So right now I am stuck in a condo and my wife and I have talked about getting our food storage up. Right now we have enough water for about a week and enough food for about two weeks. Our goal is to get a year's worth of food storage. My question is one of how much water I should have on hand. If I figure 1.5 gallons of water per day and our soon to be four family members I will need six gallons per day. That would translate into 27 7-gallon water containers. I have concerns about storage for all this plus the food. How much water do should you have on hand? I have identified about four sources of water within a mile but all would require filtering/purifying based on their proximity to roads and such. So given my constraints with space how many days should I keep on hand versus planning to get water and purify it?