FZ2 & FZ3 Specialists • Sequential Test • Exception Test

Flood Zone 2 & 3 Flood Risk Assessments

Expert FRAs for development in high flood risk areas — including Sequential Test, Exception Test and climate change assessment.

FZ2 & FZ3 specialists
Sequential Test support
Exception Test
All LPA areas
17+ years' experience

Development in Flood Zone 2 & 3

Flooding affecting residential properties in a high flood risk area

Developing in Flood Zone 2 or Flood Zone 3 doesn't mean planning permission is impossible — but it does mean your Flood Risk Assessment needs to be technically robust and specifically written to address your LPA and LLFA's requirements.

We prepare Flood Risk Assessments for development in Flood Zone 2 and Flood Zone 3 across all LPA areas in England and Wales. Our reports include Sequential Test evidence and, where required, Exception Test submissions to demonstrate that your development is appropriate for its location and will be safe for its lifetime.

With over 17 years' experience working in high flood risk areas, we understand what LPAs, LLFAs and the Environment Agency require from a Flood Zone 2 or 3 FRA — and we write our reports to address those requirements directly.

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Understanding Flood Zones 2 & 3

Environment Agency Flood Map for Planning showing Flood Zone 2 and Flood Zone 3 classifications
FZ1 — Low Risk
FZ2 — Medium
FZ3a — High
FZ3b

Flood Zone 2 — Medium Probability

A 1 in 100 to 1 in 1,000 annual chance of river flooding, or 1 in 200 to 1 in 1,000 for tidal. Development in FZ2 requires an FRA and a Sequential Test. Most development types are appropriate in FZ2 subject to flood resilience measures.

  • FRA and Sequential Test required
  • Exception Test not normally required
  • Flood resilience measures typically needed
  • Finished floor levels above 1% AEP + climate change

Flood Zone 3a — High Probability

A greater than 1 in 100 annual chance of river flooding or 1 in 200 for tidal. More vulnerable uses (housing, care homes, schools) require both the Sequential Test and Exception Test. Less vulnerable uses require the Sequential Test only.

  • FRA and Sequential Test required for all development
  • Exception Test required for more vulnerable uses
  • Safe access and egress must be demonstrated
  • Flood resilience and resistance measures required

Flood Zone 3b — Functional Floodplain

Land that floods with a 1 in 20 annual chance or is designed to flood. Only water-compatible development and essential infrastructure is appropriate. Residential development is not normally permitted in FZ3b.

  • Very limited development appropriate
  • Water-compatible uses only as a rule
  • Essential infrastructure by exception
  • Sequential and Exception Test both required

What's Included in a Flood Zone 2 or 3 FRA

Our Flood Zone 2 and 3 FRAs are comprehensive, planning-ready reports tailored to your specific site and LPA requirements.

  • Assessment of all flood sources — fluvial, tidal, surface water, groundwater and sewer
  • EA flood map and detailed hydraulic model interrogation
  • 1% AEP (1 in 100) and 0.5% AEP (1 in 200) flood level extraction
  • Climate change assessment to latest EA guidance (RCP8.5 allowances)
  • Sequential Test evidence and structured submission
  • Exception Test submissions (Part 1 and Part 2) where required
  • Finished floor level and threshold recommendations
  • Flood resilience and resistance measures specification
  • Safe access and egress assessment for all return periods
  • Flood warning and evacuation plan guidance
  • Surface water drainage strategy where required by the LPA or LLFA
  • LLFA standing advice compliance confirmation

Frequently Asked Questions

What is the difference between Flood Zone 2 and Flood Zone 3?
Flood Zone 2 (medium probability) has a 1 in 100 to 1 in 1,000 annual chance of river flooding, or 1 in 200 to 1 in 1,000 chance of tidal flooding. Flood Zone 3 (high probability) has a greater than 1 in 100 annual chance of river flooding or greater than 1 in 200 for tidal. Flood Zone 3 is further subdivided into 3a and 3b, with 3b being the highest risk area where most new development is not appropriate.
Can you get planning permission in Flood Zone 3?
Yes, in many cases. Planning permission can be granted for appropriate development in Flood Zone 3 subject to passing the Sequential Test and, where required, the Exception Test. Housing in FZ3a can be permitted if both tests are passed. We have extensive experience securing planning in Flood Zone 3.
How much does a Flood Zone 3 FRA cost?
Flood Risk Assessments for Flood Zone 3 sites typically start from £395+VAT, depending on the complexity of the site and development. Sites requiring Sequential/Exception Test support may cost more. Contact us for a free fixed-fee quote specific to your site.
How long does an FRA for a Flood Zone 3 site take?
Most Flood Zone 3 FRAs are delivered within 3–5 working days of receiving instructions and relevant site information. Complex sites requiring detailed model interrogation or Sequential/Exception Test submissions may take 5–10 working days.
Do I need a Sequential Test for a Flood Zone 2 site?
Yes. Development in Flood Zone 2 requires both a Flood Risk Assessment and a Sequential Test. The Sequential Test demonstrates that no reasonably available alternative sites in Flood Zone 1 exist for the development. An Exception Test is not required for most development in Flood Zone 2.

Trusted by Developers, Architects & Planning Consultants

★★★★★

“Antony was great to work with when we needed a Flood Risk Assessment and Emergency Flood Plan. As an architect I would definitely use FRE Consultants again — professional and produced reports within a good time frame.”

Arkhi Architects
Architect, England
★★★★★

“The service received was great and at a competitive cost. We were granted planning after first submission.”

Holly Addison
Homeowner
★★★★★

“Fast, technically thorough and understood exactly what the LLFA needed. Approved without any queries. Highly recommended for any flood risk or drainage work.”

Planning Consultant
East Midlands

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Flood Risk Environmental

Flood Risk & Environmental Consulting • Independent Flood Risk, Drainage & Utilities Consultants

07826 705389  • 

Leicestershire, England • Covering all of England & Wales

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