Flood Risk Assessment in Mayo
Expert flood risk assessments for planning applications throughout County Mayo. From Ballina on the River Moy to coastal developments around Clew Bay and Westport, we've completed FRAs for residential, commercial, and agricultural sites across the county.
Get a Quote or call 087 417 3832 or WhatsAppIf we can’t answer, please leave a message or send a WhatsApp — we’ll get back to you.Do I need a Flood Risk Assessment for planning in Mayo?
Yes, if your site is in or near Flood Zone A or B, or Mayo County Council has requested flood risk information at Further Information stage. The Mayo County Development Plan 2022–2028 includes Objective INO 19, which is “to ensure that a flood risk assessment is carried out for any development proposal where a flood risk is identified”. In Mayo that most often means the River Moy and Deel catchments, town rivers in Castlebar and Westport, lake levels on Lough Conn and Lough Mask, and Atlantic coastal flooding.
Flood Risk Assessment for Mayo Planning Applications
If you're submitting a planning application to Mayo County Council and your site is in or near a flood zone, you'll need a Flood Risk Assessment that satisfies the requirements of the Mayo County Development Plan 2022-2028 and the Planning System and Flood Risk Management Guidelines.
Mayo has diverse flood risk from both fluvial and coastal sources. The River Moy system flows through Ballina with well-documented flood zones. Castlebar, Westport, and other towns have their own river flooding issues. The extensive Atlantic coastline from Killala Bay to Clew Bay and down to Louisburgh creates significant coastal flood risk, while Lough Conn and Lough Mask affect lakeside developments.
- River Moy corridor (Ballina and environs)
- Castlebar town flood zones
- Coastal sites on Clew Bay and Westport area
- Lough Conn and Lough Mask shoreline developments
- Atlantic coastal properties (Louisburgh, Belmullet, Killala)
What's Included
Every FRA we complete for Mayo sites includes:
Stage 1, 2 & 3 Assessments
Proper methodology using OPW flood mapping and modelling data. Where data is limited or outdated, we undertake bespoke hydraulic modelling (1D/2D HEC-RAS).
Coastal Analysis
For Atlantic coast sites: national coastal flood modelling data with appropriate climate change and storm surge allowances.
FFL Comparison
Your proposed finished floor levels compared against design flood levels plus freeboard.
Development Plan Compliance
Explicit demonstration of compliance with Mayo County Development Plan flood risk policies.
Further Information Requests
Received an FI request from Mayo County Council asking for flood risk information? We regularly handle urgent FI responses for Mayo sites. Typical turnaround is 7–10 working days — often faster for straightforward sites.
Key Documents for Mayo Flood Risk Assessments
Every FRA we prepare for a Mayo site is assessed against the development plan and Strategic Flood Risk Assessment (SFRA) of the relevant planning authority, the national flood risk guidelines, and the latest OPW flood data:
Mayo County Council
- Mayo County Development Plan 2022–2028 (as varied)
- County Mayo Strategic Flood Risk Assessment (August 2022)
National guidance and flood data
- The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG & OPW, November 2009)
- The Planning System and Flood Risk Management – Technical Appendices (November 2009)
- Circular PL 2/2014 – Flooding Guidelines (revised Section 5.28 on minor development)
- OPW Flood Maps – floodinfo.ie (CFRAM, NIFM and NCFHM flood mapping)
- Geological Survey Ireland – GWFlood groundwater flood maps (historic and predictive)
- OPW / gov.ie – Crossmolina Flood Relief Scheme
Links open the official source documents. Development plans are periodically varied, so we always check the current version and any variation SFRA when preparing your report.
Mayo Flood Risk Assessment FAQs
What is Mayo County Council's flood risk policy?
Objective INO 19 of the Mayo County Development Plan 2022–2028 requires a flood risk assessment for any development proposal where a flood risk is identified, and the plan's Strategic Flood Risk Assessment sets out the flood zone mapping the council uses. Your FRA should demonstrate compliance with both, as well as the 2009 Guidelines.
Has Crossmolina flooded, and is there a scheme?
Crossmolina flooded in 1989, 2006 and twice in 2015, with around 120 properties inundated in December 2015. The Crossmolina Flood Relief Scheme on the River Deel was confirmed in September 2024 to protect 116 properties. Sites in and around the town still need an FRA that reflects the current level of protection and any residual risk.
Are coastal sites in Mayo assessed differently?
Yes. For Clew Bay, Killala Bay and the Atlantic coast we use the OPW National Coastal Flood Hazard Mapping, applying climate change and storm surge allowances to the 0.5% AEP tidal level, and consider wave overtopping where the site is exposed.
Can I get planning permission in Flood Zone A in Mayo?
Possibly. Under the 2009 Guidelines, highly vulnerable development such as housing in Flood Zone A must pass the Development Management Justification Test, and Mayo County Council will expect a site-specific FRA to show the development, its occupants and its access are safe without increasing flood risk elsewhere. Minor development such as small extensions, small-scale infill and changes of use is treated differently under Circular PL 2/2014: the Justification Test does not apply, but a commensurate flood risk assessment is still required.
How long does a Flood Risk Assessment take in Mayo?
Typically 7–10 working days from instruction for a Stage 2 assessment, and often faster for straightforward sites. If Mayo County Council has issued a Further Information request with a deadline, tell us when you get in touch and we will prioritise it. Stage 3 assessments with hydraulic modelling take longer and are scoped per site.
Need an FRA for a Mayo Site?
Send us your site address and we'll provide a fixed-price quote, typically within 24 hours.
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