Jim,
My take is that sustainability is probably a bit easier in the south, but really, there are just challenges in every area.
As for Bradley's questions, I don't think there is a blanket answer as to what is sustainable, in this big continent (or in Europe, Asia, or Australia) I think its very site specific.
There are many areas, like MN where water is plentiful, and is likely to never run out, as they are net losers of population. In AZ, population grows, water is more scarce, etc. and the challenges become greater. Just examples. Plus, I saw a website the other day where they were talking about cutting back water use because there were water supply problems in Africa. To me, that is really mixing up some messages! Just because the economies of some third world nations haven't developed the infrastructure to deliver water isn't a reason for most of us to not play golf, is it?
That third world thing affects golf development. Years ago, when I did a course in Indoesia, the muni water supply was very small. We designed a gravity feed catchment system to capture the 100" of rainfall per year, although I heard the course was taking the city water anyway. On the other hand, tourism was a great way for this little island to develop their economy further (along with $4 a day Nike shoe making) So, does the golf their contribute or take away from the lives of the locals?
For that matter, in small US towns water can be an issue. At K State, the course water usage was nearly that of the whole town in hot summer months, although I don't recall the exact numbers. Some areas are just harder to provide water (no wells in that part of KS) but there is no way a one size fits all national directive fits any enviro bill.
A complex issue, but I agree with those who figure the economics into sustainability. Its only the wealthy countries that have been able to afford to even look at environmental sensitivity at least so far.