Yes, partly, and the partly is the point. Roughly five percent of the village sits in the highest river flood zone. Another small slice sits in the medium zone above that. About a quarter of postcodes carry some surface-water exposure. And the climate-adjusted projection lifts the at-risk share into something closer to one in twelve. None of that makes Rowland's Castle a flood town. All of it makes flood risk a per-property question, not a village-wide one.
For river and sea flooding, the picture splits cleanly. Around five percent of the area sits in the higher-tier flood zone, the one the Environment Agency labels as the highest river-flood risk band. A further roughly two percent sits in the next tier down. The bulk of the village, well over nine in ten, sits outside both. That is what you would expect from a settlement on the southern edge of the South Downs chalk with the Neogene deposits of the Hampshire Basin to the south of it. Coast is not the issue here. Rowland's Castle is several miles inland and the nearest coastline is at the wrong end of a different drainage basin.
On surface-water flooding, which is the kind that does not need a river to misbehave, the picture is more spread out. Around a quarter of postcodes in the village carry some level of high surface-water risk, with roughly one in nine carrying medium and another quarter carrying low. Surface water is the flood category that tends to surprise buyers, because it does not show up on the river-zone maps and it does not respect the obvious low-ground geography. It tracks the way water actually runs across the village after a heavy rainfall event, which is a function of road camber, drain capacity and back-garden levels rather than river proximity. The fact that a quarter of postcodes carry some high surface-water exposure is not catastrophic, but it is the part of the picture worth asking the seller about.
Looking forward, the climate-adjusted projection lifts the share of the area in the higher flood-zone band to about eight percent. That is the figure the Environment Agency publishes for the territory the higher zone is expected to cover under projected climate change, and it is the number any thirty-year mortgage decision wants to be working from rather than the present-day five percent. The direction of travel is the right one to be aware of, and the lower-lying ground in the village is where the additional exposure lands rather than being spread evenly.
For insurance, the practical implication is that this is a postcode where the survey and the flood-risk certificate matter. Most homes here will get standard buildings cover at standard rates, because most homes here sit outside the higher zones. The ones that do sit inside them, or on a postcode flagged for surface-water risk, will face a different conversation with insurers, particularly for new mortgages where the lender will want the flood certificate before completing. Flood Re, the cross-industry scheme that backstops cover for higher-risk homes, does not cover homes built since 1 January 2009, so anyone buying a newer-build in a flagged postcode needs to check what the market will quote without that backstop in play.
Verdict: below average, two out of five, and the rating reflects that the surface-water exposure is broader than the river-zone numbers suggest. This is not a village to walk away from on flood grounds, but it is a village to buy in with the per-property check done properly. The picture is good for most addresses and meaningful for some, and which one of those you are depends on the postcode and the survey, not the village.