Henlow has a real flood risk, but it is confined to a small part of the village. Only a few postcodes fall in the river flood zones. More appear once rainwater on the roads is counted. A few dozen homes carry some rating, and about a dozen are rated high. The nearest tide gauge is a very long way from here, which tells you how much of a coastal problem this is.
On the Environment Agency's river-and-sea mapping, about 3% of Henlow's postcodes are in flood zone 3, the highest-probability zone, and about 5% are in flood zone 2. The two zones are separate bands, with zone 2 the medium-probability fringe beyond zone 3, so a postcode counted in one is not counted again in the other. About 2% of postcodes fall within an area that has flooded before.
Surface water has no separate figure for Henlow here. It is folded into the postcode indicators further down this page, so the gap between those figures and the zone shares above is mostly rain with nowhere to drain.
With the Environment Agency's allowance for climate change added, about 10% of postcodes fall in a flood zone. That is a modelled look forward from the same mapping, and the line it draws is wider than today's.
For most Henlow buyers, insurance should be routine. For the minority in the zones or rated high, expect the insurer to ask more questions and price the answers in. Put the exact address into the Environment Agency's long-term flood risk service and get an insurance quote while the survey is still being booked, because the postcode-level picture can hide a lot of variation between neighbours.
Counted by postcode across several measures at once, rivers, sea and surface water among them, about 9% of Henlow's postcodes rate high on at least one, 17% rate medium on at least one and 45% rate low on at least one. A postcode only needs one of those measures to land in a band, so these shares run higher than the zone figures, and they include rain as well as rivers.
Counting homes is more useful than counting postcodes. The Environment Agency's rivers-and-sea mapping lists 168 properties across the 13 Henlow postcodes that carry any risk at all. Of those, 13 are rated high, 22 medium and 24 low, and 12 of the high-risk properties are homes. Postcodes with no risk on that mapping are not listed, so these are the only properties with a rating to report.
In the Environment Agency's model, about 8% of Henlow's postcodes fall inside the high-probability flood extent with no defences counted, and the share is still about 8% when defences are counted. A defence that is present in the model does not keep a house dry by being there, and here the line on the map ends up in the same place either way.
The nearest tide gauge is at Portsmouth, where sea level rose at about 2 millimetres a year across its record from 1962 to 2023. That is the rate measured at Portsmouth over those years, and Henlow's flood risk comes from somewhere else.
Flood risk in Henlow is middling. Most of the village sits clear of it, and a small cluster of homes carries real exposure that no defence in the model removes.