Haddenham's flood risk is middling, and almost none of it comes from rivers. Hardly any postcodes fall inside the river flood zones. A minority show some risk once rainwater running off the ground is counted. The village has one flood on record, and it is a long way back. Water lying in the wrong place after a storm is the risk worth asking about here.
On the Environment Agency's river-and-sea flood zones, no postcodes in Haddenham and the surrounding villages fall in zone 3, the highest-probability band. Fewer than 1% fall in zone 2, the medium-probability fringe outside it. The Environment Agency has one recorded flood on its books, in December 1992, when a main river ran over the top of its channel with no raised defences to hold it. For a place in the Vale of Aylesbury, that is a short file.
Surface water is a different matter, because rain does not need a river to cause a problem. On the measures that include it, more postcodes come into view, and the gap between those numbers and the river zones is surface water and the other non-river sources. A house with no river in sight can still sit at the bottom of a slope that drains its neighbours' gardens. The Environment Agency's long-term flood risk service has a surface water layer, and the exact address is worth putting into it alongside the river map.
The Environment Agency also models a flood zone allowing for climate change, and under 1% of postcodes in the area fall inside it. On the agency's own forward view, the river picture barely changes.
For insurance, a near-empty river zone is the part underwriters like to see. Surface water risk is assessed separately and can still show up in a quote for a particular house, so a cheap premium on one cottage says little about the one at the bottom of the lane.
Counting postcodes that rate high, medium or low on at least one of several measures, surface water included, about 7% of Haddenham's postcodes come out high, 7% medium and 18% low. Each postcode is counted on its worst measure, so one bad indicator is enough to put it on the list, even if every other measure is clean.
The Environment Agency's rivers-and-sea mapping lists only postcodes that carry some risk, and in this area that is seven postcodes containing 132 properties. Of those, 8 properties are at high risk, 3 at medium and 7 at low, and none of the high-risk properties is residential. A count of homes is the more useful figure here, and the river answer is small.
None of the area's postcodes falls in the high-risk modelled flood extent, either with defences or without them, and about 0.3% fall in the low-risk extent without defences. The Environment Agency's models note where a defence is present. They do not certify that a house behind one will stay dry. Here the question barely arises, because the modelled water reaches so little of the area.
The nearest tide gauge to Haddenham is at Portsmouth, where sea level rose by about 2 millimetres a year across its record from 1962 to 2023. That is a rate measured on the south coast over six decades, and a village in the middle of the Vale of Aylesbury has rather more pressing worries.
Haddenham's flood risk is middling. Rivers barely trouble it, and surface water accounts for most of what there is.