Flood Zone 1 means land which has a less than a 1 in 1000 annual probability (chance) of river or sea flooding (<0.1%).
Where do I find this information?
Flood Zones form part of the Environment Agency's Flood Map. Flood Zone 1 is shown by the unshaded area on the Flood Map. This information is provided to Local Planning Authorities on the Flood Map CD.
The Environment Agency contacts Local Planning Authorities quarterly either to update the information on the Flood Map or to confirm that there have been no changes to the Flood Map information for that Authority's area. Flood Map is also available to view on the Environment Agency's website at www.environment-agency.gov.uk.
Dry Islands
There are some areas classified as falling within Flood Zone 1 that are surrounded by areas at a higher risk of flooding i.e. areas falling within Flood Zones 3 and 2.
In certain cases development within such 'dry islands' can present particular hazards to public safety and risks such as those risks associated with maintaining safe access and exit for occupants during flood events. The distribution of dry islands and risks posed by them in terms of access/exit vary considerably across the country. If you are in any doubt about how flood risks associated with 'dry islands' may affect your Authority area, please contact your local Environment Agency Planning Liaison team.