Yes, and in a large part of the village it is a real risk. About one postcode in six is in the highest river flood zone. About a third are at high risk on at least one measure. More than a hundred properties are mapped at high risk from rivers. Flood risk is the part of Bassingbourn's file that most deserves a careful read.
In the Environment Agency's river-and-sea flood zones, about 17% of Bassingbourn's postcodes are in Flood Zone 3, the highest-probability band, and about 2% are in Flood Zone 2, the medium-probability band. The two zones do not overlap, so the 2% is in addition to the 17%. Bassingbourn is nowhere near the sea, so all of that risk comes from rivers and streams.
The Environment Agency does not publish a separate surface-water share for the village. Surface water appears instead in the wider postcode measure below, which combines it with rivers. On average, homes here are about 160 metres from the nearest water, close enough that water running off fields and lanes is a concern alongside the rivers themselves.
The Environment Agency's climate-change version of the river-and-sea zones puts about 21% of Bassingbourn's postcodes inside the flood zones. That map shows how the zones are expected to shift as rainfall patterns change.
For insurance, a home in Flood Zone 3 is a harder sell than one on higher ground a few streets away, and premiums and excesses reflect that. A buyer who learns about the risk from the insurer after exchanging contracts has the timing the wrong way round. Put the exact address into the Environment Agency's long-term flood risk service and get an indicative insurance quote while the purchase is still easy to walk away from.
Counting every flood measure together, surface water included, about 32% of Bassingbourn's postcodes rate high on at least one, about 17% rate medium and about 51% rate low. A postcode can show up as high risk because of one indicator alone, which is why this share is bigger than the river zones.
The Environment Agency's rivers-and-sea mapping counts properties as well as postcodes. Across the 20 postcodes it lists in Bassingbourn, 519 properties appear: 116 at high risk, one at medium risk and 34 at low risk. Of the 116 at high risk, 106 are homes. Postcodes with no risk at all are left off the list completely, so it does not count every home in the village. The gap between medium risk and high risk is almost empty, so a property is usually either well clear or squarely at risk.
In the Environment Agency's model, about 17% of Bassingbourn's postcodes are inside the high-risk extent without defences, and the same 17% are inside it with defences included. Wherever the model includes a defence, it does not shrink the high-risk area. A defence appearing in the model only means something is there, not that it protects any particular house.
The Environment Agency has no recorded historic flood outlines anywhere in Bassingbourn. That is reassuring as far as it goes, but it only covers floods that someone mapped, and a flooded garage in a side street can go unrecorded.
Flood risk is one of Bassingbourn's weakest areas. A sixth of the village is in the highest river flood zone and modelled defences do not reduce that, so every individual house needs checking.