Well, the economic aspect of things is essential just as physical constrains. You can't wish away certain things like availability of other resources, or people

Well, the economic aspect of things is essential just as physical constrains. You can't wish away certain things like availability of other resources, or people behaving responsibly with no economic incentive. Talking about water reserves. I actually have my own well that I went through the approval and build process about a decade ago(in EU). I had to declare "maximum consumption per day". So my point is, there is some (at least theoretical) conservation of groundwater resources. However there is no real way to check factual use for which I don't think there is an acceptable solution.