Parts of Poyle are at risk of flooding, and the climate maps expect that share to grow a lot. About one postcode in eight is in the highest-risk river zone. Ten floods are on record. Only a handful of homes rate as high risk. On the map the risk looks large. Count the homes and it is quite small.
The Environment Agency puts about 13% of the area's postcodes in flood zone 3, the river-and-sea zone with the highest chance of flooding. Another 16% are in flood zone 2, the medium-probability fringe beyond it. Zone 2 is a separate band, so those 16% are extra and none of the zone 3 postcodes are counted again inside it. Poyle is on the edge of the Colne Valley, and its lowest ground floods first, as river valleys tend to. The agency has recorded ten floods here. The most recent was in January 2003, when a main river overtopped its channel where there were no raised defences.
The Environment Agency does not give surface water its own figure for Poyle. It turns up only in the postcode measure further down, mixed in with rivers and sea. That matters in a village where tarmac, yards and loading bays cover so much of the ground, because rain on that kind of surface has to drain somewhere.
Once the agency's climate allowance is added, about 47% of the area falls inside the flood zones. That is a modelled picture of how the zone would grow if the climate shifts as projected. It puts no date on any flood, and it is the figure most likely to come up when a house is next sold.
For insurance, the gap between a home on Poyle's higher ground and one on the valley floor can decide whether the premium is routine or needs explaining. Get a buildings insurance quote on the exact address while the conveyancing is still running, because cover is priced on the address and the village average is no help.
Counting postcodes that rate high on at least one flood measure, rivers and sea or surface water, about 8% are high risk, 18% medium and 48% low. That measure overlaps with the zone figures, so the two sets of percentages should never be added together. They are two different ways of measuring the same village.
Counting properties is more reassuring. The Environment Agency's rivers-and-sea mapping lists 821 properties in the 48 postcodes that carry any risk at all. Postcodes with no risk are left out, so the full housing stock is bigger. Of those 821, four are rated high risk, 37 medium, 361 low and 70 very low, and only one of the four high-risk properties is a home. The rest of the high-risk exposure is commercial buildings and empty floor space, which suits a village where the sheds outnumber the semis.
On the agency's modelled flood extents, about 10% of postcodes are in the high-risk area with no defence in the model, against 2% where a defence is present. A defence in the model means a wall or bank was included in the calculation. It does not mean the water stays out. Mostly, though, nothing stands in the way, and anyone describing a Poyle home as "defended" should be asked which wall they mean.
The nearest tide gauge is at Portsmouth, where sea level rose by about 2 millimetres a year between 1962 and 2023. That rate was measured on the south coast, a long way from here. Poyle's water comes down the valley.
Poyle's flood risk is middling. A real share of the land is in the river zones, but very few homes are rated high risk.