Flood Risk Maps UK
Search any UK location to check flood zones, surface water risk, defences and historic flooding before you buy, plan or develop.
Updated: quarterly for flood zones · Last checked by Maplify: August 2026
What This Layer Shows
This layer maps Environment Agency flood data across 18 layers: Flood Zone 2 and 3 for river and coastal flooding, three levels of surface water (pluvial) flood probability, reservoir flood extents, flood defences and the areas benefiting from them, flood alert and warning areas, and the historic flood map showing where flooding has occurred before.
Over 5.2 million properties in England are estimated to be at flood risk, which is why flood zone checks are routine for property buyers, developers, mortgage lenders and local planning authorities.
Why It Matters
Flood risk affects mortgage availability, insurance cost, and — for Flood Zones 2 and 3 — whether a planning application must pass the Sequential and Exception Tests before development can proceed. Buyers, developers and planning consultants check this layer early because it can materially change a site's viability.
Because surface water flooding depends on local drainage rather than proximity to a watercourse, a site can carry meaningful flood risk even when it sits well outside a formal river flood zone, making it easy to overlook without checking the dedicated surface water layers.
How to Interpret the Map
Flood Zone 2
Medium probability of river or sea flooding — 0.1%–1% annual chance (river) or 0.1%–0.5% (sea).
Flood Zone 3
High probability — 1%+ annual chance (river) or 0.5%+ (sea). Triggers the Sequential and Exception Tests.
Surface water (high/medium/low)
Pluvial flood probability from rainfall overwhelming drainage, independent of river proximity.
Flood Risk Layers in the Maplify Map
Planning and Development Implications
Development in Flood Zone 2 or 3 must pass the Sequential Test — demonstrating no reasonably available lower-risk site — and, for more vulnerable uses in Zone 3, the Exception Test, alongside a site-specific Flood Risk Assessment addressing surface water, defences and climate change allowances.
Surface water risk, while not subject to the same statutory tests, is increasingly scrutinised by local authorities and can require sustainable drainage (SuDS) measures even outside a formal river flood zone.
What to Do When a Site Is Affected
- 1
Confirm the exact flood zone and surface water rating with the Environment Agency's flood map for planning.
- 2
Commission a site-specific Flood Risk Assessment for any Zone 2 or 3 site proposed for development.
- 3
Check whether flood defences apply and understand the residual risk if they were overtopped.
- 4
Factor SuDS and climate change allowances into the drainage strategy from the outset.
- 5
Confirm mortgage and insurance implications with lenders and insurers before exchange.
This is general guidance, not professional or legal advice — confirm specifics with the relevant authority or a qualified professional.
Official Data Source
Data Freshness
Important Limitations
- Flood maps are modelled estimates and are indicative, not a guarantee of what will happen in any specific rainfall or flood event.
- Being outside a mapped flood zone does not mean a site can never flood — surface water and local drainage issues can still occur.
- Flood defences reduce risk but can be overtopped or fail; residual risk still applies to areas benefiting from defences.
- This map does not replace a site-specific Flood Risk Assessment required for planning applications in Flood Zones 2 and 3.
Common Use Cases
Property Buyers
Check flood risk before making an offer, including for mortgage and insurance purposes.
Property Developers
Screen sites for Sequential/Exception Test exposure before acquisition.
Planning Consultants
Scope Flood Risk Assessments and SuDS requirements for a scheme.
Surveyors
Factor flood zone and surface water risk into valuation reports.
Related Layers
Flood risk is one of several checks worth running together for a site.
Related Guides
Frequently Asked Questions
What does the flood risk map show?
It shows Environment Agency flood zones 2 and 3, three levels of surface water (pluvial) flood probability, reservoir flood extents, historic flood outlines, flood defences and flood warning areas, all on the same interactive map.
What is the difference between river flooding and surface water flooding?
River (fluvial) and coastal flooding follow watercourses and tidal areas and are shown as Flood Zone 2 and 3. Surface water (pluvial) flooding happens when rainfall overwhelms drainage and can occur anywhere, including areas well outside a river flood zone.
How often is the flood data updated?
Flood zone boundaries are refreshed quarterly from the Environment Agency; surface water, reservoir and historic flood layers are updated periodically as the Environment Agency republishes them.
Does this map replace a Flood Risk Assessment for planning?
No. Planning applications in Flood Zones 2 and 3 normally require a professional Flood Risk Assessment. Maplify is a screening tool to identify risk early, not a substitute for that assessment.
Can I check flood risk for a specific property rather than browsing the whole map?
Yes — use the postcode search to jump straight to a site, or use our dedicated Flood Risk Check page for a single-property workflow.
Do flood defences remove the risk entirely?
No. Defences reduce risk but can be overtopped or fail; areas benefiting from defences still carry residual risk that is reflected in the mapping.
Check Flood Risk on Maplify
Search any UK location to view flood zones, surface water risk and defences alongside property and planning data.
Dataset Details
| Provider | Environment Agency |
| Geometry type | Polygon |
| Coverage | England |
| Update schedule | Quarterly for flood zones; periodic for other layers |
| Reference date | August 2026 |
| Licence | Open Government Licence v3.0 |