Yes, and more than its hilltop centre suggests. About a fifth of the town falls in the highest river-and-sea flood zone. A third of postcodes rate high on at least one flood measure. Hundreds of properties carry high risk from rivers and the sea. The name Maldon means "monument hill", and the hill was the sensible part of the plan.
On the Environment Agency's river-and-sea mapping, about 19% of Maldon's postcodes fall in Flood Zone 3, the high-probability band, and another 2% in Flood Zone 2, the medium-probability fringe beyond it. The two bands do not overlap, so the small Zone 2 figure is a thin margin around a much larger core. Maldon's flood map has very little shading in between. Land is mostly either in it or clear of it.
Surface water, the rain that floods streets before any river is involved, has no standalone figure for Maldon in the Environment Agency's published mapping used here. It is folded into the postcode measure further down, which is the one place on this page where it is counted.
Looking ahead, about 12% of postcodes fall inside the Environment Agency's climate-adjusted flood extent, its modelled view of where the zones reach under a changing climate. That is a projection of how the map might grow, and it puts no date on anything.
Insurance follows the map. Homes inside the high-risk zones can expect closer questions from insurers, higher premiums or excesses, and in some cases fewer insurers willing to quote at all. The practical step for a house anywhere near the estuary is an insurance quote on the exact address while the price is still up for discussion, since the premium is part of what the house costs to own.
Counting every measure together, rivers, sea and surface water, about 35% of Maldon's postcodes rate high on at least one of them, 35% rate medium on at least one, and 56% rate low on at least one. A postcode can appear in more than one of those groups, because each counts any measure that reaches that level.
The Environment Agency's rivers-and-sea mapping counts properties as well as postcodes. Across the 141 postcodes in Maldon that carry some risk, and only those appear at all, 4,182 properties are listed: 444 at high risk, 314 at medium, 1,103 at low and 1,242 at very low. Of the 444 at high risk, 265 are homes.
Defences change the picture less than buyers hope. About 17% of postcodes fall within the Environment Agency's high-risk extent with no defences counted, and about 12% within it once defences in the model are allowed for. "Defended" means a defence is present in the model. Somewhere in that model a line marks a wall or bank, and the model does not say how tall it is.
The water is close. About 36% of postcodes are within 500 metres of the coast, the threshold the Environment Agency's coastal measure uses for the whole area, the typical postcode is about 690 metres away, and the nearest is 14 metres from the tidal edge. At 14 metres, a postcode is part of the estuary's furniture.
The shoreline management plan for this stretch of the Blackwater sets a policy of holding the line, meaning keeping defences where they are, for the next 20, 50 and 100 years. A policy is a stated intention for each of those horizons. The money to carry it out has not been committed, and the plan says nothing about what defences stand today. The plan is written a century ahead, and the money behind it is agreed one spending round at a time.
Flood is Maldon's weakest point. It is the issue that should shape where in town a buyer looks, more than any other.