Some people already HAVE large storage containers and don't realize or remember them. We're on a well and have the 'aerator' tank. It generally holds 250 gallons. If a hurricane is coming then I hold the float switch up so it fills the tank a lot more. It is outside so I do risk 'losing' it if it gets compromised but we have redundancy. We use that H20 for flushing toilets, washing etc.

Don't forget the water heater....IIRC 40-80 gallons depending on the size of it......

We also have 3 aquatainers (getting more) and in the 'off season' (for hurricanes) we have at least 5 cases of bottled drinking water. I've found that Wwashing the aquatiners and rinsing them well enough to drink from takes A LOT of time and diligence so we just go with bottled for drinking. We use it on a daily basis so it is constantly rotated.