Yes, in a narrow band of it, and the band is exactly where you would guess. Just under one postcode in ten sits in the highest river-and-sea flood zone. More than half are within a few minutes of the water. The last recorded flood came over the defences rather than around them. This is less a town at risk than a seafront at risk with a town sitting safely uphill of it.
The Environment Agency's mapping puts about 9% of the town's postcodes in flood zone 3, the highest-probability band for flooding from rivers and the sea, with a further 4% in flood zone 2. Zone 2 is the additional medium-probability fringe beyond zone 3 rather than a wider ring containing it, so the smaller number is not a mistake in the arithmetic. In a valley opening directly onto a bay, both bands are describing the same body of water.
Surface water is measured separately and has its own history here. The town flooded repeatedly through the last century, badly as recently as 1990, and a large-scale alleviation scheme completed in 1993 now channels rainwater out through the jetty at the end of it. That scheme then created a second problem by interrupting the drift of sand up the bay, which is why the beach was rebuilt with timber groynes and fresh sand in 2005 and 2006. Under 1% of postcodes fall inside a recorded historic flood outline, and the flood register holds one event for the town, in February 2014, caused by the sea overtopping defences.
Apply the Environment Agency's climate allowance and the share of postcodes inside the flood zones rises to about 15%. That is the forward-looking version of the same map, not a prediction of any particular winter.
For insurance, the town-wide figure is worthless and the address-level one is everything. Two houses four streets apart will get quotes that look like they belong to different counties. Anyone buying near the seafront should get an indicative quote before instructing a solicitor rather than after exchange, because the premium is the market's honest opinion of the risk and it does not care what the brochure said about sea views.
Taking a broader postcode-level view that folds surface water in alongside rivers and the sea, about 14% of postcodes rate high on at least one measure, about 8% medium and about 19% low. Those bands overlap the flood-zone figures rather than stacking on top of them.
Counted as homes rather than postcodes, which is the more useful unit, the Environment Agency's rivers-and-sea mapping lists 1,372 properties across the 66 postcodes that carry any risk at all. Of those, 296 sit at high risk, 46 at medium and 49 at low, with 408 at very low. Of the high-risk properties, 157 are residential. Postcodes with no risk do not appear in that listing, so this is the affected end of town described in detail, not the whole town.
On defences, about 8% of postcodes fall inside a modelled high-risk flood extent with no defence present in the model, against about 6% where one is. Defended means a structure exists in the modelling. It does not mean the house behind it stays dry, and the single recorded event here came over the top of defences that were already there.
The coast is close by any measure. About 53% of postcodes sit within 500 metres of it, a threshold the mapping defines rather than a statement about any individual house, with a median distance of around 450 metres and a closest postcode 9 metres from the water.
Every postcode in the town is covered by a shoreline management plan, and the stated policy across all three horizons, twenty, fifty and a hundred years, is to hold the line and maintain defences roughly where they stand. A policy is an intention published by a coastal authority, not a structure and not a guarantee. Plans get reviewed, funding gets directed elsewhere, and a hundred-year horizon outlives every mortgage anyone reading this will take out.
The nearest long-running tide gauge, at Portsmouth, has recorded a rise of about 2 millimetres a year across its 1962 to 2023 record. That is measured history, not a forecast, and it is the trend the hold-the-line policy is being asked to keep up with.
Flood risk here is middling and unusually legible. It is not a town-wide problem, it is a street-level one, and the streets in question are the ones people move here for.