Yes, in parts, and the parts are the ones nearest the water. Around one postcode in five carries a high rating on at least one flood measure. Roughly one in ten sits inside the highest river zone. Two floods show up in the formal record. Dartmoor collects the rain, the Tavy carries it downhill, and the town exists precisely because that river was easy to cross.
Taking rivers and the sea first, the Environment Agency's mapping puts 9% of the town's postcodes in flood zone 3, the high-probability band, and a further 7% in zone 2. Those two are separate rings rather than one inside the other: zone 2 is the additional medium-probability fringe sitting beyond zone 3, which is why it can be the smaller figure without anything being wrong. Between them they describe the low ground along the Tavy and its approaches, not the town as a whole.
Surface water is the risk that never gets its own headline. The published mapping for a town this size does not break it out as a separate share, so it sits folded into the combined postcode indicator further down rather than standing on its own. What the formal record does hold is two flood events, the most recent in December 1979, when the main river exceeded its channel capacity with no raised defences involved.
Looking forward, the Environment Agency's climate-adjusted extent covers 19% of postcodes. That is the footprint the modelling expects once allowance is made for a wetter century, and it is roughly double the current zone 3 share, which is the number worth carrying into any conversation about a thirty-year mortgage.
For insurance, none of this makes cover impossible, but it does make it a question you settle before you exchange rather than after. Get an indicative quote on the specific address, not the street, and expect the excess rather than the premium to be where a flood history shows up.
At postcode level, taking all measures together including surface water, 22% of Tavistock's postcodes rate high on at least one indicator, 17% medium and 35% low. Those bands overlap with the river-and-sea zones above rather than adding to them, so a postcode can appear in both counts. It is a screening tool, not a verdict on a house.
Counted as homes rather than postcodes, the Environment Agency's rivers-and-sea mapping lists 2,207 properties across the postcodes that carry any risk at all, with 508 at high risk, 145 at medium and 519 at low. Of the high-risk properties, 353 are residential. Postcodes with no risk do not appear in that list at all, so this is the affected slice of the town, not the whole of it.
On defences, the modelling is blunt. The high-risk extent covers 9% of postcodes in the undefended version and 9% in the defended version, which is to say the modelled defences do not change the footprint. Defended means a defence exists in the model. It does not mean a given house is protected, and nobody should read it that way.
Shoreline policy is close to irrelevant here, and worth saying so plainly. The nearest coast is about 4 kilometres away with a median of roughly 5 kilometres, and the shoreline management policy covering the area is no active intervention across the twenty, fifty and hundred-year horizons. A policy is a stated intention about maintaining coastal defences, not a defence itself, and here the intention is to do nothing, because the sea is not what floods Tavistock.
For completeness, the nearest tide gauge at Devonport recorded sea level rising by about 2.4 millimetres a year across its 1962 to 2015 record. That is a measured historic rate rather than a forecast, and it matters to the estuary far more than to a market town this far up the valley.
Flood risk is the weakest thing about Tavistock, and it is weak in a specific, mappable way rather than a general one. Put the exact address into the Environment Agency's long-term flood risk tool before you fall in love with the kitchen.