Bexleyheath has a middling flood risk, and none of it comes from a river or the sea. The official river maps leave the town alone completely. Even with climate change built in, they still do. Rain is the problem, and roughly one postcode in seven is rated high risk on at least one measure. The risk is real, but it lives in the drains and the dips in the road.
None of Bexleyheath's postcodes lie in the Environment Agency's river-and-sea flood zones: 0% in Flood Zone 3, the highest-probability band, and 0% in Flood Zone 2, the medium-probability fringe beyond it. Watling Street has crossed this heath since the Romans built it, and no river on the official maps has been in its way. A listing that says "not in a flood zone" is telling the truth here, but it answers the river question, and nobody was asking about a river.
Surface water is the realistic route in. It comes from heavy rain landing faster than the ground and the drains can take it, and on a built-up former heath it collects in particular streets and low spots, not evenly across the town. The postcode figures below are the measure that picks it up.
The Environment Agency's climate-adjusted flood zones, which model how the river-and-sea zones would grow under future climate change, also cover 0% of Bexleyheath's postcodes. That changes the modelled scenario for rivers and the sea and leaves rainfall exactly where it was.
For insurance, a town with no river or sea flood zone is usually an easier conversation, but insurers price surface-water exposure at the level of the property, and two houses on the same road can come back with different answers. An indicative quote on the specific house, early in the process, tells you more than any town-wide figure.
Taking the postcode-level measures, which count a postcode if it reaches a given level on any one of several flood indicators, surface water included, about 14% of Bexleyheath's postcodes rate high risk on at least one, about 16% medium and about 27% low. The best single check for a buyer is the Environment Agency's long-term flood risk map: enter the exact address and read the surface-water layer separately from the river one.
On the Environment Agency's modelled flood extents, 0% of Bexleyheath's postcodes fall inside the high-risk extent, whether or not a defence is present in the model. So there are no flood defences here to argue about, because the river-and-sea model gives the water nowhere to reach. A defence appearing in that model would only mean a structure exists. It would say nothing about whether a particular house stays dry.
The nearest tide gauge, at Dover, recorded sea level rising by about 2.2 millimetres a year between 1961 and 2010. That is the rate measured at Dover over those years. For a town with no postcode in the sea flood zones, it matters as background more than as a threat to Bexleyheath itself.
The historic flood record shows 0% of Bexleyheath's area inside a recorded flood outline. That is reassuring. It only covers floods someone mapped, though, and a flooded cul-de-sac after a summer cloudburst rarely makes it onto the official record.
Bexleyheath sits in the middle on flood risk: the rivers and the sea leave it alone, and the rain is what decides which streets need a second look.