Metropolitan Lisburn Flood Risk

Rivers and the sea Very low less than a 0.1% chance in any year

Surface water Not mapped No open surface water source exists for Northern Ireland

Groundwater Not mapped No open groundwater source exists for Northern Ireland

Reservoirs Not mapped Reservoir flood maps are not published openly for Northern Ireland

Metropolitan Lisburn has a Very low flood risk from rivers and the sea , with 0.5% of homes in a Medium or High band.

Metropolitan Lisburn has 31,186 residents and 1 homes. Ranked 91 of 527 in Northern Ireland for rivers and sea flood risk.

Read this before relying on these figures. Northern Ireland's own flood maps are not published under an open licence, so the band above is modelled, not DfI's official mapping. The model is undefended — it does not account for flood defences, so a defended town can read as more exposed than DfI's own map shows — and it covers rivers only. For a property-level answer, use Flood Maps NI.

What Does Metropolitan Lisburn's Flood Risk Classification Mean?

The flood risk band for rivers and the sea is Very low , with 0.5% of homes in a Medium or High band. Unlike the Flood Zone, the band counts the defences that are actually in place, which is why the two can describe the same street differently and both be right.

Flood Zone versus flood risk band: the full comparison · What the Flood Zones mean

Which Postcode Districts Cover Metropolitan Lisburn?

Each district below is one postcode district that falls inside Metropolitan Lisburn. The band is the one shared by most of that district's postcodes, so it describes the district rather than a single street — enter a full postcode in the checker for one address. A district can cover more than one town: every district here overlaps another place, so the checker may name a neighbouring town for some of these postcodes.

Postcode districts covering Metropolitan Lisburn, with the flood risk band shared by most of each district's postcodes. A district can span more than one local area, so its band is a summary and not a property-level answer.
Postcode district	Postcodes here	Rivers and sea band	Surface water addresses
BT17	488	Not mapped — no rivers-and-sea band covers this district	not published for this district
BT10	15	Not mapped — no rivers-and-sea band covers this district	not published for this district
BT27	1	Not mapped — no rivers-and-sea band covers this district	not published for this district

"Not mapped" is not "no risk". It means no rivers-and-sea band covers that district in the source — surface water can still flood it, and both Camden and Islington flooded from surface water in July 2021 while carrying no mapped rivers-and-sea band.

What Else Is Near Metropolitan Lisburn?

Flood risk in Northern Ireland How this nation classifies flood risk, and its gaps
What each flood risk level means The annual chance behind each band word