National Planning Policy Framework, Annex F: Managing flood risk and coastal change

Table 1: Flood zones (risks from river and sea flooding)

Flood Zone	Definition
Zone 1 Low probability	Land having a less than 0.1% annual probability of river or sea flooding (all land outside Zones 2, 3a and 3b).
Zone 2 Medium probability	Land having between a 1% and 0.1% annual probability of river flooding; or land having between a 0.5% and 0.1% annual probability of sea flooding (land shown in light blue on the Flood Map for Planning).
Zone 3a High probability	Land having a 1% or greater annual probability of river flooding; or Land having a 0.5% or greater annual probability of sea flooding (land shown in dark blue on the Flood Map for Planning).
Zone 3b Functional floodplain	This zone comprises land where water from rivers or the sea has to flow or be stored in times of flood. The identification of functional floodplain should take account of local circumstances and not be defined solely on rigid probability parameters. Functional floodplain will normally comprise: - Land having a 3.3% or greater annual probability of flooding, with any existing flood risk management infrastructure operating effectively; or - Land that is designed to flood (such as a flood attenuation scheme), even if it would only flood in more extreme events (such as 0.1% annual probability of flooding). Local planning authorities should identify in their strategic flood risk assessments areas of functional floodplain and their boundaries accordingly, in agreement with the Environment Agency (not separately distinguished from Zone 3a on the Flood Map).

Note: Flood Zones 2 and 3, shown on the Environment Agency’s Flood Map for Planning, only account for river and sea flooding, and do not account for the benefits of flood defences or the possible effects of climate change. Reference should therefore also be made to the Environment Agency’s other data on the Flood Map for Planning, and any current strategic flood risk assessment(s), when considering potential future flood risks to developments and land uses.

Table 2: Flood risk vulnerability classification

Essential infrastructure

• Essential transport infrastructure (including mass evacuation routes) which has to cross the area at risk.
• Essential utility infrastructure which has to be located in a flood risk area for operational reasons, including for electricity generation and storage, electricity network infrastructure, telecommunications infrastructure, water supply reservoirs and water treatment works that need to remain operational in times of flood.
• Wind turbines.
• Solar farms.
• Hydrogen production facilities.
• Carbon Capture, distribution and storage facilities.
• Heat networks.
• Data Centres.
• Electric vehicle charging stations.

Highly vulnerable

• Police and ambulance stations, fire stations and command centres.
• Emergency dispersal points.
• Basement dwellings.
• Caravans, mobile homes and park homes intended for permanent residential use.
• Installations requiring hazardous substances consent or which fall under The Control of Major Accident Hazards Regulations 2015. Where there is a demonstrable need for such installations – including bulk storage associated with port or similar facilities, and energy infrastructure and carbon capture or storage – to be located at coastal, water-side, or other high flood risk areas, they should be classified as ‘Essential Infrastructure’.
• Installations requiring a radioactive substances regulations permit for disposal to landfill or dedicated near-surface disposal by burial.

More vulnerable

• Hospitals.
• Residential institutions such as residential care homes, children’s homes, social services homes, prisons and hostels.
• Buildings used for dwelling houses (including floating/rising designs), student halls of residence, drinking establishments, nightclubs and hotels.
• Non–residential uses for health services, nurseries and educational establishments.
• Landfill^{[footnote 78]} and sites used for waste management facilities for hazardous waste.
• Sites used for holiday or short-let caravans and camping, subject to a specific warning and evacuation plan.

Less vulnerable

• Police, ambulance and fire stations which are not required to be operational during flooding.
• Buildings used for: shops; financial, professional and other services; restaurants, cafes and hot food takeaways; offices; general industry, storage and distribution; non-residential institutions not included in the ‘more vulnerable’ class; and assembly and leisure.
• Land and buildings used for agriculture and forestry.
• Waste treatment (except landfill and hazardous waste facilities).
• Minerals working and processing (except for sand and gravel working).
• Water treatment works which do not need to remain operational during times of flood.
• Sewage treatment works, if adequate measures to control pollution and manage sewage during flooding events are in place.
• Car parks.
• Land-raising (unless part of or enabling a development with a higher vulnerability classification).

Water-compatible development

• Flood control infrastructure.
• Water transmission infrastructure and pumping stations.
• Sewage transmission infrastructure and pumping stations.
• Sand and gravel working.
• Docks, marinas and wharves.
• Navigation facilities.
• Ministry of Defence installations.
• Ship building, repairing and dismantling, dockside fish processing and refrigeration and compatible activities requiring a waterside location.
• Water-based recreation (excluding sleeping accommodation).
• Lifeguard and coastguard stations.
• Amenity open space, nature conservation and biodiversity, outdoor sports and recreation and essential facilities such as changing rooms.
• Essential ancillary sleeping or residential accommodation for staff required by uses in this category, subject to a specific warning and evacuation plan.

Table 3: Flood risk vulnerability and flood zone ‘incompatibility’

Flood zones	Flood Risk Vulnerability Classification
	Essential infrastructure	Highly vulnerable	More vulnerable	Less vulnerable	Water compatible
Zone 1	yes	yes	yes	yes	yes
Zone 2	yes	Exception test required	yes	yes	yes
Zone 3a †	Exception test required †	no	Exception test required	yes	yes
Zone 3b ††	Exception test required ††	no	no	no	yes ††

Key:

yes: Exception test is not required

no: Development should be refused

Notes to table 3:

Some developments may contain different elements of vulnerability, and the highest vulnerability category should be used, unless the development is considered in its component parts.

†    In flood zone 3a essential infrastructure should be designed and constructed to remain operational and safe in times of flood.

††    In flood zone 3b (functional floodplain) essential infrastructure that has passed the exception test, and water-compatible uses, should be designed and constructed to:

• remain operational and safe for users in times of flood;
• result in no net loss of floodplain storage;
• not impede water flows and not increase flood risk elsewhere.

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Footnotes

78. Landfill in this annex is as defined in Schedule 10 of the Environmental Permitting (England and Wales) Regulations 2010. ↩