Tetbury has almost no river or sea flood risk, but rain running off the hills is a different story. None of the town's postcodes falls in a river flood zone. About one postcode in nine carries a high flag once surface water is counted. About a quarter carry at least a low one. The sea is a very long way off.
In the Environment Agency's river-and-sea flood zones, 0% of Tetbury's postcodes fall in zone 3, the highest-probability band. Another 0% fall in zone 2, the medium-probability fringe beyond it. The Tetbury Avon, known locally as the Ingleburn, rises just north of town, so here it is only a stream and nowhere near big enough to put the town on the river maps.
Surface water is where Tetbury's risk actually lies. The town is set among gently rolling hills, and when heavy rain falls faster than drains and fields can take it, the water runs downhill along roads and into whatever low ground it finds. Being outside the river zones says nothing about this kind of flooding, which is why a house can be described as "outside the flood zone" and still have a surface-water flag on the same street. The government's long-term flood risk service shows surface-water risk for each address, so look up the exact house there and not just the town.
The Environment Agency's climate-adjusted flood zone, its look ahead at river and sea flooding under future conditions, also covers 0% of Tetbury's postcodes.
For insurance, being outside the river and sea zones counts in most homes' favour. A home with a surface-water flag may get more questions from insurers and a higher premium, and a quote for the specific address will tell you more than the town-wide picture.
Across the 190 postcodes measured, about 11% rate high on at least one flood measure, 15% rate medium and 25% rate low. That measure counts a postcode if any one of several indicators flags it, including surface water, which is why it shows risk where the river zones show none.
Counting individual properties, the Environment Agency's rivers-and-sea mapping lists only eight Tetbury postcodes as carrying any risk at all, covering 204 properties. Of those, 11 properties are rated high, two medium and four low, and eight of the 11 high-risk ones are homes. That is a short list, and it counts buildings, so it can be compared directly with the size of the town.
In the Environment Agency's modelled high-risk flood extents, 0% of Tetbury's postcodes fall inside either the undefended or the defended version. So the question of whether a flood defence protects you never comes up here, because no postcode falls inside either extent.
The nearest tide gauge to Tetbury is at Portsmouth. It recorded sea level rising by about 2 millimetres a year between 1962 and 2023. That is the rate measured on the south coast over those years, and Tetbury is a hill town nowhere near it, which tells you most of what you need to know about the town's exposure to the sea.
No historic flooding is recorded anywhere in the area. That is genuinely reassuring, though it only covers what someone wrote down, and small surface-water floods often go unrecorded.
Tetbury's flood risk is middling and almost all of it comes from surface water. The rivers and the sea are no real threat, and the downhill run of water after a heavy storm decides how much any particular house is exposed.