Short answer: To check if a house in Ireland is in a flood zone, open the OPW flood maps on floodinfo.ie, search the address, and turn on the river and coastal flood extent layers and the past flood events layer. Inside a 1 in 100 year (river) or 1 in 200 year (coastal) extent, or near a recorded event, expect the insurer to exclude flood or decline, and get a quote before sale agreed. The maps cover about 300 communities; outside them, no zone means unmapped, not safe.
Two different things get called a flood zone in Ireland, and buyers mix them up. One is the OPW flood map: a modelled line showing where water would reach in a flood of a given size. The other is the OPW register of past floods: dots on a map for events that actually happened, with a date and a note. Insurers read both. So should you.
The maps
The CFRAM programme modelled about 300 communities. For each it drew three river extents (1 in 10, 1 in 100 and 1 in 1000 year) and three coastal ones (1 in 10, 1 in 200 and 1 in 1000). A 1 in 100 year flood has a 1% chance in any year. Over a 30 year mortgage, that is roughly a 1 in 4 chance of seeing it once. The maps are on floodinfo.ie and they are free.
What the maps do not do: they say nothing about towns outside the 300 studied, they do not cover surface water after a cloudburst, and they carry a warning that they are not meant to designate individual properties. That last point is why a bank will still lend inside a zone. The insurer is the problem.
The past events register
This is the part most buyers never open. Every reported flood since the 1980s, some older, each with a location, a source (river, coastal, groundwater) and often a note from the OPW or a local engineer. Our sample house in Clonakilty sits in a modelled 1 in 10 year extent, and the register lists eleven events within 500 m, one of them at the spot in 2009. A seller does not have to volunteer that. The register does.
What insurers do
Irish insurers use address-level flood models fed by the OPW data plus their own claims. Inside an extent or near a recorded event, expect one of three outcomes: standard cover, cover with flood excluded, or a decline. A flood exclusion is not the end of the world, but the bank needs buildings cover that includes flood, so a decline stops the mortgage. Get a quote before you go sale agreed, not after.
Checking one house
Open floodinfo.ie, search the address, turn on the river and coastal layers and the past events layer. Look at the plot, then at the street behind it. Ask the seller in writing whether the house or garden has flooded and whether a claim was made, and ask for the current insurance schedule. If you want it done for you, the free snapshot on this site flags flood for one Eircode, and the full report lists every recorded event within 500 m with the OPW notes.
By area: flood records for every county and 200 towns.
Questions people ask
- Will a bank lend on a house in a flood zone?
- Usually yes, if you can get buildings insurance that includes flood cover, because the mortgage requires it. A decline from every insurer stops the loan. Get the quote before you bid, not after the survey.
- Does a flood relief scheme change the answer?
- It can. Where the OPW has completed a scheme, the protected area is mapped as a benefitting area with a standard of protection (usually 1 in 100). Insurers under the Insurance Ireland and OPW arrangement are meant to take completed schemes into account, though demountable defences are treated more cautiously. Ask the insurer directly.
- Is a 1 in 1000 year zone a problem?
- Rarely for insurance. It marks the extreme-event extent and most insurers ignore it. It is worth knowing for a basement or ground-floor flat.