Bodmin is not a flood town, but it has flood streets. Roughly three in a hundred postcodes sit in the highest river and sea zone. Widen the definition to include water coming off the hills rather than up the channel and about one in ten catch something. Only a couple of dozen homes carry the top rating. The town-level answer is comfortable, and the town-level answer is not the one you are buying.
On the Environment Agency's river and sea mapping, about 3% of the town's postcodes fall in flood zone 3, the highest-probability band, and about 1% in flood zone 2. Zone 2 being the smaller number is not a mistake in the mapping. Zone 2 is the extra medium-probability fringe that sits beyond zone 3 rather than a wrapper containing it, so the two shares are separate bands and adding them together is the standard error people make when reading a flood map for the first time. The recorded flood register holds four events for the area, the most recent dated 24 September 1976 and attributed to a main river.
Surface water is the risk that does not appear on any of that. The river and sea zones only describe rivers and the sea, so a property can sit outside every zone on the map and still take water off a saturated slope, through a blocked gully, or down a road that turns into a channel for twenty minutes during a summer downpour. It is the failure mode that surprises buyers, because nothing in the conveyancing pack draws a blue line round it.
Looking forward, the Environment Agency also publishes a climate-adjusted zone that allows for higher flows in future. That extends the affected share to about 4% of the town's postcodes, which is a modest widening rather than a redrawing of the map.
For insurance, none of this is priced at town level. Underwriters quote against the address, its history, and its position relative to the modelled extents, so two houses on the same street can be quoted very differently. Get an indicative quote before you instruct a solicitor rather than after, and ask the seller directly whether the property has ever taken water, because a previous claim shapes the premium more than any map does.
The broader postcode indicators, which fold surface water in alongside rivers and the sea, put roughly 10% of the town's postcodes at high risk on at least one measure, about 14% at medium and around 35% at low. Those bands overlap with the zone shares above rather than sitting on top of them, so they are a different lens on the same town, not an additional pile of exposed streets.
Counted as homes rather than postcodes, the Environment Agency's rivers and sea mapping identifies 650 properties across the 32 postcodes that carry any risk at all. Of those, 34 are rated high, 82 medium, 98 low and 52 very low, and 22 of the high-risk properties are residential. Every postcode with no risk is simply absent from that list, which is why the count of homes is the number worth carrying around and the share of postcodes is the number that makes people either relax or panic for no good reason.
On whether anything stands between the water and the house, about 3% of postcodes sit inside a modelled high-probability extent with no defence present in the model, and about 2% sit inside one where a defence is present. Present in the model means a structure has been included in the mapping. It does not mean the house is protected, it does not describe the condition of the structure, and it is not a reason to skip the survey.
Every postcode in the area falls under a shoreline management plan, which reads oddly for a town whose nearest coastline is about 5 kilometres away at its closest point and closer to 7 kilometres for the typical postcode. The stated policy over the next twenty years is to hold the line, and over the fifty and hundred year horizons it shifts to managed realignment. A policy is an intention to maintain or move defences over that period. It is not a guarantee of funding, and it is not a defence that already exists.
At the nearest tide gauge, at Devonport, the measured record from 1962 to 2015 shows sea level rising at about 2.35 millimetres a year. That is a historic rate from an instrument, not a projection, and for an inland town it matters mainly through what it does to river levels downstream over decades.
Flood risk here lands somewhere in the middle: unremarkable for most of the town, genuinely serious for the handful of properties sitting in the wrong dip. The address decides this one, and no amount of reassuring town-wide arithmetic will decide it for you.