How much emergency water should I store?
Start with enough safe water for three days. If you have the room, build toward two weeks. You do not need a garage full of giant barrels to get started.
Hidden backup: water you may already have
A tank-style water heater can hold a major emergency reserve.
CDC lists water from the home's tap-water-heater tank as a possible emergency water source. A common tank may hold dozens of gallons. This means some households already have a substantial reserve they never count.
Important: this applies to the tank that supplies hot tap water, not a boiler or radiator/heating-system tank. If authorities say the public water supply may be contaminated, follow local guidance before using water from household plumbing. Know your heater's safe shutdown and draining procedure before an emergency.
That clear tank water can be a last-resort source.
CDC identifies water from the toilet tank as a possible source when it is clear and has not been chemically treated with products such as in-tank cleaners that change or treat the water.
Do not use toilet-bowl water as drinking water. And do not count toilet-tank water as a reason to skip stored drinking water. Think of it as a hidden reserve you should know exists.
Frozen water does two jobs.
Freeze suitable containers of safe water with room for expansion. They add thermal mass that helps the freezer stay cold during an outage, then become drinking water as they thaw.
Use every clean container before the tap becomes questionable.
If you have warning and the water supply is still confirmed safe, fill clean food-safe containers you already own. This is free temporary capacity. A bathtub bladder can add much more without requiring permanent storage space.
Choose the storage that fits your space
WaterBrick 3.5-gallon containers
One = 3.5 person-days. Four = 14 gallons, enough for 1 person for 2 weeks or about 4 people for 3 days at the 1-gallon baseline.
Why they make sense: rectangular, stackable and much easier to move than a giant tank. Individual filled containers are roughly 30 pounds of water rather than 50–60+ pounds.
Easy places to store them: closet floor, under sturdy shelving, along a pantry wall or other cool dark low space. Their rectangular shape wastes less space than round jugs.
Buy WaterBrick 4-pack on Amazon →See WaterBrick →Reliance Aqua-Tainer 7 gallon
One = 7 person-days, or a little more than the 3-day baseline for 2 people. Two = 14 gallons.
Why it makes sense: a lot of water in one reusable container with a spigot, without committing to permanent bulk storage.
Easy places to store it: bottom of a pantry or closet, utility room, basement or garage if temperatures are appropriate. Seven gallons of water alone weighs about 58 pounds, so store it low and where you will not have to move it often.
Buy Aqua-Tainer on Amazon →waterBOB bathtub bladder
Up to 100 gallons when filled. That is far beyond a 2-week baseline for a typical small household.
Why it makes sense: it stores compactly while empty, then turns a bathtub into a large sealed water reserve when a hurricane, ice storm or other forecast emergency gives you warning.
Easy places to store it: linen closet, bathroom cabinet or emergency-kit bin until needed.
The catch: this is a last-minute fill option, not your only reserve. You need warning and safe tap water still flowing when you fill it.
Buy waterBOB on Amazon →See waterBOB →55-gallon food-grade water barrel
55 gallons = about 55 person-days. For a family of four, that is almost 14 days at the 1-gallon baseline.
Why it makes sense: very efficient bulk storage when you have a permanent place for it.
Easy places to store it: suitable ground-level utility, basement or other cool protected area where it can stay permanently.
Know before buying: a full barrel approaches 460 pounds. Plan the location, filling and pump or siphon before filling it. This is generally not the apartment option.
Exactly how much does your household need?
| Household | 3 days | 7 days | 14 days |
|---|---|---|---|
| 1 person | 3 gal | 7 gal | 14 gal |
| 2 people | 6 gal | 14 gal | 28 gal |
| 4 people | 12 gal | 28 gal | 56 gal |
| 5 people | 15 gal | 35 gal | 70 gal |
If you have $0
Do not wait for special equipment. Before a forecast emergency, fill clean food-safe containers you already own. Use durable containers with tight lids and never reuse containers that held bleach, pesticides, fuel or other toxic chemicals.
Commercially bottled water is also a straightforward reserve. Keep it in its original sealed container and follow the manufacturer's date/storage instructions.
You can also freeze suitable water containers with room for expansion. They add cold mass to the freezer during an outage and become drinking water as they thaw.
How to store it safely
For water you fill yourself, use food-grade containers. CDC recommends labeling them as drinking water with the storage date, replacing self-filled water every 6 months, and keeping it cool, out of direct sunlight and away from gasoline, pesticides and other toxic substances.
Heavy water belongs low. Water weighs about 8.3 pounds per gallon. Avoid loading questionable shelves, and in apartments distribute larger reserves rather than concentrating enormous weight in one spot.
Want to fill a larger tank from a hose?
Show me hose-filter options
If the source is already potable municipal or well water, an inline hose filter can improve taste and reduce specific contaminants before storage. It does not magically turn unknown water into safe drinking water.
Camco TastePURE 40043: simple hose-connected filtration for already-potable fill water. See Camco →
Waterdrop RVS Inline: another compact hose option using activated carbon/KDF-type filtration for already-potable source water. See Waterdrop →
Clearsource Ultra Mini: a larger multi-stage system for people filling RV or larger storage systems who want broader filtration. See Clearsource →
Storage eventually runs out
Your complete water plan has three layers: stored safe water, another water source, and a way to treat questionable water. Get the stored-water layer handled first. Then add treatment so the plan does not end when the last container is empty.
See emergency water-treatment options →Why 1 gallon per person per day?
CDC uses at least 1 gallon per person per day for emergency drinking, cooking, brushing teeth and other limited uses, recommends keeping at least 3 days, and says to try for 2 weeks if possible. More may be needed for hot weather, pets, pregnancy or illness.
CDC emergency water storage guidance →