I would check with an environmental law professor, such as Jan Laitos at the University of Denver School of Law, or a property law professor, possibly Tom Kleven at Texas Southern University. Good luck!

You might also check the University of Washington school of law professors - I am not sure who to contact - because Washington has many rivers, some that border other states, and WA has made marijuana legal for recreational purposes. Same with Colorado - check in with the University of Denver School of Law or UC Boulder School of Law.

In double checking your question, I may have misunderstood. Still, I would contact a law professor in a state with many rivers. 

Dear Deana,

Thank you so much for your kind help and advise, this software is developed by a decision support system group in Waterloo university -Canada, so is any publication on the application of this GMCR II in transboundary rivers it will highly appreciated and acknowledgment ,looking to get your kind help

The folks that developed GMCRII have upgraded the software; called GMCR+. You can probably get ahold of Dr. Keith Hipel and see if you can get a copy. 

Thank you so much dear Dr. Mark, I try to contact Dr. Hiple

Best regards

Ramadhan