As a known lawyer here, you need to appreciate the water law of The West (and all the nuance involved). Unless otherwise over-ruled, it's at a state's discretion issue. IANAL, but I have considerable experience with water in the west; specifically, The Rockies. The oldest water rights are agricultural, so what takes precedence as a matter of law is geared towards that.

Edit: My solution is for the people wanting water rights need to purchase them from those that have them (i.e. the agricultural folks).