Yes, and the maps do not soften it. The peninsula sits low, flat and close to the sea. About half the postcodes are within 500 metres of the coast. The minimum distance from a postcode here to the waterline is two metres. Whatever flood risk exists for a coastal village in West Sussex, this one carries the full share.
About one in six postcodes sits inside Environment Agency flood zone three, the highest of the standard categories. Another roughly one in twelve sits inside flood zone two. Together that is about a quarter of the area inside a published flood-zone designation before any climate adjustment is applied. The peninsula has the geometry of a flood map: low ground, soft margins, Chichester Harbour pressing in from the north and the open sea sitting along the south.
Surface water is the bigger headline. About one in seven postcodes carries a high surface-water-flood rating. About one in five carries a medium one. Roughly four in ten carry a low one. Stacked together, the majority of postcodes have some surface-water probability on the published register. The drainage problem follows directly from the geography. A peninsula without gradient is a peninsula where rainwater has to wait its turn to leave, and the drains do most of their actual work during the few hours of the year when nobody is watching them.
Once climate allowances are added to the modelling, the picture extends rather than contracts. About four in five postcodes show some elevated future risk in the climate-adjusted scenarios. That is the modelled outlook on current emissions trajectories, not a forecast the maps are willing to swear to, but it is the picture the published maps are working with for the planning horizon out to the middle of the century. It is also the picture the insurance industry is quietly preparing its actuarial tables against.
For insurance, the practical implication is that quotes will arrive with the flood map already loaded into them. Premiums depend on the exact address, the height of the floor above ground, the past claims history at the postcode, and the local flood score the insurer's model spits out. Some quotes will land at standard rates. Others will arrive with elevated premiums or higher flood-specific excesses. A small number will arrive with conditions attached, such as a requirement to evidence flood mitigation already in place at the property. A buyer who skips the flood pages of the conveyancing report is the buyer who finds the real surprise in the post in January.
Below average and not borderline. The maps say what they say, and the maps do not lie about a peninsula with water on three sides and one road out on the fourth.