Flood zones and what they mean

Flood zones give you one type of flood risk information for the planning process.

They are based on a location's chance of flooding from rivers or the sea in any year. They do not take into account:

• other sources of flooding
• future flood risk from rivers or the sea

This means a site in flood zone 1 could still flood now or in the future.

To get a more complete picture of a location's risk, you should check the long term flood risk for an area .

Flood zone 1

Locations in flood zone 1 have a low probability of flooding. This means in any year land has a less than 0.1% chance of flooding from rivers or the sea.

Some flood zone 1 developments need a flood risk assessment as part of their planning application. Find out when you need a flood risk assessment for development in flood zone 1.

Flood zone 2

Locations in flood zone 2 have a medium probability of flooding. This means in any year land has between a 1% and 0.1% chance of flooding from rivers and between a 0.5% and 0.1% chance of flooding from the sea.

Flood zone 2 developments need a flood risk assessment as part of their planning application.

Flood zone 3

Locations in flood zone 3 have a high probability of flooding. This means in any year land has a 1% or more chance of flooding from rivers, or a 0.5% or more chance of flooding from the sea.

Flood zone 3 developments need to submit a flood risk assessment as part of their planning application.