Flood Risk Assessments & Drainage Strategies in Cardiff
Independent flood risk consultants serving Cardiff and surrounding areas. Planning-ready FRAs and SuDS drainage strategies from £295, delivered within 3–5 working days.
Flood Risk Assessments in Cardiff
Cardiff planning applications require a Flood Consequence Assessment (FCA) under TAN15 (2024) rather than a standard English FRA. We prepare FCAs for all Welsh LPA areas. Learn more about TAN15 FCAs →
Flood Risk Environmental provides Flood Risk Assessments, SuDS drainage strategies and detailed drainage design for planning applications across Cardiff and the wider South Wales region.
Cardiff has significant flood risk from the River Taff and the Severn Estuary, with extensive areas of the city in high flood risk DAM zones under TAN15 (2024). Cardiff Council and Natural Resources Wales (NRW) are the key consultees for flood risk in Cardiff. Planning applications in Cardiff's flood risk areas require a Flood Consequence Assessment (FCA) under TAN15 (2024) rather than a standard English FRA.
Our reports are prepared by a qualified consultant with over 17 years' experience and written specifically to satisfy the requirements of Cardiff Council and Natural Resources Wales (NRW) as the statutory consultee for flood risk in Wales.
Services in Cardiff
- Flood Risk Assessments — from £295
- SuDS drainage strategies for planning
- Detailed SuDS and drainage design
- LLFA SuDS proforma completion (Cardiff Council / SAB)
- Sequential and Exception Test submissions
- S23 Ordinary Watercourse Consent
- EA Flood Risk Activity Permit applications
- LLFA drainage objection responses
Flood risk in Cardiff
Cardiff sits where the Taff, Ely and Rhymney meet the Severn Estuary, which carries a very large tidal range. The Cardiff Bay Barrage impounds the Taff and Ely to form the freshwater bay, but tidal flood risk from the estuary remains the defining issue for much of the waterfront and city centre, alongside fluvial risk along the three rivers.
Crucially, flood risk in Wales is assessed differently from England. Development is judged against Planning Policy Wales and TAN15, and the assessment is a Flood Consequence Assessment (FCA) rather than an FRA, using Natural Resources Wales (NRW) flood mapping rather than the Environment Agency's. We prepare Flood Consequence Assessments to the Welsh standard for Cardiff sites.
Cardiff Council is the Lead Local Flood Authority. We deliver TAN15-compliant Flood Consequence Assessments and SuDS drainage strategies (SuDS approval — SAB — applies in Wales) for Cardiff development.
Local flood facts — Cardiff
- Main watercourses: River Taff, River Ely and River Rhymney
- Lead Local Flood Authority: Cardiff Council
- Main flood sources: Tidal, fluvial and surface water
- Key FRA consideration: Severn Estuary tidal risk, the Cardiff Bay Barrage, and Welsh policy (TAN15)
When Do You Need a Flood Risk Assessment in Cardiff?
Planning applications in Cardiff require a Flood Consequence Assessment (FCA) under TAN15 or Flood Risk Assessment in the following circumstances:
Development in Flood Zone 2 or 3
Any development in London's Flood Zone 2 or 3 areas requires an FRA. The LLFA will object to applications in flood risk areas without a robust FRA and drainage strategy.
Major Applications (10+ dwellings)
Major planning applications in Cardiff — 10 or more dwellings, sites over 0.5ha, or non-residential floorspace over 1,000m² — require an FRA in any flood zone.
Sites Over 1 Hectare in FZ1
Large sites in Flood Zone 1 may require an FRA if over 1 hectare, to demonstrate that drainage is adequate and runoff won't increase downstream flood risk.
LLFA Drainage Conditions
Where Cardiff Council has imposed a pre-commencement drainage condition, we prepare the detailed SuDS design package needed to satisfy the condition and secure approval.
LLFA Drainage Objections
If your Cardiff planning application has received a flood risk or drainage objection from the LLFA, we can review it and prepare a technical response to resolve it fast.
Change of Use
Converting commercial buildings to residential use in a flood risk area in Cardiff typically requires a new Flood Risk Assessment to confirm future occupiers will be safe.
Frequently Asked Questions
Trusted by Developers, Architects & Planning Consultants
★★★★★ 5.0 from 6 Google reviews
“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… his report went a good way in helping us get planning permission on a tricky site. Highly recommended.”
“Antony carried out my Flood Risk Assessment and has done a great job. My architect commented that the report was professionally drafted and very easy to follow. I highly recommend Antony's services.”
“Antony carried out a SuDS report for one of our projects and provided an excellent service throughout — quick to respond, clear communication, and a thorough, detailed report within the agreed timescale. We will certainly be using his services on all future projects!”
“Extremely helpful, prompt and friendly service carrying out a Flood Risk Assessment for a home project that required planning permission in a flood risk area… the price was reasonable and given up-front, and the final report was highly professional and exactly as required.”
“I had an extension completed on my house and needed a Flood Risk Assessment for planning. The service received was great and at a competitive cost. We were granted planning after first submission.”
“Nice and quick service. Recommend A++”
Need a Flood Risk Assessment in Cardiff?
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