Tollesbury has some flood risk, concentrated in a small part of the village. Fewer than one in ten postcodes are in the highest-risk flood zone. A few dozen properties are rated at high risk from rivers or the sea. No past flooding is on record. The village is on the estuary, so being close to the water and being exposed to it go together.
On the Environment Agency's river-and-sea mapping, about 8% of Tollesbury's postcodes are in Flood Zone 3, the band with the highest chance of flooding, and none are in Flood Zone 2. Zone 2 is the medium-risk fringe outside Zone 3, so a nil figure there means the risk edge is sharp: a postcode here is either in the highest band or outside both.
No separate surface-water figure is published for the village. Surface water is counted within the postcode indicators further down, alongside rivers and the sea.
With the Environment Agency's allowance for climate change added, the share of postcodes in the flood zone stays at about 8%. On current modelling, the risk is not expected to spread into new parts of the village.
For insurance, a home in that highest-risk band is likely to be quoted differently from one a few streets inland, and some insurers may load the premium or set conditions. Get an indicative quote for the exact property early, while you are still deciding which house to buy, because the answer can vary between neighbouring homes.
A broader postcode measure takes a postcode's worst result across several types of flooding, surface water included. On that measure, about 7% of postcodes rate high risk on at least one of them, 16% medium and 34% low. A postcode only needs to fail one test to count, so these shares run higher than the river-and-sea zone figures.
The Environment Agency also counts individual properties for rivers and the sea, and it only lists postcodes that carry some risk. Seven postcodes in Tollesbury make the list, covering 248 properties. Of those, 47 are rated high risk, 34 medium, 47 low and 2 very low. Of the 47 at high risk, 14 are homes. This count is more useful than the postcode shares, because a buyer cares about properties at risk, and on this count the number is small.
About 8% of postcodes fall inside the Environment Agency's high-risk flood extent when defences are left out of the model, and about 3% when defences are included. In the modelling, "defended" means a defence exists. It does not tell you how high it is, what condition it is in, or whether it will hold in a given storm. An agent who describes a house as "defended" is using the modelling term without any of that information.
The nearest postcode is about 20 metres from the coast, and the median is about 600 metres. About 28% of postcodes are within 500 metres of the coast, a fixed cut-off applied in the same way across the whole area. In Tollesbury, whether a house is near the water is a matter of degree.
The shoreline management plan for this coast is to hold the line: keep the existing defences where they are, for the next 20 years, the next 50 and the next 100. That is what the authorities intend to do. The money has not been committed, and the policy says nothing about the condition of any defence today. The pier was destroyed in the Second World War to keep invaders off the estuary, and the shoreline has been the government's job ever since, with the same mix of good intentions and funding rounds.
No historic flooding is recorded in the area. That is reassuring as far as it goes, but it only covers floods that someone recorded, and a coastal village built this close to the water has had plenty of tides.
Flood risk here is middling. Most of Tollesbury is outside the flood zones, but a few dozen properties near the water are exposed, and the defences in front of them rely on funding that has not yet been promised.