I wouldn't say that either is overpopulated. Arizona, in particular, has plenty of water and is sparsely populated. It has more square miles of mountains than S

I wouldn't say that either is overpopulated. Arizona, in particular, has plenty of water and is sparsely populated. It has more square miles of mountains than Switzerland. However, it may not have enough water to keep the huge cotton, alfalfa, and other water intensive crops growing. Agriculture is a huge industry in Arizona and it takes a lot of water to grow water intensive crops in the desert. This is done because water is extremely cheap and the sunshine gives you more harvests per year, and the lack of rain doesn't damage cotton. That's an issue of depleting aquifers via over-farming rather than too many people moving into the state and wasting too much water on showering and cooking. Another issue for the Phoenix metro is sprawl. But again, that's not a question of too many people so much as too many wanting to live on large per-person plots of land all connected to the Phoenix metro. You can be rural and have large individual plots in the Verde Valley or other more rural areas and you can have urban areas with higher density, but trying to make low density urban areas doesn't scale very well.