Data and methodology
What the flood map shows
The map is a visual guide to published flood-risk coverage. These notes explain the source data, how it is displayed and where its limits begin.
Environment Agency flood-risk data
The flood layers use the Environment Agency National Flood Risk Assessment 2 (NaFRA2) for England. The current map release uses rivers and sea data dated January 2026 and surface-water data dated September 2025.
The two products remain separate in the map:
- Rivers and sea shows mapped risk associated with watercourses and coastal flooding.
- Surface water shows mapped risk when rainfall collects or flows over the ground.
Reading the risk bands
Each dataset is displayed in four published bands: High, Medium, Low and Very low. Use the labels in the map key as the guide. The bands describe modelled likelihood across an area; they are not a forecast and they do not state the expected depth at an individual property.
At wider zoom levels, geometry is simplified and dissolved to keep the national view responsive. Zoom level 14 and closer uses the detailed source polygons. Very narrow features may not be visible when zoomed out.
Search and background mapping
Place, street and postcode suggestions use OS Open Names and are limited to England. The background map uses OpenStreetMap-derived vector data styled with Protomaps. Full attributions are available from the information control on the map.
Licensing
Environment Agency information is used under the Open Government Licence v3.0. Location search contains OS data © Crown copyright and database right 2026. OpenStreetMap data is available under the Open Database Licence; the map attribution control contains the required credits.
Official checks and updates
For an official property-oriented starting point, use the government’s long-term flood-risk service. A new Flood Risk Map release will be versioned when its underlying data changes. The dataset dates above will be updated with it.
Questions about processing or an apparent display problem can be sent to hello@floodriskmap.co.uk.