The Flood Risk Assessment is required for all planning applications when the proposed development site falls located within Flood Zones 2 and 3 according to the Environment Agency. Many clients ask us what the reason is behind why Flood Zone 1 is required by the Local Council/Environment Agency.
Flood Zone 1 is an area that has less than 0.1 percent chance of flooding. Flood Zone 1 sites with at least 1 hectare must have an Flood Risk Assessment. Sites smaller than one hectare within Flood Zone 1 also require an Flood Risk Assessment. These sites are those with significant drainage problems, and are required to be reported to the local authority responsible for planning through the Environment Agency. CDAs are the areas within Flood Zone 1 that have been recognized by the Environment Agency as being susceptible to flooding. This could lead to the runoff of water from downstream. Flood Risk Assessments don’t just deal with issues with flooding.
Flood Zone 1 may also require the completion of a Flood Risk Assessment. This is the case if your property may be affected by flooding caused by other sources (surface reservoirs or water drains) or a shift in the use of your development to a class that is more vulnerable like commercial to residential.
What will happen if my property is within the Flood Zone 2?
An Flood Risk Assessment that is specifically designed for sites in Flood Zone 1 won’t be suitable for sites in Flood Zone 2 or 3. Flood model data from the Environment Agency and Council will be required in the event that the Site is situated in an area that is more hazardous to flood. Even if a part of the Site redline boundary is in Flood Zone 2 or 3, or if the proposed development is within the flood zone that is lower (Flood Zone 1), this will be the case.
How do I find out which Flood Zone my site is in?
Your site will fall into Flood Zone 1 to 3 If it is located in England. The Flood Zone was established by the Environment Agency Flood map. To determine the which Flood Zone is your site is located, just type in your postcode on the Flood Map by Environment Agency.
Natural Resources Wales (NRW) is a separate Flood Zones when your site is situated in Wales. The maps depict three zones of development advice (A-B C, A and C) that could be linked to various plans. Zones A B, C and A are typically areas with moderate risk. Zone C represents the most extreme flood line and is subdivided further into C1 and C2.
Zone C1 is an area of floodplains that have been created and is served by important infrastructure, like flood defences.
Zone C2 can be described as an “area of floodplain that is not surrounded by 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) is situated in Scotland is a flood risk assessment agency that rates by the probability of flooding caused by surface water, rivers, as well as coastal flooding. The zones are classified as high, medium, and low-risk zones.
Where can I purchase an Flood Risk Assessment?
The Flood Risk Assessment is available for all sites in the Flood Zone 1. The assessment will cover flooding from all sources as well as an assessment of any flood dangers that could be present.
