will reach capacity sooner and infrastructure, homes and businesses will flood more frequently. Knowing the areas most sensitive to these increases in risk can enable local authorities, government agencies, water companies, communities and individuals to target adaptation planning work, such as retrofitting our urban environment with green and blue infrastructure.

Surface water flood mapping

Currently there is no nationally consistent mapping that shows impact of climate change on surface water flooding. This creates a challenge for understanding the areas that are going to be the most sensitive to this increase in risk at both a national and a local level.

November 2018 saw the release of updated UK Climate Projections (UKCP18), and new high-resolution data was launched in September this year. This is available on a 2.2km grid and will enable more targeted adaptation work. Upon publication of updated Environment Agency guidance to reflect UKCP18 which is expected in 2020, our range of uplifts will enable the user to apply the most applicable to the new guidance.

As a company with a strong sustainability and innovation ethos, we are keen to play our part in addressing the challenge facing adaptation planners. We have an unparalleled track record of providing the Environment Agency with national-scale flood maps since 2004, and the use of our JFlow® software gives us the ability to automate data analysis and produce flood maps covering large areas quickly and efficiently.

Future climate change flood scenarios

We’ve piloted an approach in South East England (covering Hampshire, Sussex and Kent) to create a range of surface water flood maps based on current Environment Agency guidance for different rainfall intensity uplifts for the 2080s. This enables drainage professionals, planners and climate change specialists to understand future flood risk in events with a high, medium and low probability of occurring, the map outputs can be compared against the current Risk of Flooding from Surface Water (RoFSW) map. The user will be able to understand where infrastructure, homes and businesses are most susceptible to future increase in surface water flood risk.

Want to know more?

Local circumstances vary and we have the ability to build different topography, land uses and drainage allowances into our models. We also have the skills and capacity to support climate change adaptation planning and the provision of blue-green infrastructure alongside our local flood risk management services.

Email Rosalind Rogers for more information on our climate change flood mapping and how it can be adapted for your area.

For further information about our local flood risk management services, contact Hannah Coogan.

1 Comment

  • Dr. Nele Jensen

    Hello there

    I am writing with a question about your surface water flood risk methodology in relation to a property we are in the process of buying. Through our solicitors Landmark produced a flood report for us using your company’s modelling data, which identified the flood risk from surface water as moderate to high for our property (39c Carisbrooke Rd, TN38 0JN). Yet, according to the UK flood warning information system, the risk for our property is ‘low’. As both a customer and an academic (with a first degree in Geography), I was hoping you could shed some light on what key differences are between the two different modelling exercises are that may explain these discrepancies (and/or point me to a paper or similar explaining these differences)? Many thanks and best wishes, Nele

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