Environment

Flood risk by postcode

For every postcode in England with homes or businesses at risk of flooding from rivers or the sea, how many properties are in each band of risk, flood defences included, from the Environment Agency.

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Published by
Environment AgencyOffice for National Statistics
Level of detail
Postcode (map point level)
Published for
Map point
Covers
England
Updates
Quarterly
Data period
Not recorded for this layer. The dates below are when it was published and fetched.
Published
7 September 2026
Fetched by Open Index
19 October 2026
Licence
Open Government Licence 3.0

Where it covers

  • England
  • Wales(not covered)
  • Scotland(not covered)
  • Northern Ireland(not covered)

Natural Resources Wales publishes flood risk as maps, not by postcode. The flood zones layer covers Wales.

SEPA publishes flood maps, not figures by postcode.

Northern Ireland's flood maps aren't open data.

How it is made

Open Index shows the figures as Environment Agency and Office for National Statistics publish them, for the areas they were published for: map points.

Larger areas use the publisher’s own figures, never an average of smaller areas.

Before you use it

  • Each point is a postcode in England with at least one home or business in an area at risk of flooding from rivers or the sea. It is coloured by the highest band any of its properties is in, and lists how many are in each band.
  • High risk is a chance of 3.3% (1 in 30) or more each year; medium, 1% to 3.3%; low, 0.1% to 1%; very low, under 0.1%. These take flood defences and their condition into account.
  • A postcode in England that is not on the map has no property in any band. That is not a promise it will never flood, and surface water from heavy rain is mapped separately.
  • This is the Environment Agency's national assessment for areas, not a survey of any building. For one property, check the Environment Agency's long term flood risk service.
  • Wales and Scotland publish flood risk as maps only. The flood zones layer covers England and Wales, ignoring defences.

Colours on the map

Each point on the map, in one colour

Sources and licences

Risk of Flooding from Rivers and Sea: Postcodes in Areas at Risk
Environment Agency
Edition
Postcodes in Areas at Risk 2026-06-18
Published
18 June 2026
Fetched by Open Index
19 October 2026
Licence
Open Government Licence 3.0
Credit line

© Environment Agency copyright and/or database right 2025. All rights reserved. Some features of this map are based on digital spatial data from the Centre for Ecology & Hydrology, © NERC (CEH). © Crown Copyright and Database Rights 2025 OS AC0000807064. This product is produced in part from PAF® and Multiple Residence Data, the copyright in which is owned by Royal Mail Group Limited and/or Royal Mail Group plc. All rights reserved. Licence number AC0000807064

ONS Postcode Directory
Office for National Statistics
Edition
ONSPD_AUG26
Published
7 September 2026
Fetched by Open Index
15 October 2026
Licence
Open Government Licence 3.0
Credit line

Source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026.

  • Northern Ireland (BT) postcodes are licensed for internal business use only. They stay in the warehouse, marked restricted, and never reach a published file..

Use this data

GET /v1/layers/flood-risk-postcode

This snapshot has no download for this layer yet. The catalogue CSV lists every layer with its dates, coverage and credit line.