GovWire

This guidance is for planning applicants.

As a planning applicant, you may need to carry out a flood risk assessment (FRA) for your proposed development site.

You will usually need to pay a flood risk specialist to carry out aFRAfor you. An exception to this may be if it is for a simple, low risk development, for example, a house extension. In this case you may be able to do it yourself. If you are not sure,contact the Environment Agencyfor advice.

Yourlocal planning authority (LPA)may refuse yourapplication if you do not include aFRAor if it is not satisfactory.

When you need a flood risk assessment

You need to do aFRAfor all development (includingminor developmentand changes of use) proposed:

• in flood zones 2, 3 or 3b
• within flood zone 1 with a site area of 1 hectare or more
• in areas with critical drainage problems
• within flood zone 1 where the LPAsstrategic flood risk assessment (SFRA)shows it will be at increased risk of flooding during its lifetime
• that increases thevulnerability classificationand may be subject to sources of flooding other than rivers or sea

When you need a sustainable drainage strategy and what to include

You need to include a sustainable drainage strategy if your application is for:

• major developmentwith surface water drainage
• development with surface water drainage in anarea at risk of floodingsuch as flood zones 2 or 3, or at risk of surface water flooding

You should include all the information set out in:

• section 6 of the site-specific flood risk assessment checklist
• What information on sustainable drainage needs to be submitted with a planning application

Your sustainable drainage strategy can be a separate document or be part of aFRA. Check to see if the LPA or lead local flood authority (LLFA) have local policies or guidance with additional requirements.

Research the development site

To access the right flood risk advice for your development, you need to complete all the following steps:

• use theEnvironment Agency Flood Map for Planningto find if the development is in flood zone 1, 2 or 3
• check the LPAs SFRA to identify if the site is in flood zone 3b (functional floodplain).
• find out the vulnerability classification - if you are unsure discuss this with your LPA and make it clear in your FRA
• checkTable 2 of the Planning Practice Guidanceto find out if the proposed vulnerability classification is incompatible with the flood zone
• check the LPAs SFRA to identify if the site is in flood zone 1 now but will be at risk of flooding from rivers or the sea during its lifetime
• check the LPAs SFRA to identify if the site is at risk from any other source of flooding or it will be during its lifetime
• refer toCheck the long term flood risk for an area in Englandto identify if your site is at risk of flooding from surface water, groundwater (where data is available) or reservoirs
• check if the site is in an area with critical drainage problems these are currently only designated in Devon and Cornwall and the Environment Agency has provided local standing advice for these areas
• establish the site area (in hectares) and whether the development ismajor development
• check if your development is a minor extension

A minor extension is a household or non-domestic extension with a floor space of no more than 250 square metres.

In some cases, SFRAs may not hold suitable information for your site on future flood risk or functional floodplain. In such cases, your FRA will need to provide suitable information.

Note that Check the long term flood risk for an area in England also shows the risk of flooding from rivers and sea. However, this information is different to the flood zones shown on the flood map for planning. This means you should not use it for development planning.

Access the right advice

Follow the Environment Agencysadvice for minor extensionsif you are doing aFRAfor a minor extension in flood zone 2, 3 or 3b.

Follow the Environment Agencysstanding advice for vulnerable developmentsif you are doing aFRAfor a development (including change of use) in flood zone 2 classed as:

• more vulnerable- except for landfill or waste facility sites, caravan or camping sites where the Environment Agency should be consulted
• less vulnerable- except for waste treatment, mineral processing, and water and sewage treatment where the Environment Agency should be consulted
• water compatible - including essential accommodation within a water compatible development

You should followstanding advice for vulnerable developmentsfor change of use development in flood zone 3 where the vulnerability classification will:

• be water compatible
• remain unchanged as less vulnerable

Also follow local flood risk standing advice for development (including change of use) if your site is in an area with critical drainage problems these are currently only designated in 