Yes, and not in the technical sense that lets an estate agent shrug it off. Most of the area sits in the highest river and sea flood zone. Every postcode falls inside the zone once the climate allowance is added. The town grew up around a bridge at the mouth of a river on drained marshland, and the water has never forgotten that. This is the one thing here you cannot survey your way out of.
Taking the Environment Agency's river and sea flood zones, about 81% of the area's postcodes sit in flood zone 3, the highest probability band, with a further 5% in flood zone 2. Those two are separate bands rather than one inside the other. Zone 2 is the medium-probability fringe lying beyond zone 3, which is why it is the smaller of the two numbers here: the higher-risk zone has already swallowed most of the map, and there is not much fringe left to be in.
Those zones cover rivers and the sea only. Surface water is not broken out as its own share in that mapping, and on the Somerset Levels it is a live question rather than a footnote, because the land only drains because somebody makes it. About 97% of postcodes here fall under the Axe Brue Internal Drainage Board, which is the administrative form of the sentence "this ground is managed water". Thirty flood events are on record for the area, the most recent in March 2009, caused by the sea overtopping defences.
Add the climate allowance and the picture stops having shades in it. On the Environment Agency's climate-adjusted zone, 100% of the area's postcodes fall inside. Not most. All of them.
For insurance, that matters more than any other line on this page. Flood exposure of this kind shapes what cover costs, what excess is attached to the flood peril and how many insurers will quote at all, and the answer varies address by address rather than town-wide. An indicative quote for the specific property, obtained before you instruct anyone, is worth more than every general reassurance a seller will offer.
Looked at postcode by postcode, and folding surface water in alongside rivers and sea so that a postcode counts if it rates on at least one measure, about 9% of postcodes here rate high, 19% medium and 73% low. Those bands overlap with the zone figures above rather than adding to them; they answer a different question about the same ground.
Counted as homes rather than postcodes, the Environment Agency's rivers and sea mapping puts 45 properties at high risk, 394 at medium and 5,686 at low, out of 9,712 properties across the postcodes that carry any risk at all. Only postcodes with some risk appear in that list, so the total is not the whole housing stock. Of the high-risk properties, 28 are residential.
The uncomfortable detail is what stands between the water and the house. Around 90% of postcodes sit inside a modelled high-risk extent with no defence present in the model, against about 1% inside a defended extent. Defended, in that mapping, means only that a defence exists in the model. It is not a statement that the property behind it is safe.
The coast is close enough to be part of the arithmetic. About 11% of postcodes lie within 500 metres of the shoreline, that being the threshold the data itself uses, with the nearest postcode about 100 metres from the water and the median around 1,600 metres.
Every postcode here falls under a shoreline management plan, and the policy for this frontage is hold the line over the twenty, fifty and hundred year horizons. That is a stated intention to maintain defences on that stretch. It is not a guarantee of funding, and it is not a defence that already exists in front of any particular house.
For the longer view, the nearest tide gauge with a published record is at Devonport, where sea level over the years 1962 to 2015 was measured rising at about 2.35 millimetres a year. That is a measured historic rate over that record rather than a forecast for this coastline.
Flooding is where Highbridge is at its worst, and it is not close. Everything else about the place is a trade-off you can weigh; this is the condition you accept in order to live here at all, and the buyers who go in with a flood report, an insurance quote and open eyes are the ones who stay happy.