Earlier quoted context omitted.
We have to. Arizona is at the bottom of the water rights agreement among the states drawing from the Colorado River. I see a lot of water harvesting structures here, often in the form of parks and greenways.
That’s actually not true, IIRC per capita we are actually better off than California and Nevada. Edit: Just looked it up and california gets about 5 million acre feet (maf), AZ gets about 2.8maf and Nevada only gets 0.3maf. So per capita, AZ is doing pretty well allocation-wise.
When there is not enough water, priority goes to those holding senior water rights.
(Complicating this is that various tribal nations have water rights senior to the states, and it is only now affecting allocations)