Obtaining running water was the first thing we did but it consisted of hiring a well witcher, drilling for water, putting a well in, putting in a pressure tank and piping to the house. It was a major expense. We had gray water for a few years, but eventually had to put in a septic system when we ditched the outhouse and installed a toilet.
Nowadays a professional hydrologist is who you'd contract for the task. They will do a geologic survey and fracture trace analysis using data from satellite imagery, the USGS and related state agencies in order to identify fissures within the underground rock formations that are most likely to hold a suitably sized pocket of water with good recovery. Then they might conduct electrical resistivity tomography to directly measure and image the density of subsurface material to identify water pockets and narrow down good drilling spots. It's a far cry from the sort of thing that might be characterized as dowsing.
I've also had experience installing a catch box (there's another term for it that escapes me right now) in a creek and running miles of pipe always with a slow decent to gravity feed several holding tanks. A word of warning, bears are curious about the sound of running water through pvc pipe, so bury that pipe...
For sure taxes still need to be paid... do you have a spare room? Could you AirBnB to supplement your income? Could you reduce your utilities by switching up some stuff in your house? Perhaps it would be cheaper for a gas stove than electric? Could you put solar panels on your roof to sell electricity back to the grid? Could you get a bike and ride more places to use less gas? Would having septic save money on waste? Could you hang dry your laundry instead of using a dryer?
Not saying that all or any of those are feasible for anyone/everyone, just offering some solutions that many people overlook when they think they're stuck and unable to reduce their costs any further and these things can be switched up without changing your lifestyle much/any. Some of them have a (in some cases large) up front cost, but then your monthly expenses can be reduced significantly which reduces your longer term income needs.
...and I don't know how you lived without running water, that's something I just can't give up, along with my washer and dishwasher.