Flood Risk Screening Portfolio for a Major Housing Provider
3 minutes reading time
A large housing group managing an extensive residential portfolio across the South East of England, including both coastal and inland properties, approached us to assess the potential exposure of its housing stock to both present-day and future climate-related risks.
This project was undertaken by a multidisciplinary team within our consultancy.
James Robinson, Ana Braid, Ian Walkington and Seb Martin.
Project Overview
The Challenge
With increasing frequency and severity of extreme rainfall events, the client required a clear, evidence-led understanding of flood risk across their entire housing portfolio.
The objective was not only to understand present-day exposure, but also how climate change could alter flood risk over the lifetime of the assets, enabling informed strategic decision-making around investment, mitigation, and long-term asset management.
Given the scale of the portfolio, the client needed a solution that could:
-Assess thousands of properties consistently
-Compare risk across multiple flood sources
-Quantify financial impact
-Present results in a format suitable for both technical and non-technical stakeholders
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The Approach
GeoSmart undertook a portfolio-wide flood risk screening exercise, assessing 12,856 residential properties across the South East of England.
The assessment was informed by FloodSmart Analytics, incorporating high-resolution flood data from all relevant sources, including fluvial, tidal, pluvial and groundwater flooding. Each property was assessed against multiple return periods and assigned a FloodSmart Risk Index, allowing straightforward comparison across the portfolio.
To support long-term resilience planning, future flood risk was also modelled using high-emissions climate change scenarios for the 2030s, 2050s, 2080s. This enabled the client to understand not only where flood risk exists today, but how risk is likely to evolve over time.
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Key Findings
Most of the portfolio currently falls within Negligible to Low flood risk categories, providing reassurance at a portfolio scale. A small but significant proportion of assets were identified as Medium, High or Very High risk, requiring closer attention.
Flood risk varies considerably by source, with surface water and groundwater flooding emerging as key contributors in specific locations. Climate change modelling showed a gradual increase in the number of properties exposed to higher levels of flood risk, particularly by the 2050s and 2080s, highlighting the importance of forward-looking resilience planning.
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Outputs
-An interactive dashboard, allowing property-level interrogation of FloodSmart Risk Index scores
-Climate-adjusted risk
-Estimated Annual Average Damages
A visually led presentation, summarising:
-Portfolio-wide risk distribution and key trends under climate change
-Priority risk areas
These outputs were designed to support both technical analysis and strategic discussion.
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Impact and Value
The flood risk screening provided the client with a robust, consistent evidence base to:
-Prioritise assets for more detailed Flood Risk Assessments and target mitigation and resilience measures where they will have the greatest impact
-Periodically review portfolio risk as data and climate projections evolve
-Consider long-term asset strategies, including divestment where risk is persistent, and mitigation is not viable
By translating complex flood data into clear, comparable insights, the project enabled the client to move from reactive risk awareness to proactive, portfolio-level risk management.
If you are managing a large portfolio of sites and need to consider associated environmental risks, get in touch and we can discuss how we can help.
GeoSmart Information Ltd (Technical Advisors)
info@geosmartinfo.co.uk
01743 581415
www.geosmartinfo.co.uk
