Not the sea. The pavement. Environment Agency river-and-sea zones cover less than one per cent of the postcodes. Surface-water risk touches about a third of postcodes at some level, and about one in eight sits at the high end. Hove drains slower than it looks, which is where the flood story actually lives.
Take the river and sea question first. Environment Agency flood-zone-two coverage sits at about two-tenths of one per cent of postcodes. Flood-zone-three, the highest tier, at about one-tenth of one per cent. That is essentially the seafront edge and nothing behind it. The district has no recorded historic-flood footprint. The problem in Hove is not the Channel arriving with the tide.
Surface water is the actual story. About one in eight postcodes are rated high for surface water. Roughly one in five sit at medium. Around a third at low. Which means the district drains slowly when the rain arrives properly, because Victorian street drainage was not designed for modern downpours. The lower streets fill first. Properties with basements or converted lower floors hear about it before anyone else.
Look ahead. The Environment Agency's climate-adjusted flood zone covers under one per cent of the postcodes, which is up on today's figure but still very small in absolute terms. Sea-level rise at the nearest tide gauge, Portsmouth, has been running at about two millimetres a year across the recorded period. Slow, not fast. Consistent, not dramatic. The long-term Shoreline Management Plan for this stretch of coast is hold-the-line, which is the coastal-management way of saying the authorities intend to keep the sea where it is now, using engineering. That is a policy commitment, not a prediction.
For insurance, the practical consequence is that river-and-sea flood risk is a small conversation, and surface-water risk is a bigger one. Insurers ask both questions on the quote form. A postcode in the high surface-water band tends to face higher premiums, and sometimes a higher excess on the flood portion of the policy. Flood Re, the industry-wide flood-reinsurance backstop, is available for most homes in the district and keeps premiums workable, but it does not cover homes built since 2009. The modern seafront flats built after that date sit outside the scheme, which is worth checking before completion.
Three out of five on the flood scorecard. The sea is not the pressing question. The pavement is. Middling because the surface-water numbers are real, and middling only because the coastal-management framework is holding the sea where it currently sits.