In a regional disaster, your water system may fail before anything else. Pipes crack. Pumping stations lose power. Treatment facilities go offline. Contamination enters systems that normally deliver safe water. For most Pacific Northwest households, the municipal water supply is so reliable it’s invisible — until it isn’t.
The standard preparedness recommendation is one gallon of water per person per day, for at least three days. That’s a floor, not a ceiling. In a real extended regional emergency — a significant Cascadia earthquake — water infrastructure can take days to weeks to restore. The households who weather that comfortably are the ones who invested in more than three days of storage.
Here’s how to do it practically.
How Much Water Do You Actually Need?
The one-gallon-per-person-per-day figure covers drinking and minimal sanitation. It does not cover cooking, significant sanitation, or any medical needs. A more realistic planning figure for comfort:
- Drinking: 0.5 gallons per person per day (minimum), more in hot weather or physical activity
- Food preparation: 0.25–0.5 gallons per person per day
- Basic hygiene and sanitation: 0.5–1 gallon per person per day
Total: 1.5–2 gallons per person per day for basic comfort. For a family of four, a two-week supply at this rate is 84–112 gallons. That’s a significant storage commitment — but it’s achievable and worth planning toward.
Start with three days (12 gallons for a family of four). Build from there.
What Containers to Use
Commercial Bottled Water
The simplest starting point. It’s pre-sterilized, sealed, and has a two-year shelf life. Downside: it’s expensive at scale and generates significant plastic waste. Good for the first phase of building your supply; less practical as your primary long-term storage strategy.
WaterBOB or Bathtub Bladder
A WaterBOB is a large plastic bladder (100 gallons) that fits in a standard bathtub and can be filled from the tap before or immediately after an emergency. It costs about $30 and stores flat until needed. The limitation: you need advance warning to fill it, and once filled, it’s not portable. It’s a useful supplemental option, not a primary storage solution.
5-Gallon Water Jugs (Food-Grade Plastic)
The practical workhorse of home water storage. Blue food-grade 5-gallon HDPE containers are widely available at outdoor and preparedness stores for $8–15. Fill them from the tap, store in a cool dark location, and rotate every 6–12 months. Manageable to move, efficient use of space, and economical at scale.
55-Gallon Barrels
For households with storage space, 55-gallon food-grade barrels provide the most efficient long-term storage per dollar. A barrel fully filled weighs approximately 460 lbs — it is not movable once filled, so placement matters. A hand pump or siphon is needed to access the water. Best for households with a garage, basement, or stable outbuilding.
Where to Store It
Water storage works best in a location that is:
- Cool: Heat accelerates degradation of plastic containers and can affect water quality. Avoid areas that get hot (like an uninsulated garage in summer).
- Dark: Light promotes algae growth. Opaque containers or a dark location is preferable.
- Away from chemicals: Water containers can absorb fumes from fuel, cleaning products, and pesticides stored nearby. Keep your water storage away from these.
- On a stable surface: A significant earthquake can topple unsecured containers. Secure or brace large containers if possible.
Rotation: The Part People Skip
Tap water stored in sealed food-grade containers is typically safe for 6–12 months in ideal conditions, and many sources suggest up to five years for commercially sealed containers. That said, rotation is good practice — and the twice-annual clock-change reminder works well here.
A simple rotation system:
- Label containers with the fill date when you store them
- Store new containers behind or under old ones, so you use the oldest first
- When rotating, use the old water for gardening, cleaning, or just pour it out — don’t overthink it
- Refill and relabel before putting the container back
Alternative Water Sources in an Emergency
If your stored supply runs out, there are additional sources worth knowing:
- Water heater tank: A standard water heater tank holds 30–50 gallons of water that remains potable for some time after the tap goes out. Shut the cold inlet valve, attach a hose to the drain valve, and drain from the bottom. Boil or treat if uncertain about quality.
- Toilet tank (not bowl): The tank behind the toilet (not the bowl) contains clean water — typically 1.5–3 gallons. Treatable in an emergency.
- Rainwater: The Pacific Northwest is not short on rain. A food-grade collection barrel under a downspout can supplement your supply. Treat collected rainwater before drinking.
Water Treatment Options
- Boiling: The most reliable method. A rolling boil for one minute (three minutes above 6,500 feet elevation) kills pathogens. Requires fuel — factor this into your stove fuel storage.
- Bleach: Unscented household bleach (6–8.25% sodium hypochlorite): 8 drops per gallon, stir and let stand 30 minutes. Good for treating questionable water sources.
- Filtration: A quality gravity filter (Berkey, Sawyer) removes most biological contaminants and is useful for treating surface water. Not a substitute for boiling when dealing with unknown chemical contamination.
- Water purification tablets: Lightweight and portable. Keep some in your go-bag and car kit.
If you have questions about water storage for specific situations — a small apartment, a large family, someone with dietary restrictions on water intake — drop them in the comments. And if you’re just getting started with preparedness, our free resource page has a quick-start guide that covers water alongside the other basics.