I was going off 100 gallons per day per person, which is typical, but can obviously be improved upon. But that said, I don’t want to pay $7000 per year just for water. Plus living remotely like that is just terribly inefficient in general: food, trash, heating/cooling, transportation, water, and just everything all take much more effort/resources to produce in a solo venture like that. I’m not saying I don’t see the appeal, but the Earth could not (even remotely) support everyone living that way.

Net zero living looks a lot more like the Upper West Side than a cabin in the woods.

There's a reason NY is near the lowest per capita energy consumption for residential usage.

No idea of the situation there, but rural areas in our part of the world tap underground sources for water. It gets pumped and filtered on premise. Septic is a big tank with a field up front for dispersing fluids/liquids. Commenter below mentioned trash, but if you are applying some basic sustainable living techniques, the amount of trash produced should be minimal to none.

I don’t know this specific area, but some deserts you have to drill impractically deep to get to any ground water.