Mostly no, but a river starts here and runs straight through the middle. About one in fifty postcodes sit in the river flood zones. More carry some risk once rain on the roads is counted. No past flood is recorded in the area. The risk is low for the village and specific for a handful of streets.
On the Environment Agency's river-and-sea flood maps, about 1% of Overton's postcodes fall in Flood Zone 3, the highest-probability band, and about 2% fall in Flood Zone 2. The two zones do not overlap: Zone 2 is the medium-probability fringe beyond Zone 3, so the smaller Zone 3 figure is not part of the larger one. Here the source of that risk is the River Test, which rises at Ashe and flows west through the village. A chalk stream looks harmless in August, which is exactly when most people book viewings.
Surface water, the flooding that comes from heavy rain overwhelming drains rather than a river bursting its banks, has no separate figure for the area. It is folded into the postcode-level indicators further down, and that is where it shows up. Plenty of homes nowhere near the Test sit on that list, which is the part a seller is least likely to volunteer.
Looking forward, the Environment Agency's climate-adjusted mapping puts about 4% of postcodes inside the flood zones once future rainfall and river flows are allowed for. That is a projection built into the modelling, not a date on the calendar, but it is the figure a mortgage lender will be thinking about for the full length of a 25-year loan.
For insurance, the handful of homes in or near the flood zones are the ones likely to see higher premiums, excesses on flood claims, or questions from insurers before cover is offered. For the rest of the village, flood should not be the thing that moves the quote. Get an indicative quote for the exact address before paying for a survey, not after.
At postcode level, taking the worst reading across every measure including surface water, about 6% of Overton's postcodes are rated high on at least one measure, 7% medium and 18% low. These bands overlap with the flood-zone figures above and use a different method, so they should not be added together or treated as the same thing. The honest reading is that roughly one postcode in five carries some kind of flag, and most of those flags are low.
Counting homes rather than postcodes is more useful. The Environment Agency's rivers-and-sea mapping lists 103 properties in the five Overton postcodes that carry any risk at all. Of those, 8 are at high risk, all of them homes, 1 is at medium risk and 22 are at low risk. Postcodes with no river or sea risk do not appear in that count, so it describes the exposed corner of the village, not the whole of it.
On whether anything stands between the water and the house, about 1% of postcodes sit in the high-risk extent with no defence in the model, and about 1% sit in it with a defence present. A defence being present in the model means something has been built; it does not mean the property behind it will stay dry. The word "defended" in a listing is a description of engineering, not a promise.
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 historic rate, not a forecast, and for an inland chalk-stream village it matters far less than what the Test and the drains do in a wet winter.
The brief records no historic flooding in the area. That is reassuring, and it is the absence of recorded events rather than proof that water has never come up; a quiet record in a village this size can also mean nobody wrote it down.
Overton's flood risk is middling rather than alarming: low for most of the village, but real for the small group of homes near the river and the surface-water hotspots. Check the exact address, not the village.