Sorry BMB, being on top of a hill won't save you from flooding.

Here in Gainsborough, Lincs (UK) we had flooding after a long period of heavy rain in August 2004. My bungalow next to the River Trent was fine but houses in the uphills area were flooded because the drains up there couldn't cope with the water.

More recently in the flooding that hit our area about a month ago, the village of Blyton just north of Gainsborough (where I used to live)was flooded for days - because the hilltop there has a clay cap about 4 feet underground and the land above just gets saturated. So for a few days, us people living at the bottom of the hill were fine and dandy while those at the top were under 3 to 4 feet of water.

The other problem about building on a flood plain, apart from the fact that you may get flooded, is that the profile of the flood plain changes and this can cause problems in other areas. On the opposite side of the Trent to Gainsborough, the land is kept mainly clear and is farmed but the farmers know that it is likely to flood. When that does happen, a not uncommon occurence, the main road linking Nottinghamshire to Lincolnshire is impassable. I was at a meeting where the business community asked the Environment Agency why the road could not be raised to keep it clear of the flooding. The EA explained that this would change the characteristics of the flood plain and make other areas locally flood - ie: the flood plain wouldn't be able to do what it was designed for.

BBP