Portuguese Prepper

How much water do you really need for 72 hours vs 2 weeks?

The universal rule of thumb for emergency water storage is one gallon per person, per day. This covers drinking and very basic hygiene.
However, this math gets complicated quickly. While storing three gallons for a single person is easy, storing two weeks of water for a family of four involves managing over 450 pounds of liquid.

This guide breaks down the realistic storage requirements for short-term outages versus long-term survival, and what containers you need to handle the weight.

Tier 1: The 72-Hour Kit (Minimum)

For a standard 3-day power outage or storm, the math is simple. A family of four needs 12 gallons minimum.

You can achieve this easily with store-bought cases of water, but they leak over time. A better solution is a dedicated rigid container like a Jerry Can or WaterBrick, which holds 3.5 to 5 gallons per unit. Three of these in a closet solves the problem instantly.

Tier 2: The Two-Week Supply

For 14 days, a family of four needs 56 gallons. This is where “cases of water” fail—they take up too much floor space.

To store 55+ gallons efficiently, you have two options: a single 55-gallon blue barrel (requires a garage/basement) or a stack of interlocking WaterBricks (fits in a closet). If you live in an apartment, you likely cannot store this much volume and must rely on a WaterBob for the bathtub if a storm is approaching.

Tier 3: Indefinite Survival (Filtration)

You cannot store enough water for a year. Once your 2-week supply runs out, you must scavenge water from rain, lakes, or swimming pools.

At this point, storage matters less than filtration. You need a high-capacity filter (like a Berkey or ProOne) to make that scavenged water safe to drink.

Gear to solve the volume problem

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