Mostly safe, with edges that matter. About one in fifty postcodes sits in flood zone three. About one in two hundred sits in flood zone two. No postcode has a recorded historic flood. The coast is twenty-five metres from the nearest postcode at its closest point. Aldwick is not on the front line of British flood risk, but the front line is still close enough to read the tide table.
On river and sea flooding, the Environment Agency's higher-risk band covers about one in fifty postcodes in Aldwick. The middle band covers about one in two hundred. The headline is that ninety-eight in a hundred postcodes sit outside any of the higher-risk bands. The footnote is that the two in a hundred that fall inside them are mostly along the coast and the harbour edge, which is also the side of the village with the views and the highest sale prices.
On surface-water flooding, the picture is a little wider. About one in a hundred postcodes is rated high risk, about one in fifty medium, and around one in four touch some low-risk layer somewhere along their edge. Surface water is what happens when a heavy downpour hits the ground faster than the drains can move it. It tracks the village's gradient and drainage rather than its distance to the coast, which is why the surface-water map and the sea-flood map do not look the same.
On forward-looking risk, the Environment Agency's climate-adjusted projection covers about two in three postcodes in Aldwick. That is a much bigger number than today's flood zones because it assumes higher sea levels and more frequent storm surges over the coming decades. The nearest tide gauge, at Portsmouth, has recorded sea level rising at about two millimetres a year across six decades of measurement, which is the curve the projection bakes in. The official coastal management policy for this stretch over the next twenty, fifty, and hundred years is to hold the line, which is the technical way of saying the coast as it stands will be defended rather than abandoned. That is reassuring for owners and a long-term commitment for whichever public body is still funding sea defences a hundred years from now. The climate-adjusted band is not a forecast that two in three homes will flood. It is the area the agency considers exposed under future scenarios and the area new development is expected to plan around.
For insurance, the practical effect is that the two in a hundred postcodes in the higher-risk band will pay more for buildings cover than the rest of the village, and the conversation with an insurer will take longer. The other ninety-eight in a hundred sit outside the higher-risk band and will not see a postcode-driven premium increase on the standard cover. Anyone buying near the seafront or close to Pagham Harbour should ask for the flood-risk report on the specific address before exchanging, because the postcode-level picture and the address-level picture are not always the same thing.
Aldwick rates four out of five on flood risk, which is what a place looks like when the bulk of its homes are inland enough to be safe and the rest are close enough to know the tide table. Buy inland and the risk is small. Buy on the front and the risk is something you live with, manage, and pay for.