I'm in a city, my home on a hillside with a slope that goes down in my back yard. The other street behind my home is at lower elevation. An old timer in the neighborhood told me water used to flow at the bottom as a creek from upper hills, the city laid drainage pipe and covered it over. If the tap water stops flowing, I'm drilling into that drainage pipe. I suspect a lot of creeks run underground beneath many neighborhoods in many hilly cities and towns.
You should learn how to ‘witch’ water, meaning find underground springs that are close to the surface.
Forget the forked stick thing, there are plenty of online sites that will show you how using coat hanger wire. It really does work, but so far science can’t explain exactly why it works.
An old farmer showed me how to do it and I was amazed. There were about 10 of us from the sportsmans club there, all tried it and it worked every time.
He found a spring up on a hill in a friends yard. My buddy got the backhoe out and dug down about 8 feet and water gushed out of a spring. He had a pond dug in his yard after that.