Is my home in a flood zone?
Updated 9 October 2026
Two maps answer it: the OPW’s national flood maps, and your council’s flood zones (A, B or C) in its development plan. Put in your address below to check both. Zone A has the highest chance of flooding, Zone C the lowest.
OPW: the Office of Public Works’ CFRAM and national indicative flood maps, shown only as a yes or no within 100 m and 500 m, with a link to the OPW’s own map (its licence doesn’t let us redraw it). Council zones: the development plan’s Flood Zones A and B, under CC BY 4.0. Neither is a verdict on one house; an insurer or an engineer’s site flood risk assessment is.
Flood zones in five facts
- The OPW's flood maps show land that could flood from rivers or the sea in a modelled flood. They are community-scale maps, not a verdict on one house. OPW flood maps (floodinfo.ie)
- Flood Zone A has the highest chance of flooding: more than 1 in 100 a year from a river, or 1 in 200 from the sea. The Planning System and Flood Risk Management Guidelines (2009), §2.23–2.25
- Flood Zone B is moderate, down to 1 in 1,000 a year. Everywhere else is Flood Zone C, the lowest. The Planning System and Flood Risk Management Guidelines (2009), §2.23–2.25
- Flood zones ignore flood defences, because defences can be overtopped or breached. The Planning System and Flood Risk Management Guidelines (2009), §2.23–2.25
- Councils map the zones in their development plans. In Zone A most kinds of new development are inappropriate unless they pass a Justification Test. The Planning System and Flood Risk Management Guidelines (2009), §2.23–2.25
Buying, extending or objecting? The free planning report for the address puts the flood maps beside the planning files, zoning, protected structures and what is planned nearby.
Check an address, then get the free report →The detail
What each zone means
| Zone | Chance of flooding in a year | New development |
|---|---|---|
| A (high) | Over 1 in 100 from a river, over 1 in 200 from the sea | Most kinds are inappropriate unless they pass the Justification Test |
| B (moderate) | 1 in 1,000 up to those levels | Homes need the Justification Test; less vulnerable uses may be fine |
| C (low) | Under 1 in 1,000 | Appropriate from a flood risk point of view |
From The Planning System and Flood Risk Management Guidelines (2009), §2.23–2.25 (Department of Housing, with the OPW), which councils follow when they zone land and decide applications.
Where the answer comes from, and its limits
- OPW flood maps. The Office of Public Works’ CFRAM (community-scale) and national indicative maps of river and coastal flooding. Their licence (CC BY-NC-ND) lets us say whether a mapped extent is within 100 m or 500 m, not redraw it, so we link to the OPW’s own map on floodinfo.ie. We hold these extents for the Dublin area; elsewhere, check floodinfo.ie. The OPW says its maps are not meant to designate individual properties, and places they don’t show can still flood (from drains, groundwater or heavy rain).
- Council flood zones. The Flood Zones A and B in the Strategic Flood Risk Assessment of a development or local area plan, where the council publishes them under CC BY 4.0: today Cork County, Galway County (its towns), Roscommon (its towns), Waterford and Wicklow. Other councils publish maps without an open licence, so we don’t show them yet; their plan’s flood maps are on the council’s website.
- Planning nearby. Applications within 500 m in 5 years, and any in 10 years whose description mentions flooding. Most never do, even where a flood risk assessment was filed, so none is not a clean bill.
- The zones ignore flood defences: a home behind a defence can still be in Zone A. For one house, an insurer’s quote or an engineer’s site-specific flood risk assessment is the real answer.
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