Most of Merley is not at flood risk, and the part that is, is specific. Almost nothing here falls inside the river-and-sea flood zones. Once surface water is counted, about one postcode in twelve rates high on at least one measure. Three flood events sit on the record. So the honest answer is a postcode question rather than a Merley question, and the two get confused constantly.
On the Environment Agency's river-and-sea mapping, about 1% of the area's postcodes sit inside flood zone 3, the highest-probability band, and none falls inside flood zone 2. Those two are exclusive bands rather than nested ones: zone 2 is the additional medium-probability fringe lying beyond zone 3, so a smaller zone 2 than zone 3 is not a contradiction, it means the fringe is narrow. For rivers and the sea, the estate is almost entirely off the map.
Surface water runs on a different indicator, and it is where the local risk actually lives. Rain arriving faster than the drains can take it has no interest in flood zones, which is why the postcode ratings sit higher than the zone shares. About 1% of the area falls inside recorded historic flood outlines, and three flood events are on the record, the most recent in January 2014, when a main river exceeded its channel capacity with no raised defences in place.
Adding the climate allowance barely moves anything. About 1% of postcodes fall inside the climate-adjusted zone, the same share as present-day zone 3, so the modelled river-and-sea footprint does not widen across the estate.
For insurance, that combination is mostly unremarkable and occasionally not. Most addresses here will price as ordinary risk and nobody will ask a second question. The ones inside the zone, or carrying a surface-water rating, will get the follow-up questions, and a quote can change across a single postcode boundary. Getting an indicative quote before instructing a solicitor is cheaper than finding out after exchange.
Across the area's postcodes, about 8% rate high on at least one flood measure, 9% medium and 25% low, with surface water folded in alongside rivers and sea. Those bands overlap the zone figures rather than adding to them: the same postcode can appear in both, and often does. What they describe is one postcode's rating, not the condition of the estate.
Counted as properties rather than postcodes, only those carrying some risk appear in the Environment Agency's rivers-and-sea mapping at all: 12 postcodes here, holding 341 properties between them. Within that group, 6 properties are rated high, 23 medium and 17 low, and 2 of the high-rated ones are residential. Two homes is a small number until one of them is the one under offer.
On the modelled extents, about 1% of postcodes sit inside a high-probability extent where a defence is present in the model, and about 1% inside a high-probability extent with no defence modelled at all. Present in the model means the map knows a structure exists. It does not mean the structure is maintained, adequate, or standing between a particular house and the water on the day it counts.
The shoreline management policy covering these postcodes is hold the line across all three horizons, at 20, 50 and 100 years. Hold the line is a stated intention to maintain defences on that frontage rather than a guarantee, and it is not evidence that a defence already exists. Merley is inland of the argument in any case: the nearest postcode sits about 3.8 kilometres from the coast, the typical one about 5.8, and none is within 500 metres of it.
At the nearest tide gauge, at Portsmouth, sea level has been recorded rising about 2 millimetres a year across a record running from 1962 to 2023. That is a measured historic rate over six decades, not a projection, and it comes from a gauge well along the coast rather than from anything in Dorset.
Flooding is the middling entry on Merley's card: not a reason to walk away from the place, not something to wave off either, and the answer changes entirely depending on which postcode the offer letter has on it.