Yes, parts of Shoreham carry real flood risk, and about one in six addresses sit in the higher-risk category. The town runs along the mouth of the River Adur and hard against the sea. The estuary and the seafront draw the map between them. Postcodes with a recorded historic flood event come in at under one percent, so the paper trail is thinner than the exposure map. Both those numbers need reading before signing.
On the standard flood-zone map, about one in six Shoreham postcodes sits in Flood Zone Three, which is the high-probability river-and-coastal category. Around three percent sits in Flood Zone Two, which is the medium-probability layer. The rest of the town, moving inland from the estuary and the beach, sits outside both. That is the shape you would expect from an estuary settlement. The risk stacks at the south end and along the river. Higher ground stays dry.
Adding surface-water risk brings roughly one in five postcodes into the medium band and a bit over a third into the low band. Surface-water flooding shows up in a downpour, not a storm surge. It is patchy, it moves with the intensity of the rain, and it is the harder of the two flood types to predict against a specific street. A house that stayed dry through the last three winters is not guaranteed to stay dry through the next hundred-year rain event. The postcode-level detail is the thing to read against any address being seriously considered.
The climate-adjusted flood-zone layer, which models the extra area exposed under a projected scenario, adds zero further Shoreham postcodes to the exposure count. That is not a promise about the future. It reports where the modelled climate scenario draws its extra boundary, and in Shoreham's case it does not extend past what today's higher zone already captures. The local tide-gauge record at Portsmouth still shows sea level trending upward at around two millimetres a year, so the exposure map will be revised. The forward look is: watch the map, not the paperwork.
Insurance follows the map. Any address in the higher zone will need dedicated flood cover, and the premium will reflect both the postcode's position on the current risk map and any recorded history of a claim on the property. Any address outside the zones will price like a standard home, though most lenders will still expect a search to confirm it. The difference between the two premiums is real money, and it is the number that catches out buyers who fell for the view and did not read the postcode. Anyone buying near the estuary or the beach needs a quote in hand before offer, not after.
Below-average on the flood picture, which is the honest verdict. The exposure is concentrated at the south end and along the river, and the addresses beyond it price like ordinary homes. Five minutes on the flood map before offer sorts the two.