Low, and the rivers and the sea keep their distance. No postcode sits in a river or sea flood zone. There is no recorded flooding on the map. Heavy rain is the only thing asking questions. The risk here lives on particular streets, not across the town.
The Environment Agency's river-and-sea flood zones take in none of Ashley's postcodes: about 0% sit in zone 3, the high-probability band, and 0% in zone 2, the medium-probability fringe beyond it. The Agency's property-level register of risk from rivers and sea does list five postcodes carrying some risk, covering 8 properties at medium risk, 6 at low and none at high. So the honest reading is no flood zone anywhere, and a handful of individual homes that a buyer should check by address rather than by postcode.
Surface water is the more likely source of trouble. That is rain arriving faster than drains and gardens can take it, and it gathers on low spots and at the bottom of slopes, regardless of whether a river is anywhere nearby. The postcode indicators further down fold it in, which is why they show more than the flood zones do.
Looking ahead, the Environment Agency's climate-adjusted flood zone also takes in about 0% of Ashley's postcodes. On the river-and-sea measure, the projected future looks like the present one.
For insurance, that should mean flood rarely drives the premium on most homes here. The exceptions are the few properties the register singles out, where an insurer's own address-level model may take a different view from the general picture. An indicative quote on the exact address, before the solicitor is instructed, costs nothing and settles it.
At postcode level, counting a postcode if it rates high on at least one flood measure, surface water included, about 3% of Ashley's postcodes are high, about 5% medium and about 20% low. These bands overlap with the flood-zone figures and measure something wider, so they are not added to them. One in five postcodes carrying a low flag is the kind of detail an estate agent's summary rounds down to "no flood risk", and a buyer should not.
On defences, the Environment Agency's modelled high-risk extents take in 0% of postcodes, whether undefended or defended, and the low-risk undefended extent is also 0%. Nothing is standing between the water and the houses in the model because, on rivers and sea, the model has no water heading for them in the first place.
The coast is about three kilometres from the typical postcode and roughly two kilometres at its nearest. The shoreline management plan for the stretch nearest Ashley sets a policy of no active intervention at every horizon: 20, 50 and 100 years. That is a stated intention not to build or maintain defences there, not a promise either way about what the sea does, and at this distance it describes the coastline rather than anyone's back garden.
The nearest tide gauge, at Portsmouth, recorded sea level rising at about 2 millimetres a year over its record from 1962 to 2023. That is a measured historic rate, not a forecast.
The historic flood map records no flooding in the area: about 0% of postcodes fall inside a recorded flood outline. That is reassuring, and it is also only a record of what somebody wrote down. A conversation with the neighbours about the last big storm is still worth having.
Flood risk is one of Ashley's better stories: rivers and sea largely out of the picture, with surface water on a few streets the one detail to check before you sign.