Flood Zone 1 covers most of England. Here is what it means, and when a flood risk assessment is still needed. Paste an address or postcode below to check its zone, or a whole list.
Quick answer
Flood Zone 1 is land in England with a low probability of flooding from rivers or the sea: less than a 0.1% (1 in 1,000) chance each year. It is everywhere outside Flood Zones 2 and 3, most of England, and it is where planning policy steers new development first. A flood risk assessment is still needed for sites of 1 hectare or more, and for a few others.
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For sites of 1 hectare or more; for land the Environment Agency has flagged with critical drainage problems; for land the council's strategic flood risk assessment shows at increased flood risk in future; and for land at risk from other sources of flooding where the development would bring in a more vulnerable use.
Flood Zone 1 is about rivers and the sea only. Heavy rain overwhelming drains (surface water), groundwater and sewers can flood homes in Flood Zone 1, and more properties in England are at risk from surface water than from rivers and the sea. The Environment Agency maps surface water risk separately.
All uses are appropriate in Flood Zone 1 as far as flood zones go: no sequential or exception test is needed on flood zone grounds.
A guide and a screening check, not a flood risk assessment. For a planning application, get the official flood map for planning report for the site from GOV.UK.
What does Flood Zone 1 mean?
Land with a low probability of flooding from rivers or the sea: less than a 0.1% (1 in 1,000) chance each year.
Is Flood Zone 1 safe?
It is the lowest flood zone for rivers and the sea, but not risk-free: surface water from heavy rain can still flood it.
Do I need a flood risk assessment in Flood Zone 1?
Only for sites of 1 hectare or more, land with critical drainage problems, land at increased future risk in the council strategic flood risk assessment, or land at risk from other sources where the use becomes more vulnerable.
Do I need flood insurance in Flood Zone 1?
Flood cover is normally part of buildings and contents insurance in the UK, so there's nothing separate to buy.