Polegate floods from the sky, not the sea. Barely any postcodes sit in the river or sea flood zones. One in five carries some level of high surface-water flood risk. The climate scenario pushes about one postcode in fourteen into a mapped flood zone by mid-century. The rain is the story, not the river.
The river and sea flood zones cover almost nothing here. About one postcode in a hundred falls inside the medium-probability flood zone, and only around three in a thousand sit inside the high-probability zone. Historical flooding has touched under one percent of postcodes on record. That is unsurprising when you look at where the town is: on a ridge in the gap between the Weald to the north and the South Downs to the south, with the Pevensey Levels, the drained former bay, sitting off to the east. The rivers do not really come through Polegate. They come around it, mostly onto farmland.
Surface water is a different conversation. About one postcode in five has some level of high surface-water flood risk. Roughly one in seven carries medium risk, and closer to three in ten carries low. Surface water is the water that comes off pavements, roads, roofs, and gardens when the drains cannot cope with the intensity of a downpour, and it is entirely a function of local topography, drainage capacity, and the direction of the rain when it arrives. Around eight percent of postcodes sit inside the Pevensey and Cuckmere Internal Drainage Board area, meaning there is active drainage infrastructure managed by a statutory body for that share of the town. That helps, but it does not eliminate risk further up the network.
Under climate-change scenarios, the flood-zone share rises from about one percent today to around seven. That is a seven-fold jump, and it puts one postcode in fourteen into a mapped flood zone by the mid-century horizons the Environment Agency now uses for planning decisions. For a buyer expecting to own the house for twenty or thirty years, that is the more relevant number than today's zone map. Whether it is a number to worry about depends on which postcode, and the granularity here is postcode-level, not town-level.
For insurance, the practical consequence is that a postcode carrying high surface-water risk may attract higher premiums, larger excesses on the flood section of a buildings policy, or in the worst case difficulty getting standard cover at all. A postcode outside all the mapped zones sees ordinary premiums. There is no way to answer the insurance question for the town as a whole, because underwriting works at the postcode level and often at the individual property level. Check the specific address with a broker or an insurer before you exchange.
Below average for flood risk at two out of five, and it is the surface-water problem doing the work rather than the river or the sea. Polegate is not a town where floodwater comes up the road from a river. It is a town where floodwater comes down the road from a cloudburst, and any given postcode can be well outside that risk or well inside it. Check yours.