Yes, for a minority of it, and that minority is larger than the river would lead anyone to expect. The Isle runs through a town whose worst water often has nothing to do with the Isle. Roughly one postcode in five carries a high rating on at least one flood measure. Only a small slice sits inside the formal river zones. The distance between those two facts is the entire answer, and it is the bit estate agent listings never cover.
Start with rivers and the sea, because that is the map most buyers are shown. On the Environment Agency's zone mapping, about 4% of the area's postcodes fall within flood zone 3, the highest-probability band, and about 3% fall within zone 2. Those two are exclusive rather than nested: zone 2 is the additional medium-probability fringe lying beyond zone 3, which is why it can legitimately be the smaller of the two. Between them, they describe a narrow ribbon of the area rather than a general condition.
Surface water is the part the zone maps do not cover, and locally it has form. The Environment Agency's record of historic flooding lists 8 events across the area, the most recent in November 2012, caused by overtopping of defences on an ordinary watercourse. About 1% of the area falls inside those recorded historic extents. An ordinary watercourse is the small stuff, the ditches and streams that nobody photographs until the week they matter, and they sit outside the main river maps entirely.
Looking forward, the picture widens. Once the Environment Agency applies its climate allowance, about 10% of the area's postcodes fall inside the flood zone, against the roughly 4% in zone 3 under present-day assumptions. That is a modelled allowance rather than a forecast of any particular year, but it is the version a mortgage lender in the 2040s will be reading.
For insurance, this is not a place where cover is unobtainable, but it is very much a place where the address matters more than the town. Two houses a few hundred metres apart can produce entirely different quotes and excesses, and the only way to find out which one is being bought is to get an indicative quote before instructing a solicitor rather than after. Anyone relying on the seller's current premium as a guide should remember that policies are priced on the buyer's terms, not the previous owner's.
Across all measures combined, and covering 436 postcodes, about 21% carry a high rating on at least one flood indicator, about 13% a medium and about 36% a low one. That combined indicator folds surface water in alongside rivers and sea, which is why it runs so far ahead of the zone shares. The two sets measure different things and should never be added together or read as the same statement.
Counted as homes rather than postcodes, the Environment Agency's rivers-and-sea mapping puts 247 properties at high risk, 128 at medium and 226 at low, out of 2,235 properties across the 84 postcodes that carry any risk at all. Of the high-risk group, 163 are residential. Postcodes with no modelled risk do not appear in that list, so this is the affected slice of the area rather than the whole of it.
On defences, the modelling offers no comfort. About 4% of postcodes fall inside the high-risk modelled extent with no defence present, and the same share, about 4%, fall inside it with a defence present in the model. Present in the model is a statement about the map, not about safety. It records that something has been built, not that it will hold, and the 2012 event in this area was caused by defences being overtopped.
For coastal context, the nearest tide gauge is at Devonport, where the record from 1962 to 2015 shows a measured rise of about 2.35 millimetres a year. That is a historic measurement over a long record rather than a projection, and for an inland town it belongs in the background of the picture rather than the foreground.
Flooding is the weakest part of the case for living here, and it is weak in the specific way that catches people out: the headline zone figures look modest while the broader indicator says one in five postcodes has a high rating on something. The right response is not to rule the town out. It is to check the exact address on the Environment Agency's own long-term risk tool before falling for the house.