Conwy Flood Risk
Conwy has a Low flood risk from rivers and the sea , with 2.8% of homes in a Medium or High band.
Conwy has 15,138 residents and 6,903 homes. Ranked 170 of 621 in Wales for rivers and sea flood risk.
Why Are Parts Of Conwy In Flood Zone 3 But Rated Low Risk?
14.2% of postcodes in Conwy fall in Flood Zone 3, but the flood risk band for rivers and the sea is low. The two maps measure different things: the Flood Zone ignores defences, and the band counts them.
When Has Conwy Flooded Before?
The Environment Agency holds 10 recorded flood outlines covering Conwy, the most recent dated 26 December 2015.
Absence of a record is not evidence that a place has never flooded — the Environment Agency states that a lack of coverage does not mean an area has never flooded.
What Does Conwy's Flood Risk Classification Mean?
14.2% of postcodes in Conwy sit in Flood Zone 3, the planning band for land with a 1% or greater annual chance of river flooding or 0.5% or greater of sea flooding — and the map that draws it deliberately ignores flood defences.
The flood risk band for rivers and the sea is Low , with 2.8% 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.
Conwy is one of the places where they disagree most in England: a large share of its postcodes are in Flood Zone 3, yet few of its homes carry a Medium or High band. The gap is the defences — land the planning map must treat as floodplain, behind a barrier that lowers the present-day chance of flooding.
Which Postcode Districts Cover Conwy?
Each district below is one postcode district that falls inside Conwy. 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, and the district pages linked from the checker are keyed to the town that holds most of its postcodes.
| Postcode district | Postcodes here | Rivers and sea band | Surface water addresses |
|---|---|---|---|
| LL31 | 250 | Low | not published for this district |
| LL32 | 138 | Low | not published for this district |
| LL30 | 35 | 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.