Edit: I see all my points have been already stated in more or less the same words by the Anonymous Coward. 
Failure to read the whole thread before posting – loose one skill point.
Okay, I think I see the problem everyone has with this; there’s some inherent contradiction that need to be resolved. Take this horribly contrived hypothetical example:
You purchase your riverside cottage, and inherent in the value is that it is a riverside cottage. Thus, that there is flowing water by it is part of the property. If someone upstream were to dam the flow completely, there would no longer be a river flowing beside it, thus it’s value has been diminished. Is this not a property violation? Notably, if the river had been dammed before you moved there, the value to you would not be diminished and it would not be a property violation… maybe…
First and foremost, someone needs to define the terms of the debate. What does “property” mean, especially in the context of such flowing things… If someone were to purchase a sector of a solar system, do they then own all the comets and planets which pass through it? What about the person who owns the adjacent sector? what does he own?
What does property violation mean? Is it anything that diminishes the value of your property? Is it more general than that? Is it more specific?
With respect to this debate, I concurr that the concept of “reasonable use” is a fiction. But it is a useful fiction, and it does not do to denigrate it so.
Edit: I would concur with those above that what you own is the flow of water. Thus, in order extract water from the river, you must pay those downstream who will be denied this water by your extraction of it. Whether this applies to pollution or not is an interesting one, and one for you to debate amongst yourselves.