Detailed local flood mapping made available through GOV.UK digital services

The Environment Agency is making its detailed local flood mapping available through GOV.UK digital services from early 2025, as part of a new National Flood Risk Assessment (NaFRA) for England published in its national assessment of flood and coastal erosion risk¹. The assessment states that the last full update to NaFRA was in 2018, and that the new version provides a single picture of current and future flood risk from rivers, the sea and surface water¹.

The new assessment finds that around 6.3 million properties (homes and businesses) in England are in areas at risk of flooding from one or a combination of sources, and that with climate change this could increase to around 8 million by mid-century¹. Around 2.4 million properties are in areas at risk from rivers and the sea, slightly fewer than the previous assessment, while properties in areas at high risk from rivers and the sea increase to 367,900, an 88% increase from the previous assessment¹. Of those at high risk, 163,300 are likely to flood to depths of 30cm or higher, and 87,500 to depths of 60cm or higher¹. For surface water, around 4.6 million properties are in areas at risk, a 43% increase on the previous assessment, which the Agency attributes almost entirely to improvements in data, modelling and technology rather than a real-world increase in risk¹.

The mapping itself changes in resolution. The better modelling in the new NaFRA provides a 2 metre resolution, where the current Risk of Flooding from Rivers and Sea maps are limited to a 50 metre resolution¹. The Agency says it does not include groundwater flooding because there are too many gaps in its understanding and evidence for groundwater flood risk at this time, and that NaFRA was not developed or tested for insurance underwriting or setting insurance premiums¹.

The assessment also sets out a timetable for related services¹:

The same assessment reports updated coastal erosion figures: 3,500 properties are in areas at risk of coastal erosion in the period up to 2055, rising to about 10,100 in the period up to 2105, with about half residential¹. It also records that during storms Babet and Ciarán the Agency issued over 750 flood warnings including 5 severe flood warnings, and that flood defences protected around 250,000 properties over winter 2023 to 2024, with around 5,000 properties flooded¹.

Why it matters for households

Households in England can expect the detailed local mapping behind these national figures to appear on GOV.UK services from early 2025, with the new NaFRA data on the Check your long term flood risk service in early 2025 and the flood map for planning updated in spring 2025¹. The assessment notes wide regional variations in flood risk and says the local mapping "will help our customers understand what this new information means for them"¹. Because the surface water totals rise largely through better data and modelling, a property's shown risk may change without any change on the ground¹. The Agency states that NaFRA was not developed or tested for insurance underwriting or setting insurance premiums, and that insurers use their own underwriting methodologies¹. The assessment does not include groundwater flooding¹. For households checking their position, the site's guides on checking your home's flood risk by postcode and on flood alerts, flood warnings and severe flood warnings set out how the published risk information and warning service work, and making a household flood plan covers preparing for flooding.

What happens next

The new NaFRA data is due on the Check your long term flood risk service and on data.gov.uk in early 2025, and the flood map for planning service is due to be updated in spring 2025¹. The Agency says it is committed to a rolling programme of data improvements and is developing a new flood and coastal investment programme using the new NaFRA and the updated National Coastal Erosion Risk Map¹.