Yes, and the rivers are the smaller part of it. Only a sliver of Catford is in the highest river flood zone. Rain is the bigger problem. About a quarter of postcodes carry a high risk on at least one flood measure once surface water is included. Climate projections roughly double the area inside the river flood zones.
On the Environment Agency's river-and-sea flood maps, about 11% of Catford's postcodes fall in flood zone 2 and about 1% in flood zone 3. The two are separate bands. Zone 3 is the highest-probability ground next to the water, and zone 2 is the medium-probability fringe outside it, which is why the fringe can cover more postcodes than the core. The Ravensbourne and the Pool both run through the district, and unlike many of London's rivers the Pool still runs in the open for most of its length. It's pleasant to walk beside and easy to watch when it rises.
Surface water is a different problem from the rivers, and the zones above don't measure it. It's rain that falls faster than the drains can take it, and in a district built mostly before 1930 on the slopes down to two rivers, it collects in low roads and dips that are nowhere near either river.
The Environment Agency's climate-adjusted mapping puts about 21% of postcodes inside the flood zones once future rainfall and river flows are allowed for. That's the agency's planning allowance for the decades ahead, and it covers about twice the area of today's two zones together.
On insurance, a home in the river zones or on a surface-water route can still be insured, but expect more questions, higher premiums and sometimes a large flood excess. Get an indicative buildings quote on the exact address early, while pulling out costs nothing. The quote reflects the insurer's mapping, which isn't always the same as the seller's view of the house.
Count every flood measure together, surface water included, and about 23% of Catford's postcodes rate high on at least one of them, about 28% medium and about 50% low. A postcode only needs one high reading to count as high, so this is a broader net than the river zones.
Counting properties is more useful than counting postcodes. In the Environment Agency's rivers-and-sea assessment, 52 Catford postcodes carry some level of river risk, covering 1,726 properties. Of those, 34 are at high risk, 245 at medium risk, 514 at low risk and 8 at very low risk, and 26 of the high-risk ones are homes. Postcodes with no river risk don't appear in that count at all, which is why the total is far smaller than the district.
On the defences, about 2% of postcodes fall inside the high-probability flood extent without defences modelled, and the share is still about 2% with them modelled. In other words, the defences in the Environment Agency's model don't take a single postcode out of the high-risk extent here. The agency has 98 recorded flood events in the area, the most recent in September 1968, when the main river overflowed its channel without any raised defences to hold it.
The nearest tide gauge in the national record is at Portsmouth. It measured sea level rising about 2 millimetres a year between 1962 and 2023. That's a long way from inland south-east London, and it has little to do with what happens to the Ravensbourne after a heavy storm.
Flood risk is a weak point for Catford. The river exposure is small and well mapped, but the surface-water risk is spread widely enough that a buyer here should look up every address individually.