A Flood Risk Assessment (FRA) is a technical evaluation that identifies potential flooding hazards in a specific area and assesses how proposed developments may impact flood risk. It considers various sources of flooding, including rivers, surface water, groundwater, and drainage systems, and analyses factors like flood extent, depth, and velocity. An FRA is required for certain planning applications, especially for sites in higher flood zones or larger developments. Professional FRA services are vital for developers, helping to optimise site layouts, meet regulatory requirements, and reduce costs and delays by addressing flood risks early in the planning process. We've broken this down further below:
What is a Flood Risk Assessment (FRA)?
A Flood Risk Assessment (FRA) is a technical analysis conducted to evaluate the potential flooding hazards in a specific area and assess the impact of proposed developments on flood risk. An effective FRA identifies all potential flooding sources including:
- Rivers and streams (fluvial flooding)
- Surface water runoff (pluvial flooding)
- Groundwater
- Coastal and tidal waters
- Sewers and drainage systems
The assessment evaluates flooding probability by analysing factors such as extent, depth, and velocity, while also considering climate change projections. A comprehensive FRA determines how a proposed development might affect existing flood patterns and recommends appropriate mitigation measures to reduce flood risk both on-site and in surrounding areas.
When is a Flood Risk Assessment Required?
A Flood Risk Assessment is mandatory for planning applications when:
- Your site is located within Flood Zone 2 or 3 (including 3b - functional floodplain)
- Your development site is 1 hectare (10,000m²) or larger in size
- Your site is susceptible to sources of flooding other than rivers or seas
- Your local planning authority's Strategic Flood Risk Assessment (SFRA) indicates the site may face increased flood risk during its lifetime
- It is specifically requested by your local planning authority as part of the planning application process
Recent Updates to Flood Risk Mapping
In January 2024, the Environment Agency published updated long-term flood risk maps with significant changes to their coverage and accuracy. The official 'Flood Map for Planning' is scheduled for an update in March 2024. These revisions now include smaller watercourses that were previously unmapped, potentially affecting many more development sites than before.
It's important to note that local planning authorities will assess planning applications based on the most current mapping available, which may differ from what was available when initial site assessments were conducted.
Why Professional FRA Services Matter
Engaging experienced flood risk consultants delivers substantial value to development projects of all sizes. For developers specifically, professional FRA services:
- Identify optimal site layout opportunities to maximize developable area while minimising flood risk
- Reduce costly design changes and project delays by addressing flood risk issues early in the planning process
- Support value engineering by recommending cost-effective mitigation measures tailored to your specific development needs
- Strengthen planning applications with robust technical evidence that satisfies regulatory requirements
- Mitigate potential liability issues by demonstrating due diligence in addressing flood risk
- Enhance marketability of completed developments through improved resilience and reduced insurance premiums
Key Takeaway
Whether you're planning a small residential extension or a major development, understanding your site's flood risk profile is essential. The changing climate and evolving regulatory landscape make professional flood risk assessments more valuable than ever for developers, homeowners, and businesses alike.