Pirbright's flood risk is middling, and most of it comes from heavy rain, not the river. Fewer than one postcode in a hundred sits in the highest-risk river flood zone. About one in ten is rated high on at least one flood measure. The last recorded flood was a small stream that overflowed more than half a century ago. The risk is small, but it isn't spread evenly, so it depends on which street you buy on.
On the Environment Agency's river-and-sea flood zones, under 1% of Pirbright's postcodes sit in zone 3, the highest-probability band, and about 3% sit in zone 2. Zone 2 is the medium-probability fringe outside zone 3, so the two figures don't overlap. On river and sea flooding alone, most of the village is outside both zones. The agency has four recorded flood events here, the latest in December 1968, when an ordinary watercourse exceeded its channel with no raised defences in place. About 2% of postcodes fall inside historic flood outlines.
Surface water accounts for most of the rest. The postcode ratings below include rainfall runoff alongside rivers and sea, and they flag far more of Pirbright than the river zones do. A house can sit well outside every river zone and still collect water on its driveway in a summer downpour. A seller saying "we've never had a problem" only covers the years they owned the house.
Adjust the Environment Agency's mapping for climate change and about 9% of postcodes fall inside the flood zone. That's a projection of how the zones could widen, not a record of what has happened. A buyer planning to stay twenty years should keep it in mind.
For insurance, most Pirbright homes should not be affected. The few inside the zones, or on a postcode flagged high for surface water, can expect underwriters to ask more questions, and the premium can go up. Get an insurance quote on the exact address before you instruct a solicitor, not afterwards.
At postcode level, taking the worst rating across all measures, surface water included, about 11% of Pirbright's postcodes are rated high on at least one measure, 10% medium and 24% low. These bands overlap with the river zones above and measure something broader, so don't add the two sets of figures together. The high share here comes mainly from surface water.
A count of homes shows the scale better. The Environment Agency's rivers-and-sea mapping lists 540 properties in the 22 Pirbright postcodes that carry any risk at all. Of those, 22 properties are at high risk, 11 of them homes, with 17 at medium risk and 33 at low. Postcodes with no river or sea risk don't appear in the count.
About 1% of postcodes fall inside the high-risk extent with no defences modelled, and another 1% where a defence is present in the model. A defence in the model means some protection is there. It doesn't mean the house is safe, and it doesn't cover water coming off the road.
The nearest tide gauge, at Portsmouth, recorded sea level rising by about 2 millimetres a year across its record from 1962 to 2023. That is a measured historical rate and says little about an inland Surrey village. Pirbright's risk comes from rain and small streams, not the sea.
Pirbright is middling on flood risk. Most homes are clear, but about one postcode in ten is rated high for flooding, mostly from surface water, so check the exact address before you buy.