Whitton's flood risk is middling, and very little of it comes from the rivers. Only a sliver of postcodes are in a river flood zone. None are in the highest one. About one in ten rate high once rain running off the streets is counted. The water to worry about here falls on Whitton, it doesn't flow into it.
The Environment Agency's river-and-sea mapping puts about 3% of Whitton's postcodes in flood zone 2 and none in flood zone 3. Zone 3 is the highest-probability band, and zone 2 is the medium-probability fringe beyond it, so the 3% is the whole of Whitton's river exposure on this measure. The River Crane and the Duke of Northumberland's River both run along the old boundaries. Neither puts a single postcode into the top band.
Surface water is a different story, and it's left out of those zones. Whitton is noticeably flat, laid on gravel with patches of brick clay. When a downpour arrives faster than the drains can take it, the water collects on roads and in gardens instead of draining away. That's what drives the higher readings further down this page, and it's the risk most likely to reach a living room here.
Looking ahead, the Environment Agency's climate-adjusted mapping still puts about 3% of postcodes in the zone, the same as today's figure. On the modelled river picture, the extra rain expected from climate change doesn't add any postcodes.
For most homes, insurance should be straightforward, since river exposure is small. The homes that need more thought are the ones on a high surface-water rating, where an insurer can ask more questions or quote higher. Ask the seller whether there has ever been a flood claim on the house, and get a quote on the exact address while the conveyancing is still running. Insurers price a claim history very differently from an average.
Counting surface water alongside rivers and sea, about 10% of postcodes rate high on at least one measure, about 16% medium and about 45% low. A postcode only has to trip one indicator to make a band, so these figures overlap with the zone shares above and shouldn't be added to them. On this wider measure the postcodes rating high outnumber those in the river zones, which shows where the risk lies.
The more useful number is homes. The Environment Agency's rivers-and-sea mapping lists 1,098 properties in the postcodes that carry any risk at all, and only those postcodes appear. Of those, 12 are at high risk, 16 at medium and 486 at low. Eleven of the twelve high-risk properties are homes.
On the Environment Agency's modelled flood extents, none of Whitton's postcodes are in the high-probability extent, defended or undefended, and about 4% are in the low-probability undefended extent. "Defended" on that model means a defence appears in the modelling, which says nothing about whether it would hold. In Whitton the question barely comes up, because the high-probability extent is empty either way.
The nearest tide gauge with a long record is at Portsmouth, where sea level rose by about 2 millimetres a year between 1962 and 2023. Whitton is a long way inland and well above sea level, so that figure goes in the file marked context.
No historic flooding is recorded for any part of Whitton in the Environment Agency's records. That's good news, and it's also only as complete as the records are.
Whitton's flood picture is middling, with almost no river risk and some surface-water risk. Most buyers will never have to think about it. The ones who do will be on one of a handful of flat streets after one very wet afternoon.