it isn't baffling at all! some poster don't seem to understand where floods come from. A body of water flowing down hill will flood higher properties before lower areas, in fact lower areas might be left totally untouched in the water is soaking away as it flows.
And the idea that "local knowledge" trumps EA data is just silly. If a property is given a once in 75 year chance of flooding, that means it has a 1/75 chance of flooding each year NOW, not that it is likely to have flooded once in the last 75 years, or even the last 200 years.
A property could have a once in 75 year chance of flooding this year, but 30, 40, or 50 years ago a ZERO chance of flooding. The environment changes, land is built on, flood defenses come on line or are abandoned, most significantly , selfish cunts pave over their front gardens because they feel entitled to a parking space (should be a criminal offence with a ten year jail term - one day it will be, I'm sure)
so never having flooded does not mean is unlikely to flood, and being on higher ground does not mean less likely to flood.
use the EA data, they have the most up to date models available, and publish the information for everyone's benefit and information - plenty of know-it-alls on here think they know better, but don't listen to their ignorance