Flood Risk Assessments (FRA) are utilized to evaluate a development proposal in order assess the risk of flooding. The risk does not only come from groundwater sources or rivers (fluvial) however, it is also a result of sources like coastal and estuary sources as well as surface water sources (pluvial).
The Flood Risk Assessment is necessary prior to designing. If the development is located in a Flood Zone, or another at-risk area it is likely that the permit will not be granted without one.
When is an Flood Risk Assessment Required?
In England and Wales, the Environment Agency requires a professional Flood Risk Assessment (FRA) to be included with planning applications in areas believed to be at risk of flooding. If the proposed development falls within 20m of the Environment Agency main stream, you’ll need an assessment of the risk of flooding.
You can use the gov.uk website to find out whether your area is located within a flood zone, or what the flood zone is.
According to the Environment Agency,
For the majority of developments within flood zones, you’ll need to perform an assessment of flood risk.
This includes developments such as:
Flood zone 2 or 3, with minor developments and changes of use.
Flood zone 1: Greater than 1 Hectare (ha).
Flood zone 1 less than one hectare, including any changes in the development type that is a vulnerable class (commercial to residential) and where they could be affected by flooding sources other than sea (surface water drains and reservoirs);
Flood zone 1 is an area that was notified by Environment Agency as having critical drainage problems.
It is also recommended that you consult your local planning authorities to determine if the property is located within an area identified as having critical drainage issues.
What do you make an Flood Risk Assessment Made?
A Flood Risk Assessment is compiled by using data from third-party sources. These can include data taken from the Environment Agency modelling, or independent data collected by consultants. An analysis of the data sets will be undertaken to get a full view of the area and any associated flood related hazards discovered.
What factors influence flooding?
Flooding can be influenced by many factors, such as:
Surface water run-off
Local topography
proximity to rivers and coasts
geology
Groundwater
Current land use
existing drainage
mines
quarries
hardstanding
vegetation cover
rainfall levels
What is Drainage Design/Strategy, and how can it be used?
Flood Risk Assessments usually require you to prove (and prove) that the planned development won’t increase the risk of flooding elsewhere.
In this scenario in this scenario, an Drainage strategy is likely to be demanded by the Local Planning Authority.
They can be found anyplace that isn’t in a floodplain (river, coastal).
It is recommended to ensure that any subsequent run-off due to the proposed development is mitigated.
How can we assist you?
We offer the Level 1 and Level 2 Flood Risk Assessments that:
Determine if flooding is a concern at the development site.
Assess if the area is in danger of flooding.
Identify whether the site may increase the flood risk due to an increase in run-off
Look for sources of flooding.
Evaluate the quality and availability of information.
Assess the flood risk in the location, and assess the impact on flooding in other areas.
Examine the potential scope of appropriate development design and scope additional work where required.
What qualifies us to assist you
Anyone who isn’t a professional or trained in Flood Risk Assessments may produce them. However, the nature of Flood Risk Assessments are complex and require a thorough evaluation. Authorities might reject assessments that do not address all flood scenarios. This could lead to lengthy delays between the approval of plans and the commencement of work.
In the event of a major flooding event, a poor Flood Risk Assessment could even lead to a claim of negligence being made against the developer.