Is Flood Risk Data Public Record? How to Check It (England & Wales)

Table of Contents

• Who Holds Flood Risk Data and What It Covers
• How to Check Long Term Flood Risk for Any Postcode
  • Reading the Four Flood Risk Categories
• River, Sea and Surface Water: What the Maps Show
• What a Flood Risk Assessment for Property Does and Does Not Cover
• Recorded Floods and the Data Behind the Maps
• How Flood Risk Data Sits Inside a Wider Area Check
• Common Mistakes When Reading Flood Data Yourself
• Conclusion
• Frequently Asked Questions

Last Updated: September 30, 2026

Who Holds Flood Risk Data and What It Covers

Flood risk data is public record in England and Wales, and you can read it for free. The Environment Agency publishes the long-term flood risk for any postcode, and anyone can search it without an account (Check the long term flood risk for an area in England). This guide from JACKSON explains what each dataset covers and where it stops.

Three bodies hold the main records:

• The Environment Agency holds river, sea and surface water risk for England
• Natural Resources Wales holds the equivalent maps for Wales
• Lead local flood authorities hold records of past flooding in their area

Scotland and Northern Ireland run separate systems, so the steps below do not apply there.

That is the good news. The catch is that the maps show risk, not a verdict on a specific house.

How to Check Long Term Flood Risk for Any Postcode

Checking long-term flood risk takes about five minutes. Go to the government's flood risk service, type in the postcode and read the result for the exact address, not the wider area.

The steps are simple:

1. Open the government long term flood risk service and enter the postcode
2. Select the specific address from the list
3. Read the four risk bands for rivers and sea, and for surface water
4. Check the separate section on groundwater and reservoirs
5. Note the date shown, because the data updates on a rolling basis

The result is a band, not a guarantee. A "low" rating still means flooding is possible.

Reading the Four Flood Risk Categories

Each address gets a band for rivers and sea, and a band for surface water. The bands run from very low to high, based on the chance of flooding in any given year.

• Very low: less than 1 in 1,000 chance each year
• Low: between 1 in 1,000 and 1 in 100
• Medium: between 1 in 100 and 1 in 30
• High: greater than 1 in 30

Surface water uses the same four bands. A property can sit in a low river band and a high surface water band at once, which is common in towns.

River, Sea and Surface Water: What the Maps Show

The maps model three different sources, and each behaves differently. River flooding follows watercourses and can arrive with warning. Sea flooding depends on tides and storm surge. Surface water flooding happens when drains cannot cope with heavy rain.

Surface water is the one buyers underestimate. It can strike anywhere, not just near a river, and it often hits low spots in a street that look harmless on a dry viewing day.

The maps also flag areas protected by defences. A defence reduces risk but does not remove it, and defences can be overtopped in an extreme event.

What a Flood Risk Assessment for Property Does and Does Not Cover

A flood risk assessment for property is a site-specific study of how water could reach a building. It models flow paths, depths and defences for one plot, and it is usually required for new build or major extension planning.

What it covers:

• The flood zone for the site under national planning policy
• Expected flood depth and speed in a modelled event
• Access and escape routes during a flood
• Mitigation measures, such as raised floor levels

What it does not cover:

• The condition of the building or its drains
• Subsidence, damp or structural faults
• Insurance terms or premiums

JACKSON is not a survey and does not assess the condition of any building. An area report sits alongside a survey, never instead of it.

Recorded Floods and the Data Behind the Maps

Recorded flood outlines show where flooding has actually happened, not where it might. The Environment Agency keeps historic outlines from past events, and these sit next to the predictive maps.

Run a free area check →

The two tell different stories. A property outside the modelled risk area may still sit inside a recorded flood outline from an older event, because the maps change as modelling improves.

What most guides miss is the date on each record. An outline from a decade ago may reflect a defence that has since been built, or a culvert that has since been cleared. Always read the date before you draw a conclusion.

How Flood Risk Data Sits Inside a Wider Area Check

Flood risk is one layer among many, and reading it alone gives a narrow view. A full picture combines flood, crime, noise, planning and sold prices for the same postcode.

At JACKSON, we pull those official datasets into one report for any postcode in England and Wales. Every figure carries its source and date, and on the person-checked tiers a named analyst reads and signs the verdict before it goes out.

Here is how the layers compare:

The free Viewing Check gives you a first look. The Instant Report costs £9, and the person-checked Area Report starts from £19.

Common Mistakes When Reading Flood Data Yourself

The biggest mistake is checking the postcode instead of the address. Risk bands change street by street, and a postcode-wide result can hide a property that sits in a high surface water band.

Other common errors:

• Ignoring surface water because the property is nowhere near a river
• Assuming a defence removes all risk
• Reading an old printout and treating it as current
• Confusing a flood risk assessment with a building survey
• Overlooking groundwater and reservoir risk, which sit in a separate section

A common mistake is to treat a "low" band as a clean bill of health. Low is not none.

The same discipline applies to the other layers. A cheap asking price near a flood outline is not automatically a bargain or a trap. It is a question that needs data, not a guess.

Conclusion

Reading flood data yourself is free and worth doing, but the maps only answer part of the question. They show modelled risk, not what a specific house will do in the next storm.

JACKSON was built to put that data in context for the area you are looking at. Every report combines flood, crime, noise, planning and sold price data for one postcode. Each figure carries its source and date; the Instant Report lands in minutes, and on the person-checked tiers a named analyst reads and signs the verdict within one working day. Start with the free check and see what the data says before you commit.

Frequently asked questions