Ryan
The simple answer is lots of drainage!
We put in several layers of drainage. We've around 110 catch basins dotted about, which fall directly into the main drains. These mains are not so long, as we dug out 2 kilometres of new ditches.
Mostly, we concentrated on perforated land drains. There is something like 35,000 metres out there at 6-8 metre centres throughout the fairways and semi-roughs. We had problems with this, because you generally cut perf pipe into an established grass surface, so ensuring surface water can reach the drain trench. We had to put the drains in before topsoil was returned, which meant we had hundreds of sand topped trenches at the surface. We tried to place the topsoil between the trenches, but it was impossible, so we decided to abandon that idea and spread the topsoil as normal, with a thinner topping of topsoil over the trench lines. Immediately, this negated the drain function, but we had a plan for that.
Prior to seeding, we spread a thin veneer of sand over all the fairways. It wasn't a sand cap as such, as it was too thin to serve a drainage function, but it gave us a smooth, clean seed bed. We selected a rye/fescue blend for the fairways and surrounds, in recognition of the clay soils. The rye pops quite quickly, which helped us with the final part of the plan.
As soon as the fairways had enough heft to support a vehicle, we sand-banded the entire drained area, diagonally across the line of the perforated drains. This process cuts inch wide, 8 inch deep slits at 250mm centres and immediately fills it with sand. This gave us the surface drainage link. The analogy I use is that if you consider the buried perforated drains to be motorways then the sand bands are the slip roads. As long as the sand bands intersect with the sand in the drain trench then the surface water will reach the drains.
An agronomic benefit of covering the drain lines with topsoil is that the grasses have a uniform growing medium throughout the site and we have less trouble with the drain lines showing during times of drought. You can see the benefit of this in the newly updated Google Earth aerial of the course.
Also, winter play is going to be minimal, so they can ensure the course goes into the summer in tip top shape.
As Adam Lawrence will attest, the site was one of the stickiest you could ever imagine. It's no wonder they made bricks out of it! Our scheme has dried out the soil tremendously well and your shoes should stay pretty clean, so long as you don't wander off into the undrained far roughs!
I hope this answers your question satisfactorily.