Is a freshwater tank necessary if not traveling?

All I'm going to say is that the place I'm staying at for the winter has had to shut down their water system twice so far in the last few months.

Last year, the place I was at for the winter lost water pressure in the morning when the main line broke. My neighbor's wife was in the middle of a shower. I heard her yelling all the way over at my place. He didn't have any water in his tank. Not sure if he's still among the living or not.

I now keep 10 gallons in my tank.

Tim