Wow. Coolshades, what a beautiful property! Interesting building technique, too. That is exactly what we want to do when we retire- move back to Virginia and get a small place on the water.
When we lived in the tidewater area (Western branch of the Elizabeth river), we had a neighbor with just such a driveway. It was a horseshoe shape with a raised, round, formal pond in the middle. I don't know if he had drainage pipes under the pond, as his drive was sloped towards the street. Maybe you could put a French drain around the pond, then a culvert going under the driveway to wherever you want the water to go.
The cool thing about it was those neighbors were from Taiwan, visited frequently, and would bring back some
really interesting plants.
There was always something very beautiful (or very illegal) growing in their pond.
I really miss Va.