So the foundation of your argument is
"water can be used but not owned; it belongs to everyone as part of the commons"
If water can't be owned, then what if I went to the grocery store and bought a case of bottled water. Can some guy come to me and TAKE my water without permission? If no, then the FOUNDATION of your argument is destroyed, and everything that you have built on your FOUNDATION falls down.
Enough said.

The "Scarce Resource" and "Tragedy of the Commons" arguments are two very important arguments that Libertarianism takes very seriously.  Indeed, in many ways, it is the unique answer to these two important questions, of “Scare Resource” and “Tragedy of the Commons” that makes the libertarian argument so interesting and compelling.  In fact, before answering those two questions, many libertarians were passionate liberals, that is, until we reasoned through these two arguments.   Because the libertarian reasons her way differently on these two fundamental arguments, the libertarian economic argument is often fundamentally different than the modern day "liberal" economic argument.  

With this in mind, we can see that the article against the privatization of water is wholly an argument inside the liberal economic paradigm.  Further, to the libertarian, the article confuses two important matters, one being privatization and the other being the legal field whereby corporate market control can manifest itself in negative ways.  So, the privatization of water discussion by Stephan Lendman and Vandana Shiva calls into question both arguments, "Scarce Resource" and "Tragedy of the Commons" and as well at the same time it confuses the market privatization issue with the issue of corporate control. I would like to address the liberal and libertarian divide on this, as briefly as possible.

First, the "Scarce Resource” argument.  While it is certainly true, water is indeed a scarce resource, it is not in any fundamental way different than other scarce resources.  In fact just about all resources are scarce and economists are correct to identify this as an important understanding when studying economic science.     The resources that are not scarce are codes, plans, formulas, copies, recipes, etc.  Economists correctly place these items into the basket of human asset knowledge, that once known, has zero costs, and so they give off “Positive Externalities” because they are not “Scarce Resources”.  Water certainly is a scarce resource, so the liberal economic argument and the libertarian economic argument do not diverge on this point.  Certainly historians and anthropologists and evolutionists can tell us stories of Mankind fighting and agreeing to various terms of usage over this very scarce resource called water.   

Next, we differ over how best to handle scarce resources, water in this particular case. Here, it is best that we say that libertarians, like liberals, seek a (1) wide spread, (2) nonexclusive, (3) fair, and (4) inexpensive use costs.  The disagreement comes over how to achieve those ends, or what is the best method to achieve those ends.  We libertarians find that the lesson to be learned from the “Scarce Resources” argument is that the scarcer, the more important is it that we do not have a commons, and instead insure a wide and open market for it.

Next, we differ over the lesson to be derived from the “Tragedy of the Commons”.  Simply stated, the liberal economic position often is that a “we”, often resulting in a single purpose department within government, must protect and enlarge the Commons for the benefit of all as well as the benefit of the Commons itself.  The lesson that libertarians draw from the “Tragedy of the Commons” is that the resource exploitation comes from the fact that the “scarce resource” is left in common, and so, in the steward of the unwatchful only generally interested collective.  

Finally, while both the liberal and libertarian argument to the "Scarce Resource" and "Tragedy of the Commons" question differs in a fundamental way, there is good news.  This is because, in the end, it’s a rational question that can be worked out through scientific reasoning, testing and rational dialog.  It’s not an answer that requires appeals to gods or devils or interpretations of ancient books.  The "Scarce Resource" and "Tragedy of the Commons" question, will call forth arguments from either the liberal or libertarian perspective and vested emotions may get in the way. But what really must take place is a full argument between these two, for the future of Water and our Planet hangs in the balance.   While I disagree with Stephan Lendman and Vandana Shiva over the water issue, I do not disagree with them personally.  Indeed, I respect them and their passion for the subject.  I can only hope they in turn take the time to explore the libertarian answers to these two important issues that always have faced Mankind, "Scarce Resource" and "Tragedy of the Commons".  They may just want to rework their position on water and join us, or if not, then enlighten us as to how our reasoning has gone astray looking for the answers to these two important arguments; "Scarce Resource" and "Tragedy of the Commons".