Living in the Southwest USA requires wise use of water.  When arriving from other sections of the country, the extremely low humidity means you will have to drink lots of water. 

But because the area is semi-arid, you also need to use water wisely and conserve deeply.  Turn off the tap when brushing your teeth; take short showers; don't let the water run without using every drop; use commercial car washes to wash your car, not domestic water hoses; let the hotel manager and the restaurant manager know if there is a toilet that continuously runs or a water spigot that drips.  Most hotels have water saving requests for you; such as re-using your towels.  Most restaurants serve water only when requested.  If you ask for a glass of water, drink it, and don't waste it.

 Do not take water for granted in the Southwest.  It is precious.