Flood risk for your postcode, cited

Common questions

What do Flood Zone 1, 2 and 3 mean in England?

The Environment Agency uses a three-zone system on the Flood Map for Planning. Flood Zone 1 covers land with a less than 1 in 1,000 (0.1%) annual probability of flooding from rivers or the sea — the lowest-risk category, covering roughly 95% of land in England. Flood Zone 2 describes land with a 1 in 100 to 1 in 1,000 annual probability from rivers, or 1 in 200 to 1 in 1,000 from the sea. Flood Zone 3a is the highest-risk category: land with a 1 in 100 (1%) or greater annual probability of river flooding, or 1 in 200 (0.5%) or greater from the sea (Environment Agency, Flood Map for Planning, 2024).

How often does the Environment Agency update flood maps?

The EA updates the Flood Map for Planning periodically. The National Flood Risk Assessment 2 (NaFRA2), published in 2024, is the most recent whole-of-England probability update. Individual flood maps are revised when new modelling data becomes available — typically after major flood events, new infrastructure or improved ground-level survey data. The data shown here is drawn from the EA's OGL bulk polygon datasets, refreshed in this service quarterly.

What is the difference between river flooding and surface water flooding?

River flooding occurs when watercourses overflow their banks after sustained rainfall or snowmelt. Surface water flooding happens when intense rainfall overwhelms drainage systems before it can reach any watercourse — it can affect properties far from any river or coast and occurs rapidly. The EA maps both risks separately. A property can have low river-flood risk but significant surface water risk, which is why this tool shows both zone classification and surface water band.

Does flood risk affect my mortgage or buildings insurance?

UK Finance guidance requires a buildings insurance quotation before completion on any property where flood risk is a material concern. For Flood Zone 3 properties, some high-street lenders apply enhanced underwriting criteria. The Flood Re reinsurance scheme subsidises flood insurance premiums for eligible properties built before 1 January 2009, but properties built on or after that date are excluded (Flood Re scheme rules, 2016, rule 4.1). If insurance is declined or priced above what a lender will accept, the mortgage can fall through after you have paid for surveys and solicitors.

What should I do if my postcode is in Flood Zone 3?

First, confirm the exact classification at the property footprint (not just the postcode centroid) using the EA's 'Check the long-term flood risk for an area in England' service at check-long-term-flood-risk.service.gov.uk. Second, obtain a buildings insurance quote before making an offer — ask whether Flood Re applies. Third, review the local authority's Strategic Flood Risk Assessment (SFRA) for site-specific mitigation measures. Fourth, consider commissioning a Flood Risk Assessment from a qualified flood risk consultant if you proceed. Eavesdrop's full report (£9.99) includes all EA flood layers checked against the property's UPRN.