Flood Risk Assessment in Laois
Expert flood risk assessments for planning applications throughout County Laois. From Barrow corridor sites in Portarlington to Triogue River developments in Portlaoise, 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 Laois?
Yes, if your site is in or near Flood Zone A or B, or Laois County Council has requested flood risk information at Further Information stage. The Laois County Development Plan 2021–2027 sets out flood risk management policies FRM 1 to FRM 14, supported by the County Laois Strategic Flood Risk Assessment, applying the 2009 Planning System and Flood Risk Management Guidelines. In Laois that usually means the Barrow (Portarlington), the Owenass (Mountmellick), the Triogue (Portlaoise) and the upper Nore and Erkina catchments.
Flood Risk Assessment for Laois Planning Applications
If you're submitting a planning application to Laois 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 Laois County Development Plan 2021-2027 and the Planning System and Flood Risk Management Guidelines.
Laois sits at the head of two of Ireland's major river catchments — the Barrow and the Nore — and has well-documented fluvial flood risk. The River Barrow affects Portarlington, where significant flood events have occurred, while the Owenass River caused severe flooding in Mountmellick in November 2017. The Triogue River flows through Portlaoise, creating flood zones through the county town, and the Erkina River affects Rathdowney and Durrow. The upper Nore and its tributaries add risk around Mountrath, Castletown, and Borris-in-Ossory.
- River Barrow corridor sites in Portarlington
- Owenass River flooding in Mountmellick
- Triogue River sites through Portlaoise
- Erkina River flooding (Rathdowney, Durrow)
- Upper Nore and tributary flooding (Mountrath, Castletown)
What's Included
Every FRA we complete for Laois 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 Where data is limited or outdated, we undertake bespoke hydraulic modelling (1D/2D HEC-RAS).
Multi-Catchment Analysis
Assessment for sites affected by multiple river systems with appropriate hydraulic analysis.
FFL Comparison
Your proposed finished floor levels compared against design flood levels plus freeboard.
Development Plan Compliance
Explicit demonstration of compliance with Laois County Development Plan flood risk policies.
Further Information Requests
Received an FI request from Laois County Council asking for flood risk information? We regularly handle urgent FI responses for Laois sites. Typical turnaround is 7–10 working days — often faster for straightforward sites.
Key Documents for Laois Flood Risk Assessments
Every FRA we prepare for a Laois 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:
Laois County Council
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)
- Civil Defence – Laois flooding, Mountmellick (November 2017)
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.
Laois Flood Risk Assessment FAQs
What happened in the Mountmellick flood?
On 22 November 2017, the Owenass River burst its banks in Mountmellick after heavy overnight rain, with water from the Slieve Bloom Mountains contributing. A flood relief scheme for the Owenass and its tributaries was lodged for planning with An Coimisiún Pleanála in October 2025, designed to protect over 160 properties.
What are Laois County Council's flood policies?
Chapter 10 of the Laois County Development Plan 2021–2027 contains flood risk management policies FRM 1 to FRM 14 and surface water drainage policies SWD 1 to SWD 8. Your FRA should demonstrate compliance with these, the County Laois SFRA and the 2009 Guidelines.
Which flood data is used for Laois sites?
Design flood levels from OPW CFRAM and NIFM mapping on floodinfo.ie, checked against the SFRA flood zone mapping (including the Portarlington and Mountmellick maps). For unmodelled streams, we carry out hydraulic modelling.
Can I get planning permission in Flood Zone A in Laois?
Possibly. Under the 2009 Guidelines, highly vulnerable development such as housing in Flood Zone A must pass the Development Management Justification Test, and Laois 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 Laois?
Typically 7–10 working days from instruction for a Stage 2 assessment, and often faster for straightforward sites. If Laois 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 Laois Site?
Send us your site address and we'll provide a fixed-price quote, typically within 24 hours.
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