Winchcombe has a moderate flood risk, and almost none of it comes from the river. Hardly any homes fall in the river flood zones. About one postcode in five rates high on at least one flood measure once rain run-off is counted. The river has overflowed before. The danger here is water running off the hills, more than water coming up from the river.
The Environment Agency's river-and-sea flood zones barely touch the town. About 5% of Winchcombe's postcodes fall in Flood Zone 2, the medium-probability band, and none fall in Flood Zone 3, the highest. The two zones don't overlap, so the 5% is the whole of the mapped river-and-sea exposure.
Surface water is a different matter, and the zones leave it out. Those flood zones only map rivers and the sea, and say nothing about rain that runs off the Cotswold slopes and into the streets. The town's own name comes from the Old English for a corner valley, which is about as clear a warning about where water collects as a place name gives.
The Environment Agency's climate-adjusted mapping puts about 5% of postcodes inside its future flood zone, the same share as today. On the river measure, a warmer climate doesn't move the line here much.
Insurers price the specific address, and they draw on surface-water mapping as well as the river zones. A clean river-zone result for a Winchcombe house doesn't guarantee a cheap quote if that street catches the run-off. Get an indicative quote on the exact address while the conveyancing is still early, because the price is set by the run-off map as well as the river one.
Count every flood measure together, surface water included, and the picture changes. About 20% of the area's postcodes rate high on at least one measure, 17% rate medium, and 38% rate low. Those shares overlap with the river zones above, so the two sets of numbers cannot be added together. The high share is the one to take seriously.
Counted as properties, the Environment Agency's river-and-sea risk mapping lists 126 properties across the six Winchcombe postcodes that carry any river risk at all. One of those properties is at high risk, three at medium and 11 at low. None of the high-risk properties is residential. Postcodes with no river risk don't appear in that list, which is why the count is small.
The Environment Agency's model shows none of Winchcombe's postcodes inside a high-probability flood extent, with or without defences, and about 2% inside the low-probability extent with no defences modelled. A defence in the model means a structure exists. It says nothing about whether a particular house stays dry. Records list 12 flood events, the most recent in July 2007, when a main river burst its banks because the channel was too small and no raised defences stood in the way. That 2007 note is the clearest evidence on file that nothing stands between this river and the houses.
The nearest tide gauge is at Portsmouth, where sea level rose by about 2 millimetres a year between 1962 and 2023. That is the rate measured on the south coast, and it has no bearing on a Cotswold valley town beyond setting the national context.
Winchcombe's flood risk is below average. The rivers are mostly behaving, but the hills send their water downhill fast, and buyers need to check the street before they get attached to the house.