This is indeed a very interesting topic and I know that I have not found one branch of anarchist thinking that can define my own opinion of best practice.

I define anarchy as no artificial hierarchies, no immoral use of power over. Be it, the legal state coercive kind, brute force, intellectual trickery, or a first come first served mentality. Land and resource organisation is going to be one of the defining factors in the evolution of anacho-society.

Personal I think we need watershed based fractal communal federations to make agreements on primary resource uses, with consensus from everyone directly influenced by said uses.

How can one stop the 'owner' of the upper river from polluting those below?

'Air, water, food, shelter, comfort and pain,
Creative tribes based on trust and mutual gain.'