Environment Agency
Flood Risk by Postcode (Rivers and Sea)
For every postcode in England with property in a mapped flood area, how many homes and business premises sit at high, medium, low or very low risk of flooding from rivers and the sea — the Environment Agency's own national assessment, rebuilt in 2025.
At a glance
- Publisher
- Environment Agency
- Licence
- Open Government Licence v3 — Credit the Environment Agency. · what this means
- Updates
- Updated occasionally
- Cost
- Free — open data
- Last checked
- 2026-10-14
InsurancePropertySolicitors & conveyancingFinancial servicesFlood & ground risk
What your business can use it for
- Risk assessmentScreen a book of properties, a list of loan applications or a set of sites for river and sea flood risk before you insure, lend, buy or sign — by postcode, with no mapping software.
- Property valuationFlood risk moves what a property is worth and whether it can be insured or mortgaged. Flag it alongside the comparables before the valuation goes out.
- Site selectionRule out candidate premises in high-risk postcodes before you spend money on viewings and surveys.
Works with data you already have
- Property, client or site postcodes you holdPostcodesColumn PC, one row per postcode with property in a flood band. Normalise case and spacing, and route old postcodes through the free ONS postcode lookup.
How to get it
- Risk of Flooding from Rivers and Sea — Postcodes in Areas at Risk (one CSV for all of England)Bulk downloadNo account needed. A 5 MB zip holding one CSV of about 270,000 postcodes, plus the Environment Agency's product description. Republished as the national model is updated — the Environment Agency plans every three months.
- Check your long term flood risk — look up one addressPortalThe public service built on the same assessment, including surface water. Good for a single property; for a list of postcodes, use the download.
What's involved in using it
- It counts properties per risk band in each postcode — it does not say which property is which. Matched to your address list, it tells you a property sits in a postcode with flood risk, not that the property itself will flood.
- The columns delivered don't quite match the Environment Agency's own published description, and there are extra total columns the description doesn't explain, so they need checking before anyone builds a percentage on them.
- A postcode missing from the file has no property in a mapped river or sea flood area — that is an answer, not a failed match. Retired and newly issued postcodes have to be routed through the free ONS postcode lookup before you can tell the two apart.
The technical detail, for whoever sets it up (4)
- Rivers and the sea only. Surface water, groundwater and sewer flooding are not in this file, and no postcode-level version of them is published.
- England only. Wales, Scotland and Northern Ireland each publish their own flood maps.
- The Environment Agency says this assessment was not designed or tested for underwriting or setting insurance premiums.
- Rebuilt in 2025 on a new method and a finer map, so a postcode that has changed band since an older download may reflect the new model rather than a real change.
Ask us about Flood Risk by Postcode (Rivers and Sea)
Ask a factual question about Flood Risk by Postcode (Rivers and Sea) — what it covers, how often it changes, whether it matches the records you keep — and we will answer, free. Or tell us what you are trying to work out, and we will tell you what it would take to get this data working next to the numbers you already have.