Pagham is partly in the present flood zone and almost entirely in the future one. About one in 13 postcodes sits in the highest-risk river or sea flood zone today. Surface-water exposure adds another one in 20 at medium-or-worse. The climate-adjusted flood envelope covers about 19 in 20 of the village. Today's risk is contained. Tomorrow's risk is almost everywhere.
The river and sea flood zones tell a quieter story than the village's geography suggests. About one in 100 postcodes sits in flood zone two, the medium-probability layer. About one in 13 sits in flood zone three, the high-probability layer where river or sea flooding has a meaningful annual chance of occurring. That high-zone exposure clusters where you would expect it, near Pagham Harbour and along the lowest-lying stretches of the coast. The streets a few minutes inland sit on slightly higher ground and largely fall outside both zones. Recorded historic flooding from the Environment Agency dataset for the village reads zero, which is the kind of fact that gets read two ways. Either the defences have done their job, or the village has been lucky, or both.
Surface-water flooding, the kind that comes from rainfall pooling rather than from rivers or the sea, runs a slightly broader pattern. About one in 20 postcodes carries medium-or-worse surface-water exposure. About one in four carries low-or-worse, which is a wide net that catches almost any drainage-prone street, sunken corner, or low patch. The high-exposure share is small, around one in 100. Surface water is the flood category that often surprises people, because it does not respect coastline or river. It follows topography, drains, and the assumptions made by whoever last resurfaced the road.
The climate-adjusted future flood envelope is where the picture changes. Roughly 19 in 20 postcodes fall inside the climate-scenario flood zone, the layer that models sea-level rise and higher rainfall intensity over the planning horizon. That is not a forecast of imminent inundation. It is the model's view of what the flood envelope is projected to look like once climate change is baked into the assumptions. Coastal villages on flat ground tend to score this way. The formal management policy for this stretch of coast is to maintain rather than retreat, and that holds across the 20-year, 50-year and 100-year planning horizons. Whether the policy still holds across the longest of those horizons is a different question from whether it is current today.
Insurance reflects the picture. Properties in the flood-zone-three layer, or with documented surface-water exposure, generally pay more for buildings cover, sometimes considerably more. Flood Re, the industry pool that backs flood cover for older domestic properties, applies to most of the residential stock here. Flood Re does not cover homes built since 2009, which on this village's housing-age profile is a small share but not zero. Anyone buying near the harbour, near the coast, or on the lowest-lying streets should ask the seller for the most recent insurance renewal quote and the address-level flood risk report. The postcode-level number and the address-level number are not the same thing.
For flooding, Pagham scores about average. Not because the village is uniformly safe, and not because it is uniformly at risk, but because both of those statements are true at the same time, depending on which street you stand on. The careful buyer checks the specific address before exchanging. The careless buyer reads the headline number and gets a surprise on the first big-tide storm.