Milk containers have a short shelf life. Plastic soft drink containers work well. Don't use breakable containers. Five -gallon water jugs for camping are available and they are very sturdy. New plastic garbage cans could be useful for storage.
Most cities have about a three- day supply of water, but when that is gone, they depend on pumps.
Water could be in short supply if power is down for a few days. Water should be treated if it is to be stored for any length of time. Sodium hypochlorite must be the only active ingredient. Mix 8 drops of bleach into one gallon of water. If water is cloudy, use 16 drops.