Reigate's rivers are not the problem; its rain is. Hardly any of the town sits in a river flood zone. About one postcode in seven carries a high flood risk on at least one measure. The last recorded flood is older than most of the people now buying. A town can be safe from the river and still get wet from the sky, and Reigate is that town.
Start with rivers and the sea. By the Environment Agency's mapping, about 1% of the area's postcodes fall in Flood Zone 2, the medium-probability band, and none fall in Flood Zone 3, the high-probability band. The two zones are separate bands, with Zone 2 the fringe beyond Zone 3, so a small Zone 2 figure and an empty Zone 3 is a coherent result, not a gap in the map. The town is drained by the Wallace Brook and its tributaries, which feed the River Mole, and on this measure they are modest neighbours.
Surface water is where the risk actually lives, and it follows rainfall and ground rather than riverbanks. It is the kind of flooding that arrives when drains and small channels cannot keep up, and it can reach streets nowhere near a river. The Environment Agency holds 10 recorded flood events for the area. The most recent dates from September 1968 and came from an ordinary watercourse whose channel could not carry the water, with no raised defences involved. About 1% of the area falls inside historic flood outlines. That record is short and old, which is useful, and also a reminder that absence of recent floods is not the same as absence of risk.
Looking forward, the Environment Agency's climate-adjusted flood zone covers about 2% of the area. The river-and-sea exposure grows only a little under that allowance, which keeps the forward picture close to the present one on this particular measure.
For insurance, the river-and-sea picture works in a buyer's favour, since insurers look hard at flood zones and most of Reigate sits outside them. Surface-water risk is assessed too, and a property in one of the higher-rated postcodes can still see that reflected in its premium or its terms. Getting an indicative quote for the specific address before committing costs nothing and settles the question faster than any map.
The postcode-level measure is broader and the reason this page does not read as an all-clear. About 15% of the area's postcodes rate high on at least one flood measure, about 16% rate medium, and about 27% rate low. These figures fold surface water in alongside rivers and the sea, and they overlap with the zone figures above rather than adding to them. They are the better guide to whether a given street has ever been flagged for water of any kind, and in Reigate, a fair number have.
Defences barely enter it. The Environment Agency's modelled high-probability flood extent covers well under 1% of postcodes with no defence present, and none where a defence sits in the model. The low-probability undefended extent reaches about 1%. In plain terms, where the modelled water goes, nothing engineered stands in its way, and where a defence does appear in a model elsewhere, that means only that one exists, not that the house behind it is dry.
Sea level is a distant concern for an inland town. The nearest tide gauge is at Portsmouth, where the record from 1962 to 2023 shows the sea rising at about 2mm a year. That is a measured historic rate at the coast, not a forecast, and it bears on Reigate only as background.
Reigate's flood risk is below average for a buyer: the rivers barely register, but the surface-water flags on a sizeable minority of postcodes mean the street matters far more than the town's reputation for keeping its feet dry.