Mostly not, but the exceptions are specific and they matter. Most of the town sits outside the river flood zones entirely. A minority of postcodes carry a high rating on at least one flood measure. Two rivers run through a town sitting at the foot of high moorland, and water off high ground does not hang about. Flooding here is a street question rather than a town question, and the two answers are nothing like each other.
Start with rivers. The Environment Agency's flood zone 3, the higher-probability band, covers about 9% of the town's postcodes. Zone 2, which is the additional medium-probability fringe lying outside zone 3 rather than wrapping around it, covers about 5%. The smaller number is not an error and does not contain the larger one. Together they describe the low ground near the water, and the rest of Okehampton is not in a river flood zone at all.
Surface water is the risk that catches people out, because it does not need a river to be nearby. Rain that falls on high ground arrives at the bottom fast, and a lane that has never seen the Ockment in its life can still take half an hour of the wrong sort of downpour badly. There is no separate published surface-water share for the town here, so it sits folded into the combined postcode indicator further down rather than standing on its own.
Looking forward, the Environment Agency's climate-adjusted extent covers about 21% of the town's postcodes. That is the modelled footprint once allowance is made for a wetter century, and it is the figure a buyer planning to be in the house for thirty years should be reading rather than the present-day one. It roughly doubles the exposed area, which is the sort of change that shows up in a survey long before it shows up in a street.
For insurance, none of this makes cover impossible, and most of the town will never notice the question. Insurers price the address, not the postcode and certainly not the town, so a quote for a house on the low ground near the water and a quote for one on the higher ground can look like two different countries. Getting an indicative quote before instructing a solicitor costs nothing and settles the argument early.
On the combined postcode indicators, which fold surface water in alongside rivers and sea, about 7% of the town's postcodes rate high on at least one measure, about 8% medium and about 25% low. Those bands overlap with the river zones above rather than adding to them, so anyone tempted to stack the percentages into a total is building a number that does not exist.
Counted as homes rather than postcodes, the Environment Agency's rivers-and-sea mapping lists 1,293 properties across the postcodes that carry any risk at all, of which 65 sit at high risk, 83 at medium, 396 at low and 187 at very low. Forty-five of the high-risk properties are residential. Postcodes with no risk do not appear in that list at all, so it describes the exposed edge of the town rather than the town.
On whether anything stands in the way, about 8% of postcodes sit inside a high-probability flood extent with no defence in the model, against about 3% where a defence is present. Present in the model means a structure exists in the mapping, not that the house behind it is safe, and defences are built to a standard rather than to a promise.
Sea level is background rather than a direct threat this far inland. The nearest tide gauge, at Devonport, recorded a rise of about 2.35 millimetres a year across its 1962 to 2015 record. That is a measured historic rate at the coast, not a forecast for a town on a river at the edge of a moor.
No historic flooding is recorded across the town's postcodes. That is genuinely worth something, since a place with a history of it usually has the records to prove it. It is not the same as proof that no street here has ever taken water, and anyone buying on the low ground should ask the seller directly rather than treating a blank record as a guarantee.
Flood risk in Okehampton lands somewhere in the middle: not a reason to walk away from the town, not a box you can leave unticked either. The bulk of the housing is clear of it, a defined minority is not, and which of those two you are buying is a question the address answers in about ten seconds on the Environment Agency's own map.