Flood Risk Assessments are required in all planning applications where the proposed development site is within Flood Zones 2 and 3 as determined by the Environment Agency. But, we often get asked by clients why the local Council/Environment Agency have asked for an Flood Risk Assessment when the planned development is in Flood Zone 1.
Areas classified as Flood Zone 1 are those with less than a 0.1 percent likelihood of flooding. The Flood Risk Assessment is mandatory for sites of 1 hectare or more within Flood Zone 1. Sites less than 1 hectare in Flood Zone 1 also require a Flood Risk Assessment. These sites may have important drainage concerns, and must be notified to the local planning authority through the Environment Agency. Critical Drainage Areas (CDA) are specific areas within Flood Zone 1 where man made drainage infrastructure has been classified as being at risk of failing, which could result in runoff causing problems downstream. Flood Risk Assessments do not have to be just an area where flooding issues could occur.
Flood Zone 1 may also require an Flood Risk Assessment. This is the case if your property might be affected by flooding from other sources (surface reservoirs or water drains) or a shift in the use of your development to a class that is more vulnerable such as residential to commercial.
What if my Site is wholly or partially within a Flood Zone 2 or 3?
A Flood Risk Assessment that is tailored to sites within Flood Zone 1 won’t be suitable for sites that are in Flood Zone 2 or 3. If the Site is in a higher flood risk zone The Council and Environment Agency will demand that data from the flood model from the Environment Agency is included in the Flood Risk Assessment. This is the case even if a part of the Site red line of the planning boundary is within a Flood Zone 2 or 3 or if the development proposed will be located in the lower risk area (Flood Zone 1) of the Site boundary.
How do I find out which Flood Zone my site is located?
If your site is located located in England the site will be located in a flood zone 3 according to the Environment Agency’s Flood map for planning. Find out the Flood Zone your site is situated in by entering your postcode in the Environment Agency Flood Map to find out.
If your site is located in Wales, Natural Resources Wales (NRW) has its individual Flood Zones. Three development advice zones (A B, C and A) are described on their maps, which are linked to various activities in planning. Zones A B, C and A generally are areas of low risk. Zone C is the highest flood outline and is further divided into two zones: C1 and C2.
Zone C1 is described as “areas of the floodplain which are constructed and are served by a significant infrastructure, such as flood defences.
Zone C2 can be described as an “area of floodplain without significant infrastructure for flood defence.”
The Flood Zone C1 and C2 are the same as C3 of the EA Flood Zone 3.
The Scottish Environmental Protection Agency (SEPA), which is located in Scotland assesses flood risk in relation to the risk of flooding caused by surface water, rivers, and coastal flooding. These are divided into high, medium and low risk zones.
Where can I buy a Flood Risk Assessment?
We are able to provide the Flood Risk Assessment, suitable for Sites within a Flood Zone 1. The assessment covers flooding from every source, in a clear report of flood hazards which might be in the area.
