When you say you have water shut offs without warning, is it completely gone, or do you notice a drop in water pressure until it's gone? Like AquaHull, I too use 1 gallon jugs for drinking water. Don't forget your hot water heater. It has 30 to 50 gallons of drinking water. Just open a faucet in the kitchen sink and open the bottom drain spigot on the water heater. The first water coming out will probably be rusty and if you want you filter it or use if for flushing the toilet. If you have some type of warning (lowering water pressure), fill your bathtub ASAP. I'd get one of those cheap plastic drop clothes and line the bath tub to prevent leakage down the drain. For flushing, you can fill garbage cans with a new plastic bag in it. I keep a few contractor giant size bags just for this purpose. You could also use kiddie pools to store water.