something similar happened to us this year as well. i live in an area in d4 that was flooded when the river Dodder flooded in 2002, and since then millions have been put into flood defence's. houses on my street were flooded but ours was not, we obviously did not make a cliam against our ins, in fact i dont EVER remember claiming for anything.
in May our ins was due and we decided to shop around, but because our area is now deemed to be still a flood risk several companies inc our bank would'nt even quote us, so we had to stay with our original provider.
none of the companies we asked would even consider the flood defences
surely this is the same as saying your neighbour has had a car crash so now we wont insure you in your car