Where to look first

For a property in England, the government’s long-term flood risk service is a good starting point. It covers flooding from rivers and the sea, surface water, reservoirs and groundwater where information is available. There are separate services for Wales, Scotland and Northern Ireland. The site links to all four below.

Why the map is not the whole answer

A mapped risk describes an area rather than predicting what will happen to your particular house. Ground levels, thresholds, local drains, extensions and walls can make a real difference. A street may be dry while one low-lying property floods. Equally, a low mapped risk is not a guarantee of safety.

Look for evidence on the ground

Examine the slope of the driveway and garden. Is the front door lower than the road? Does rain regularly gather against the wall? Are there low air bricks, basement steps or a garage below road level? Ask carefully about previous flooding when buying a property.

Check past events separately

Historic flooding is useful evidence, but a house that has never flooded can still be exposed. Drainage changes, new development and more intense rain may alter conditions. Speak to neighbours, the council and your insurer where appropriate.

What to do with the result

If your risk is significant, sign up for relevant flood warnings and make a household flood plan. If the problem appears local to your home, a competent drainage specialist may help investigate gullies, pipes and surface-water disposal.

Useful official checks

England: long-term flood risk. Wales: Natural Resources Wales. Scotland: SEPA flood maps. Northern Ireland: Flood Maps NI.

Consider more than one kind of flooding

A property may be exposed to river water, coastal flooding, surface water collecting in a low spot, groundwater or drains surcharging during heavy rain. Each behaves differently. A river warning service will not necessarily identify a blocked private gully or water running off a neighbour’s raised patio. Use the official map as a starting point, then examine the property itself, particularly thresholds, low-level vents, below-ground rooms and routes from roads or sloping land.

What to keep as evidence

Take photographs of ponding during ordinary storms and record the approximate weather conditions, duration and whether multiple drains were affected. Speak to neighbours about flooding in the street, although their experience may differ from yours because ground levels vary. If you are planning protection works, ask the surveyor to identify likely water-entry routes, expected depths and safe limits for resisting water pressure. That makes a far more useful specification than buying a barrier just because an online map shows an elevated risk.

What a flood-risk map can miss

A long-term flood-risk map is a starting point, not a guarantee about an individual doorway or garden. The model may show risks from rivers, the sea or surface water, but it cannot account for every blocked gully, recently raised driveway or small change to local ground levels. An address at low mapped risk can still suffer a very local flood. Equally, being within a coloured area does not mean that a house will inevitably take in water. Check which kind of flooding the map describes and whether the information is about today’s conditions or longer-term likelihood. Those are two quite different questions.

Look at the site itself. Is the ground floor below the pavement? Does the garden fall towards the rear door? Are there airbricks or a basement close to ground level? A neighbouring property can have a different exposure despite being on the same street. If you are buying, ask direct questions about previous flooding and obtain specialist advice where the history or physical layout warrants it.

Turn the result into a sensible plan

Keep a copy of the risk information and note when you checked it. Sign up for official warnings wherever the service is available, but remember that some flash surface-water events cannot be predicted precisely at property level. Check your insurer’s flood terms, especially excesses and any exclusions, before you have to make a claim. Make a list of important documents, medication, essential equipment and people who may need help if you have to leave quickly.

If the property has a recurring problem, obtain a survey that identifies the route water takes and any weak points. A contractor should explain why a proposed measure is suitable: a door barrier will not remedy an overflowing public sewer, and a new soakaway may be ineffective in saturated or unsuitable ground. The right decision follows from the specific source of the water, not simply the flood-risk rating shown on a map.

Reliable further information

For current warnings, official flood-risk maps and safety advice, use the relevant government service. This website cannot assess live conditions at your home.

Government flood guidance · National Flood Forum · Citizens Advice