Another thing to consider: some have mentioned having water to flush the toilet...that's well and good if you're on a septic system, but if you are on a municipal sewer system it requires pumping to keep it moving. Look around you and see if there are any houses at higher elevations and remember what rolls downhill. If you want to keep the house habitable, it might pay to block the toilets with plastic, rags, or whatever stopper you can come up with. It won't have to hold a lot of pressure, just enough that the 'artesian wells' spring up in another house(s) on your level. Of course sinks will be affected as well; the bathroom sinks with the overflow vent will probably need to be blocked at the trap while the kitchen can be closed with a less permanent measure so it can be used to determine the condition of the situation. Maybe on a sortie an empty place can be found where the cleanout trap can be opened to use their yard as a leech field and restore use to your plumbing.
Generators do make a lot of noise, now is the time to source a length of flexible exhaust pipe and weld fitting on it and the muffler so that it can be directed (ideally underground through a gopher tunnel) or some other makeshift silencing medium.