When you plan water storage, your first consideration should be how much do I need. For just minimum survival, you need to plan on one gallon a day per person. Today you are using in the neighborhood of 180 gallons a day, per person.
What kind of water sources would you have available if the water system in your area failed completely? Do you know where all the water sources in your area are? This should include rivers, streams, lakes, ponds and wells. These are all the obvious sources but what about the little known ones, the abandoned wells, sprinkler systems in high rises (be careful with these, some contain an antifreeze) large apartments or other big buildings have a lot of water in their plumbing systems. Make a survey of the possible water sources in your neighborhood.
What type terrain do you live in urban or rural, desert, mountains or plains. If you live in Florida, your considerations are totally different than if you live in southern Arizona. Plan on how to take advantage of the available water in your area. Make sure you have the chemicals or filters to make it potable.
However regardless of the available outside water sources, you need to store enough for two to three weeks. This is in case you are forced to stay inside your residence. This could be the result of quarantine, nuclear warfare, biological attacks, or an accidental release of radiation.
Tomorrow I will cover different ways to store water and its shelf life.