Yes, more than its river maps suggest. Only a small slice of the village falls in the river flood zones. Once rain running off the ground is counted, the risk spreads to a much larger share of postcodes. The Environment Agency's model shows no change to the high-risk area when defences are included. Flood risk is Chalgrove's weakest point, and you need to check it house by house.
On the Environment Agency's river-and-sea flood map, about 4% of Chalgrove's postcodes fall in Flood Zone 3, the highest-probability zone. Another 4% fall in Flood Zone 2, the medium-probability band just outside it. The two zones don't overlap, so together they cover a small part of the village. "Not in a flood zone" will be true of most houses here, and it is the line a sales brochure is most likely to quote and least likely to explain.
Surface water, from heavy rain that can't drain away, is the risk the river zones leave out. This page has no separate surface-water figure for Chalgrove. It is included in the postcode ratings further down, and it is the main reason those ratings are higher than the zone shares.
The Environment Agency also models how the zones could grow as the climate changes, and on that measure about 31% of Chalgrove's postcodes are inside the flood zone. It is a modelled scenario that adds an allowance for heavier rainfall. It tells you the risk is expected to cover more of the village than it does today.
For insurance, the result depends on the exact house. A home in or near the mapped zones may cost more to insure or carry a higher excess, while one on higher ground nearby may notice no difference. Get an insurance quote for the exact address early, before paying for searches and surveys. The insurer's answer is the one that will affect what you pay each year.
Taking each postcode's worst rating across several measures, surface water included, about 18% of Chalgrove's postcodes rate high on at least one measure. Another 18% rate medium and about 31% rate low. The measures overlap with the river zones, so this is a different figure from the zone shares, not one to add to them.
The Environment Agency's rivers-and-sea mapping lists 432 properties across the 17 Chalgrove postcodes that carry some risk. Postcodes with no risk are left out entirely. Of those properties, 44 are rated high risk, of which 31 are homes. Another 14 are rated medium and 59 low. Counting houses makes it clearer than postcode shares: most of the village is unaffected, and a few dozen households carry most of the risk.
On defences, about 31% of postcodes fall within the high-probability flood extent without defences, and the figure is still about 31% with defences included. "Defended" only means the model includes a flood defence, not that a house is safe. In Chalgrove's case, including the defences doesn't change the result at all.
The nearest tide gauge is at Portsmouth, where sea level rose by about 2 millimetres a year between 1962 and 2023. That is a measured past rate on the south coast. For an inland village in South Oxfordshire, the sea is the one flood source that barely applies.
No flooding is on record within the village. That is reassuring, but a lack of recorded floods only means none was written down. It doesn't mean none has ever happened, and it says nothing about the modelled risk.
Flood risk is Chalgrove's biggest weakness. It affects only a small part of the village, but if you buy one of the affected houses, you carry that risk every year.