Bicknacre does have a flood risk, and most of it comes from rain running off the land. The river-and-sea flood zones hardly touch the village. Even so, about a fifth of postcodes rate high on at least one flood measure. Only a handful of individual homes carry a high river risk. When the water comes here, it usually comes off the fields and down the road.
On the Environment Agency's river-and-sea flood zones, about 1% of postcodes in the Bicknacre area are in Flood Zone 3, the highest-probability band. None are in Flood Zone 2, the medium-probability fringe outside it. The only recorded flood in the area was in February 1947, when a main river overflowed its channel. There were no raised banks to hold it back.
The wider postcode indicators tell a different story, and the difference comes from sources other than rivers and the sea, mainly surface water. Rain on clay farmland and on the 1969 and 1980s estates has to go somewhere. Water is never far away either: the average home is about 270 metres from a pond, stream or ditch. Bicknacre has no big river that floods every winter. Its risk is spread across a lot of small low points.
With the Environment Agency's allowance for climate change added, the share of postcodes in the flood zones rises to about 1%. The river risk stays low on that projection, even though it hasn't gone away.
Insurance depends on which measure the insurer reads. A home that is outside the river zones but on a surface-water flow path can still get a higher premium or an excess, and insurers price each address, not the village as a whole. Ask for an indicative insurance quote on the exact address while you're still deciding, because that is the first time anyone puts a price on the risk.
Across the Bicknacre area, about 20% of postcodes rate high on at least one flood measure, about 20% medium and about 42% low. Those measures include surface water as well as rivers and the sea, and a postcode only has to trip one of them to be counted. So these shares aren't the same thing as the flood-zone figures above, and neither replaces the other.
Counted as individual properties, the Environment Agency's rivers-and-sea mapping lists 10 postcodes in the area with any risk at all, containing 341 properties. Six of those properties are at high risk, one is at medium risk and 19 are at low risk. Two of the six high-risk properties are homes. Postcodes with no river or sea risk don't appear in the list at all.
The share of postcodes inside the high-risk modelled flood extent is about 1% with defences included and about 1% without them. On the model's own terms, the defences make no visible difference here. "Defended" only means a defence appears in the model. It doesn't mean any particular house is safe.
The nearest coastline is about 1.1 kilometres from the closest postcode and about 4.7 kilometres from the typical one. The shoreline management plan for that stretch of coast says "hold the line" for the next 20, 50 and 100 years, meaning the stated aim is to keep the existing defences where they are. That's an intention, and it depends on funding that hasn't been committed. It doesn't describe what stands on the shore today, and the plan doesn't pay for anything itself.
Bicknacre's flood risk is a weak point. The rivers aren't the problem. The concern is how much of the village rates high once rain is counted.