Emergency Water for a 3-Day Outage: How Much to Store + Easy Storage Plan
ZacharyWilliam
Power Outage Prep· 3-day (72-hour) emergency water plan
If the power goes out, water can become a problem faster than most people expect—especially if you live in an apartment, rely on an electric well pump, or your area issues a boil-water advisory after storms. Here’s a practical 72-hour plan you can actually follow, plus a printable checklist.
A widely used planning baseline is 1 gallon of water per person per day for drinking and basic sanitation. For a 3-day outage, that’s 3 gallons per person.
Quick rule you can remember:
People × 3 days × 1 gallon = your minimum 72-hour supply
Add extra if you have babies (formula), anyone sick, hot weather, or pets.
What “water needs” really include (not just drinking)
In real outages, people run short on water because they only plan for drinking. A better mental model is: drink + cook + hygiene + cleanup.
Use water for
Drinking and coffee/tea
Quick meals (oatmeal, soup, freeze-dried foods)
Brushing teeth, hand cleaning
Basic dish cleaning (minimal)
Plan around your home
Apartments: water pressure can drop if building pumps lose power.
Wells: no electricity often means no running water.
Storm/flood areas: tap water can be restricted (boil-water advisories).
Small move, big win: keep a dedicated “hand hygiene” setup (wipes + a small pour bottle) so you don’t burn through your drinking supply doing basic cleanup.
When the outage hits: a realistic daily water budget
A plan works better when it tells you what to do on a tired day, not just what to buy. Here’s an easy “daily budget” that keeps you from blowing through your supply early.
Daily bucket
Target per person
What it covers
How to make it last
Drink
About half your daily share
Water + simple beverages
Use cups/bottles you can track
Cook
Small portion
Quick meals, minimal dishes
Choose low-water foods; use paper plates if needed
Hygiene
Small portion
Teeth, hands, basic cleanup
Use wipes + a pour bottle to avoid waste
Buffer
Whatever’s left
Unexpected needs
Don’t spend it early
One practical pairing: food + water
If you’re trying to save refrigerated food, you’ll likely cook less (and use less water). If you’re cooking more shelf-stable foods, budget extra water. Use the fridge/freezer rules as your decision guide.
Storing “some water” without a number. You only discover it’s not enough on day two.
Putting water next to chemicals. Some vapors can permeate plastic over time.
Forgetting the opener problem. If your plan uses canned food, you need a manual can opener (and a bit of water to clean up).
Assuming the tap will stay safe. After storms, advisories can happen—plan for your stored water to be the default.
Ignoring wells/building pumps. If your water needs electricity, your “water plan” becomes a “power plan.”
Where backup power fits (light, practical)
This article is about water, but here’s the honest overlap: many homes “lose water” because they lose power. If you rely on an electric well pump or your building uses electric booster pumps, water storage is your first layer— and backup power can be your second.
Use backup power for outcomes, not comfort:
Keep communications on (phones + Wi-Fi) so you can receive alerts and updates.
If your water access depends on electricity, plan that load carefully (start with “what to run first”).
For solar recharge planning, avoid unsafe input setups (voltage limits matter).
How much water should I store per person for a 3-day power outage?
A simple minimum baseline is 1 gallon per person per day. For 72 hours, that’s 3 gallons per person. Add extra for hot weather, babies (formula needs), illness, and pets.
Do I need extra water for pets?
Yes. Add a buffer for each pet so you’re not borrowing from your drinking supply. If your pet eats dry food, plan a little extra water for feeding and cleanup.
How long can I store emergency water?
For commercially bottled water, follow the printed date. For home-filled containers, a practical refresh schedule is about every 6 months, plus anytime the container looks damaged or has been stored in heat.
Can I use water from my hot water heater during an outage?
In many homes, the water heater tank can provide additional water in an emergency. Treat it as a backup source and use good judgment on cleanliness. If you’re unsure about safety, use stored water first.
What if there’s a boil-water advisory or flooding?
Assume tap water may not be safe and switch to stored water for drinking and brushing teeth. Follow local guidance for boiling or disinfecting water before using it.
Do I need to disinfect stored water?
Sealed bottled water does not need treatment. For home-filled water, use clean food-grade containers and refresh on schedule. If water safety is in doubt, disinfect before drinking.
Sources & further reading
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