Water is the most important element when stocking up for a hurricane or other disaster. The recommended quantity is to store 3 gallons of water per person for each day the disaster will presumably last. But sometimes, disasters can last longer than anticipated, so knowing how to purify water from an alternative water source could potentially save your life. Since your source could be a river, lake or other, the water will not only taste and smell bad, but could be harmful because of the microorganisms and pollutants in it. This is why you will need to purify it before consuming it. It is always a better idea to get water from moving sources if you can.