Desert hiking is a completely different animal. My starting weight for a mountain hike of, say, six nights is around 25-26 pounds (base weight 13 lbs., water weight each morning 3-4 lbs., food at start 8 lbs., fuel at start 3/4 lb.) My starting weight for an out-and-back desert hike of one night is around 31-33 pounds (same base weight, 4 lbs. of food, less fuel, but a whopping 14-16 lbs. of water). I couldn't imagine doing a multi-day hike in the desert unless I was either sure of a water source or could somehow cache water.

When hiking in the mountains and camping near a water source, I don't stop and think about all the water I use re-hydrating food, washing, brushing my teeth, etc. When I'm in the desert I use water only for drinking. I actually find it more weight-efficient to bring hydrated foods such as pouch tuna or fresh vegetables so I don't waste water re-hydrating dried stuff. And if I bring the dog, she carries her own water.