Flood Risk Assessment
When is this required:
All planning applications for:
- development within, in whole or in part of flood zone 2 and/or flood zone 3;
- development on sites with an area of 1 hectare or more (in flood zones 1, 2 or 3); and
- development within critical drainage areas.
What information is required?
For residential and non-residential development of less than 250 square metres in flood risk zones 2 and 3, a simple flood risk assessment, which includes a plan showing finished floor levels and estimated flood levels, will be required. For other qualifying developments, a Flood Risk Assessment should identify and assess the risks of all forms of flooding to and from the development and demonstrate how these flood risks will be managed, taking climate change into account.
Guidance provided by the Environment Agency and Defra outlines the scope of Flood Risk Assessments based on the location of the development, the links below provide guidance for each scenario:
- 'Flood Zone 1 and Critical Drainage Areas’
- 'Flood Zones 2 and 3’
- 'Flood Zones 2 and 3: minor extensions and vulnerable development’
Overall, it is expected Flood Risk Assessment will contain:
- reference to the Strategic Flood Risk Assessment (often adopted as part of the Local Plan);
- a sequential/exception test if necessary;
- plans, including outline of development proposals with identified SuDS;
- assessments of flood risk and surface water run-off, including impacts to offsite locations; and
- flood management and protection measures.
The 'Site-specific flood risk assessment: Checklist' contained on the Planning Practice Guidance website may help preparation.