For most of Chalford the flood risk is low, but it isn't zero, and it collects on the valley floor. Only a small share of postcodes falls in the highest river flood zone. About one in ten scores high on at least one flood measure. No flooding has been recorded across the area. Homes up the slopes and homes down by the river carry quite different risks, even when they share a postcode prefix.
The Environment Agency's river-and-sea flood zones put about 6% of Chalford's postcodes in flood zone 3, the band with the highest chance of flooding from rivers. None are in zone 2, the medium-probability fringe beyond it. The river's floodplain in the Frome Valley is narrow and deep, so a postcode is either in it or clear of it. The weavers built their cottages up the hillsides because the valley floor was already taken by mills, and that choice of site has aged well on a flood map.
Surface water is the other route in. Rain runs off the steep valley sides fast, and the Environment Agency's surface-water mapping counts that risk separately from the river. Here it is folded into the postcode-level measure below and not broken out on its own.
With the Environment Agency's allowance for a changing climate, the river-and-sea zone grows to cover about 7% of postcodes. That is a modelled view of a wetter future, and the change shows up at the edges of the valley floor, where some streets sit just outside the current zone.
Insurers price individual properties, so the result depends on which side of the floodplain line your house falls. A cottage on the hillside and a converted mill by the water can sit in the same parish and get very different quotes. 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 at the offer stage, and do both early for anything near the river or the canal.
On the wider postcode measure, which counts a postcode if it rates on any of several flood indicators including surface water, about 11% of Chalford's postcodes rate high on at least one, about 8% medium and about 18% low. This is a broader net than the river zones, so its shares come out larger, and the two sets of figures describe different things.
Counting buildings instead of postcodes, the Environment Agency's rivers-and-sea mapping lists 253 properties across the 15 Chalford postcodes that carry any river risk at all. Of those, 106 are at high risk, 12 at medium risk and 15 at very low risk. Of the high-risk properties, 31 are homes. Postcodes with no river risk don't appear in that count at all.
As for defences, about 6% of Chalford's postcodes fall inside a high-risk flood extent that the model shows as defended, and about 4% inside one that is undefended. "Defended" only means a defence appears in the Environment Agency's model. It doesn't promise a dry kitchen, and it is the word a sales particular will lean on hardest.
The nearest tide gauge is at Portsmouth, where sea level rose by about 2 millimetres a year across the record from 1962 to 2023. For a village this far up a Cotswold valley, the sea is a long way down the list of concerns.
No historic flooding is recorded for the Chalford area. That is real reassurance, though a lack of records only means nothing made it onto the official register, and it can't promise that no cellar has ever taken water.
Chalford's flood risk is middling. Most homes on the slopes face little, and a small group of properties on the valley floor carries real risk.