Ask an emergency manager what actually breaks first and the answer is never dramatic. It is water. A main breaks, a pump loses power, a treatment plant issues a boil-water notice, and within a day a normal household is standing in a store looking at empty shelves. Water is heavy, unglamorous, and almost free to store ahead of time, which is exactly why it belongs at the front of every plan on this site.
The Math: One Gallon, Per Person, Per Day
FEMA and the CDC both plan on one gallon per person per day for drinking and sanitation combined. Roughly half of that is drinking water for a resting adult in mild weather. Heat, physical labor, fever, vomiting or diarrhea, pregnancy, and nursing all push the real number up, sometimes sharply, so treat one gallon as the planning floor and store margin where you can. A household of four needs 12 gallons for the 72-hour floor and about 56 gallons for the two-week goal. That sounds like a lot until you price it: it is a few food-grade containers in a closet corner, filled from the tap.
Containers and Where the Water Lives
Store water in clean, food-grade containers that once held food or drink, or in purpose-made water containers with a spigot. Two-liter soda bottles, thoroughly washed, are a proven budget option. Never use a container that held chemicals, fuel, or anything non-food, and avoid milk jugs, which degrade and leak. Fill to the top, cap tightly, label with the date, and store in a cool, dark place, off bare concrete on wood or cardboard, away from fuel and cleaning chemicals whose vapors can migrate through plastic over time. Municipal tap water that was treated when it left the plant needs no additional bleach for storage in a clean container; well water should be disinfected first or boiled before drinking.
Treatment, in the Right Order
When water quality is in doubt, the order matters: settle and filter first, then disinfect. Let cloudy water stand, pour off the clear water, and pass it through a clean cloth, coffee filter, or a quality portable filter to remove sediment. Filtration improves clarity and taste; it is the disinfection step that kills pathogens. Boiling is the most effective method and needs no measuring: bring water to a rolling boil for 1 minute (3 minutes at elevations above 6,500 feet), then let it cool and store it covered. When fuel is short, use regular, unscented liquid household bleach, and read the concentration on your bottle, because the dose changes with it. For 6 percent sodium hypochlorite bleach, the CDC ratio is 8 drops per gallon of clear water, or 16 drops per gallon of cloudy water after filtering. For 8.25 percent bleach, it is 6 drops per gallon clear, or 12 drops per gallon cloudy. Stir, wait 30 minutes, and check: the water should carry a slight chlorine smell. If it does not, repeat the dose and wait 15 more minutes. Bleach loses strength with age and heat, so replace the bottle yearly and never use scented, color-safe, or splash-less formulas, and never mix bleach with ammonia or acids.
Rotation and the Second Source
Stored water does not spoil the way food does, but containers get damaged, seals weep, and forgotten caches stop being trustworthy. Rotate every six months: use the old water for plants, cleaning, and toilet flushing, wash the containers, and refill. Tie the rotation to something you already do twice a year, like the clock change. Then think past the containers. A standard water heater holds 30 to 50 gallons of potable water if you shut off the inlet before a contamination event reaches it. A bathtub bladder, filled when a storm is forecast, adds up to 100 gallons for sanitation and, if the bladder and water are clean, for treated drinking use. Rain barrels are for the garden and flushing only, never for drinking without full treatment. The households that come through a water emergency calmly are not the ones with the biggest cache. They are the ones who knew their numbers, their containers, and their second source before the notice ever arrived.