Hardly at all from rivers, but rain is a different question. Almost none of Oxted sits in a river flood zone. About one postcode in five carries a high flag on at least one flood measure. The worst of it is water with nowhere to drain, not a river bursting its banks. Check the street, not the town.
Start with rivers and the sea. In the Environment Agency's river-and-sea flood zones, about 2% of Oxted's postcodes fall in Zone 2 and none in Zone 3. Zone 3 is the higher-probability band and Zone 2 is the medium-probability fringe beyond it. The two don't overlap, and here the higher-risk band is empty. Much of the area drains into the headwaters of the River Eden, a tributary of the Medway. That's a stream at this end, not an estuary. The Environment Agency's register holds 4 recorded flood events. The most recent was in 1968, when an ordinary watercourse ran out of channel capacity with no raised defences in the way.
Surface water is where the real risk lives. When heavy rain falls faster than the ground and the drains can take it, water collects in dips, low roads and the bottoms of gardens, whatever the river is doing. The river-and-sea zones don't measure this at all. That's why a town can look nearly clear on the river map and still carry flood warnings street by street. Listing photos are always taken on a dry day.
The Environment Agency's climate-adjusted flood zone, which allows for heavier future rainfall and higher river flows, still covers about 2% of Oxted's postcodes. On the river side, the forward look is no worse than the present.
For insurance, the fine print matters more than the town's name. A home outside the river zones but on a surface-water flag can still draw questions, exclusions or a higher premium from an insurer. Get a quote on the exact address before the offer goes in. The seller's claims history is worth asking about directly.
At postcode level, folding surface water in with rivers and sea, about 19% of Oxted's postcodes rate high on at least one measure. About 21% rate medium on at least one and about 37% rate low on at least one. Those bands overlap with each other and with the zone figures above. They count postcodes touched by any measure, so they can't be added together or read as flood-zone shares.
Counting homes rather than postcodes, the Environment Agency's rivers-and-sea risk mapping lists 13 Oxted postcodes carrying some risk, with 340 properties in them. Of those properties, 20 are at high risk, 39 at medium and 19 at low. Of the high-risk properties, 12 are homes. Postcodes with no river or sea risk don't appear in that list at all. So those counts describe the exposed corners, not the town as a whole.
On defences, none of Oxted's postcodes fall inside the high-probability modelled flood extent, whether defences are counted in the model or left out. The question of what stands between the river and the house barely comes up here. Where water does threaten, it arrives from the sky, and defence walls don't deal with that.
The nearest tide gauge is at Portsmouth, which recorded sea levels rising by about 2 millimetres a year across its 1962 to 2023 record. That's a measured historic rate at a coast a long way from Oxted, not a forecast for the town. Nobody in Oxted is buying a house with a sea view.
Flood risk is Oxted's weak spot. River risk is modest, but enough streets carry a surface-water flag that every buyer should check the exact postcode before the survey, not after it.