Go back to the person who sold you your house, MAKE them contact the
builders and ask them how they arranged drainage of the gardens. I'm
perfectly serious about this. Do it now.

--
Sacha

I'm aware of the drainage situation. In fact, we probably have 12-15" of
topsoil on top of a 5' layer of clay. Not ideal, I know, but standard on
this particular site. Close to both ends, there is a soakaway, and drainage
pipes too and I also myself layed a french drain down the middle of the
garden joining the two. The areas in concern, don't mirror where there is
either a soakaway, or not, In all the rain we had last winter, and some
bad spells many months ago, drainage has never been an issue.

Neil