I don't believe it. According to an Insurance company's underwriters, I live in a high risk flood area.
I discovered this information whilst getting some quotes together for home insurance, and said company called me back with the news.
Conversation as follows:

Them: "Good morning Madam, this is (insert name) calling from (let's just call them stupid from now on shall we?) we are calling to inform you that we are unable to insure you at our normal rate as you are living in a high risk flood area, but we can help you by insuring you at a higher premium which I'm sure you will find is a competitive price considering your situation"

Me: "Huh? flood area? No I don't"

Them: "Madam, I can assure you that you do"

Me: "But I've lived here for thirty years, it's never flooded"

Them: "But Madam, many of your neighbours have claimed on their insurance due to flood damage"

At this point I did a quick mental recky of the situation. I know my neighbours. It definitely hasn't flooded here and I live on a hill. Unless they'd been making fraudulent claims and the insurance companies had been paying out without requesting any evidence of flood damage, then the insurance company had their facts wrong.

Me: "I think you must have your facts wrong somewhere, This area has never flooded, it's on top of a hill, none of my neighbours have ever been flooded"

Them: "Madam, we asked our specialized underwiters to provide us with information pertaining to your postcode, and we can assure you that you live in a high flood risk area, you live right next to a river"

Again, I did another quick mental calculation. Yes, I do live 'near' a river, but said river is about 1/4 of a mile down hill from me. This river, The Brent, runs under the Wharncliffe Viaduct. The Viaduct is 65 feet high at its peak, and reaches its lowest height right next to my house. The average depth of the Brent is about 2 foot, max round here. Now correct me if I'm wrong (I'm not a scientist or a meteorologist, and I'm also crap at maths) but if the Brent were to rise enough to cause damage to my house, it would have to reach around 60 feet, which would more than likely mean that the whole of London would be in some pretty serious trouble as well.

I pointed this out to them.

Them: "Madam, I can assure you that our underwriters have their facts correct. You live in a high risk flood area"

Me: "No I don't"

Them: "Yes you do!"

Me: "No, I really don't!"

Them: "You do!"

Me: "Bloody don't, I'm telling you!"

Them: "Madam, we can sit here and argue all day if you'd like, but the fact remains that our underwiters are correct in their facts. We can provide you with our premium rate insurance right now if you have your credit details ready"

Me: "Pi** off"

I checked with the Environment Agency just in case.

This is what they said:

"The location you have selected is in an area which fell outside the extent of the extreme flood, at the time of our assessment of the likelihood of flooding. Generally this means that the chance of flooding each year from rivers or the sea is 0.1% (1 in 1000) or less. The Flood Map shows our current best information on the extent of the extreme flood from rivers or the sea that would occur without the presence of flood defences".

Needless to say, I went with another insurance company.