Plan your water before the tap runs dry

Water is the one supply where running out is genuinely dangerous. The general baseline is one gallon per person per day — split between drinking and sanitation — and more in heat, for pregnant or nursing people, or for anyone sick. That number is a floor, not a plan. A real water plan covers how much you store, where you store it, how you keep it fresh, and what you do when the stored water runs out.

Calculate how much you actually need

Start with the one-gallon-per-person-per-day baseline and multiply by your household and the number of days you're planning for. A household of four planning for a week needs 28 gallons of water just for people. Add a half-gallon per day per pet for dogs and cats — and more for larger animals. If you live somewhere hot, or if anyone is pregnant, nursing, or ill, raise the per-person allowance. The CDC and FEMA both publish this baseline; it's not a guess.

That number covers drinking, cooking, and a minimum of hygiene. It does not cover flushing toilets, washing dishes generously, or showers. Those use far more water than people expect — a toilet flush is 1.6 to 3 gallons. Decide what your plan covers: do you store enough for full sanitation, or only for drinking and minimal handwashing, with a separate plan (like a bathtub fill at the first warning) for sanitation?

Use the water planner tool to get a household-specific number with adjustable allowances. It separates drinking and food-prep from other uses, and lets you add heat or activity factors. It's planning math, not a medical hydration prescription — but it's the right planning math, and it's the difference between 'I think we have enough' and 'I know we have enough for seven days.'

Plan for the scenarios you're likely to face. A short outage needs a few days of water; a hurricane or earthquake aftermath may need two weeks. If your water utility issues a boil advisory, you need water for drinking and cooking but your taps may still run for sanitation. If the water itself is off, you need it for everything. Know the difference and plan for the worst case you're realistically preparing for.

Don't forget that water is heavy — 8.3 pounds per gallon. 28 gallons is 230 pounds. Store it where the floor can hold it, not on high shelves, and where you can reach it. A container you can't lift or get to is not a plan. Think about where the water lives and how you'll get it from storage to use.

Store it so it stays safe

Store water in food-grade containers — never in containers that held anything but food or water, and never in milk-style jugs that don't seal or that degrade over time. Commercially bottled water is fine and has a long shelf life; refilled food-grade containers need cleaning and a date label. Store in a cool, dark, pest-free spot away from chemicals and gasoline — a garage shelf next to the gas can is not a good spot.

Rotate stored water every six months. Even sealed water can develop off-tastes from container leaching, and a forgotten jug with a slow leak is a mess you don't want during an outage. Mark each container with the fill date so rotation is obvious. When you rotate, empty it, rinse it, refill it, and re-date it. It's a ten-minute job twice a year.

If your tap water is treated (chlorinated), it can go straight into clean containers. If you're on a private well or storing rainwater, the storage and treatment story is different — see the dedicated water guide for collection and treatment details. The CDC and EPA have specific guidance on home water storage; the short version is: clean containers, cool storage, six-month rotation.

Consider container types by your situation. Small bottles are grab-and-go and easy to distribute. Large jugs (5–7 gallon) are efficient for storage but heavy and hard to pour. A 55-gallon drum is space-efficient but requires a pump. For most households, a mix of small bottles for drinking and a couple of large containers for cooking and sanitation is the practical setup. Don't overcommit to one type.

Store some water in your vehicle too, especially if you commute or travel in areas where you could be stranded. A gallon or two per person in the car, rotated seasonally (water in a hot car degrades faster), covers the stranded scenario. The vehicle readiness page covers this in more depth.

Know how to treat water if storage runs out

Stored water eventually runs out. Have a treatment method and understand its limits. Boiling for one minute (three at altitude) kills the pathogens that matter most for drinking water. Chemical treatment with unscented household bleach or water-purification tablets is a backup when boiling isn't possible. The EPA and CDC publish specific guidance on each method; the bleach ratio is about 8 drops per gallon of clear water, doubled for cloudy — but verify current guidance.

Filters remove some contaminants but not all. A backpacking filter handles bacteria and protozoa; only specific designs handle viruses, chemicals, or heavy metals. Know what your filter is rated for and what it isn't. A filter that says 'removes bacteria' does not remove chemicals from a spill, and a carbon filter that removes taste doesn't remove pathogens. Read the specifications, not the marketing.

The honest limitation: none of these turn floodwater or visibly contaminated water into something safe. If water is cloudy or has debris, filter or let it settle first, then treat. And no home method handles chemical contamination from a spill — that water isn't for treating, it's for avoiding. Know your local water advisory process and what a boil-water notice means.

Don't plan to improvise a water source you've never used. The first time you boil water over a camp stove or run a filter shouldn't be during an outage. Practice it once. The confidence is the point — and the surprise of 'this takes longer than I thought' or 'I don't have the right pot' is one you want to have before the power is out, not during.

Have a backup to the backup. Boiling is primary, chemical treatment is the backup, and a filter is for specific situations. If your plan is 'I have a filter' and nothing else, you have one method. If the filter fails, you're stuck. Two methods is a plan; one method is a hope. The water basics page is about building the redundancy that makes the plan real.

This is planning guidance, not emergency advice. In an emergency, call 911. See a mistake? Report it.

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