It covers the failure that arrives first, costs less than a tank of gas, and needs no maintenance beyond a calendar reminder.
Build the household kit →Emergency water storage is the least glamorous purchase in home resilience and the one with the best return, particularly on a private well where pressure dies the instant the grid does. The whole subject fits into four questions: how much, in what, where, and how often you swap it. Answer those honestly and you have covered the first three days of almost any outage for less than the price of a mid-range portable heater.
How Much: Start at a Gallon a Day
Ready.gov’s baseline is one gallon per person per day for drinking and sanitation, with more for hot climates, children, nursing mothers and anyone ill. That gallon is not just what you drink. It is drinking, cooking, teeth, hands, and the dishes you cannot skip.
What it does not cover is flushing, and on a well that is the volume that surprises people. A single pour-flush takes roughly a gallon and a half. Two adults, a normal day, and you are looking at more water going down the toilet than into the household. So plan drinking water at the gallon-per-person rate and treat flush water as a separate, non-potable pool: bathtub, rain barrels, pond, snowmelt. Nothing about it has to be clean.
| Household | 3 days | 2 weeks |
|---|---|---|
| 1 person | 3 gal | 14 gal |
| 2 people | 6 gal | 28 gal |
| 4 people | 12 gal | 56 gal |
| 4 + one dog | ~14 gal | ~65 gal |
Two weeks for a family of four is 56 gallons, which is about 470 pounds. Hold that number, because it decides where the water can live.
In What: Containers, Ranked by How They Fail
- Commercially bottled water. Sealed, dated, no preparation needed. Keep it in the original container and do not decant it into something else.
- Stackable 3 to 5 gallon jugs such as WaterBrick style containers. About 25 to 40 pounds each, which one adult can still carry, and they stack without crushing.
- Blue 55-gallon drums. Cheapest per gallon by a distance. Also 460 pounds when full, immovable, and useless without a siphon pump you remembered to buy.
- Reused soda bottles. Acceptable, food-grade, and free. Wash and sanitize before filling.
- Reused milk jugs. The one to avoid. Milk protein and sugar never fully wash out, and the plastic degrades and splits, usually while stacked on something you cared about.
To sanitize a container before filling, Ready.gov specifies one teaspoon of unscented liquid household chlorine bleach in a quart of water, swirled to touch every surface, then rinsed thoroughly. That is the whole procedure. It costs nothing and it is the difference between water you can drink in year two and water you cannot.
Where: The Floor Has an Opinion
Water weighs 8.34 pounds per gallon. Four 55-gallon drums in one corner of a basement is nearly 1,850 pounds in about nine square feet, and that is a conversation with the slab or the joists rather than a decorating choice. Spread the load, keep drums on a slab rather than a wood floor, and never stack drums on drums.
Beyond weight, a few siting rules do the real work:
- Cool and dark. Sunlight grows algae in translucent containers and heat accelerates plastic breakdown.
- Not on bare concrete for long-term plastic storage. Use a pallet or plywood sheet.
- Never where it can freeze solid. Frozen water expands, splits containers, and you find out in April.
- Split the stash across two locations if you can, so one burst pipe or one flooded corner does not take all of it.
An unheated garage in a northern winter is the classic mistake, and it fails at exactly the moment you were counting on it. If that is your only space, the same logic that protects your plumbing applies here, and it is worked through in how to keep pipes from freezing without heat.
How Often: The Rotation Question
Water does not spoil. Containers do, and so does whatever was in the water when you sealed it. Ready.gov’s guidance is that water you bottled yourself should be replaced every six months. Commercially bottled water carries its own date and generally lasts longer, though the plastic will eventually let taste through.
Six months is easy to schedule and easy to forget. Tie it to something you already do twice a year, like the clock change or the smoke alarm batteries, and empty the old water onto the garden rather than down the drain so the swap feels less wasteful.
Storage Is Not Treatment
Stored water is a fixed quantity. A filter is a rate. You want both, and they solve different problems: the stash covers days one to three with zero effort, and a filter turns pond, rain or questionable well water into something drinkable for as long as you keep pumping. Gravity units like a Berkey sit on a counter and need no power. A Sawyer or LifeStraw costs a fraction of that and fits in a drawer.
Safety: No filter is a blanket permission slip. Most remove bacteria and protozoa, not viruses, dissolved chemicals, nitrates or heavy metals. After flooding near a wellhead, EPA’s advice is to stop using the well entirely until a contractor has cleaned and disinfected it and you have pumped until clear.
What I Would Buy, In Order
Start with three days per person in stackable jugs, because they are the format you will actually carry up a basement stair by flashlight. Add a filter next, since it changes what counts as a water source. Only then consider a drum or a larger tank, and only if you have a slab to put it on and a pump to get it out. Working from the fast failures backwards, which is how we lay out what breaks first when the grid goes down, water is the first thing to go and the cheapest to fix. It should be the first thing you buy, well before the generator conversation in when your well loses power.
Frequently Asked Questions
How long can you store water for emergencies?
Water you bottled yourself should be replaced every six months. Commercially sealed bottles last considerably longer, limited by the plastic and the printed date rather than the water.
Can I store water in milk jugs?
Not for anything long term. Milk residue supports bacterial growth and the plastic is thin enough to split at the seams within a year or two.
How much water do I need for a family of four for two weeks?
About 56 gallons of drinking and sanitation water at the standard one gallon per person per day, plus a separate non-potable supply for flushing.
Do I need to add bleach to stored water?
Not if you start with treated water in a sanitized food-grade container. The bleach step is for cleaning the container, and separately for treating water of unknown quality.