SGH is built on the same belt of sand that runs through a good bit of Surrey and Berkshire. There are many courses with the same sub soil, The Berkshire, Sunningdale, Swinley, Camberley Heath, the three W’s at Woking. This sand is very fine, almost silty, it is stable and many metres deep. I would therefore suggest that washouts are not a problem. In fact if you look next to the bulldozer tracks, or steps as we like to call them, in post #24 you can see where erosion has revealed the underlying sand.
The question is, what do we think of the new bunkers compared to the old ones and could they have reproduced the originals. My personal opinion would be, not a lot and yes.