>>512018104I do extensive research for fun and have been to every corner of AZ and seen every mountain range in AZ with my eyes. I've lived in AZ my entire life but was born in California.
The reason many southern California and AZ washes are mostly dry now is due to various practices done by industrial corporations and poor city management, and also do to economic benefit (namely exotic crop farming for profit on industrial scale, where most of the farmland is actually not for subsistence food production locally).
-concrete linings, they separate the water table partially from the aerial processes and most importantly soil moisture processes from plants. Every wash even extremely dry ones actually have flowing water underground beneath them. To coax the water back up you need either good climate conditions or you need to create an ecological moisture retention program through rock dams (slow the water and build sediment), building green banks (slows water and builds sediment), and shade. All of which raise the water table.
-industrial and exotic or excessive farming pumping operations, this depletes the river water levels to unsustainable levels to maintain equilibrium between evaporation and seepage vs total inflow and precipitation. This also depletes ground water and soil moisture, and thus kills plants off further drying the soil and air and creating a decertifying feedback loop. It is possible to farm on large scales with less exotic and hardy species for local and widespread food production, but it is less profitable to do so which is why many jews and normal farmers do not like this.
-cattle farming beyond the capacity of a watershed, cattle can literally reduces total flow volumes on rivers in semi-arid climates by more than 50%. They do this by trampling and eating all bank vegetation and shade tree saplings, this reduces soil and air moisture and lowers the water level while raising the evaporation rate and water turbidity.
