Ha, the piling lads called it the moat. They mentioned that their boss had recently bought them all new wellies. However the strong implication was that he was a bit cheap as every single boot had a least one hole in it. You don't want freezing cold moat water in your boots.
Work is starting on the foundation masonry on Monday, they are pretty pleased that they won't have to bend down so much as the beam is out of the ground. I'm planning to be nice and go and pump out the moat at the weekend to make things as dry as possible for them.