How to Properly Build a Drinking Water Reserve for a Power or Water Outage

Power and water outages in Odesa aren’t a hypothetical scenario — they’re a very real part of life in recent years. And when they happen, the first thing you need is water. Not “just in case, in the garage,” but a properly organized reserve you can actually reach when the moment comes.

There won’t be any general talk about why you need a reserve here. Let’s get straight to the point: how many liters, in what container, how long to store, and what to consider if you live in an apartment, work in an office, or have young children.

How much water you need: let’s calculate honestly

Let’s start with a baseline figure. The commonly accepted recommendation for an emergency reserve is about 3 liters per person per day. That’s not “for drinking” — it’s everything together: drinking, cooking and minimal hygiene.

Let’s calculate with examples:

• One person for 3 days — about 9 liters. That’s roughly half a standard bottle.
• A family of four for 3 days — about 36 liters. That’s already two standard 18.9-liter bottles.
• An office of 10 people for 2 days — about 60 liters. Three or four bottles.

Build in a little more than the calculation says. Better to have some left over than not enough. And remember: the reserve is about drinking water. For technical needs — washing, watering — tap water or water stored in buckets will do, as long as you don’t drink it.

What to store it in

The container is the second most important question after quantity. It determines how long the reserve lasts and how safe it is.

What works:

• Factory-bottled water — the most reliable option. It’s already sealed in airtight packaging with a known shelf life.
• Tightly sealed containers — if you fill them yourself, use clean containers with an airtight lid, preferably glass or food-grade plastic.

What to avoid: storing water in containers that previously held other drinks and still smell, in bottles left in the sun or heat, and especially in containers not meant for food. We’ve written separately about how to store water properly and what conditions extend its shelf life: «How to properly store drinking water».

How long to store and when to refresh

Water has a shelf life, and it’s not infinite. For bottled water it’s usually printed on the label — and that’s not marketing, it’s a real recommendation.

The rule is simple: keep an eye on the date and refresh your reserve in advance, not when it’s already gone bad. The best approach is “use and replace”: the reserve shouldn’t sit as dead weight. Use the older bottles in your daily life and put fresh ones in their place.

Every few months, it’s worth checking the dates and replacing water whose shelf life is running out. That takes five minutes, but at least you won’t end up with a reserve you can’t drink when you need it.

Separately for apartments

In an apartment, the main problem is space. There’s nowhere to store many bottles, so the approach needs to be compact.

What I’d suggest:

• Keep a 2–3 day reserve — that’s enough to get through a typical outage.
• Use vertical space: mezzanines, lower shelves, the pantry.
• Keep bottles away from radiators and windows — heat shortens shelf life.
• Don’t forget the technical reserve: buckets or large containers of water for household needs.

Separately for offices

In an office, the reserve isn’t so much about survival as about keeping work from stopping. People come in and want to drink, and if there’s no water, that’s a problem right away.

What to consider:

• Calculate the reserve based on the number of employees who actually come to the office.
• Keep one or two spare bottles on top of your regular consumption.
• Assign someone responsible for keeping track of dates and refilling.
• Remember: during a power outage the cooler may not work, so the reserve should be in bottles you can pour from by hand.

By the way, if you’re thinking about regular office delivery, we have a separate breakdown of how to set it up cost-effectively: «Cascade water delivery for offices: 5 undeniable benefits».

Separately for families with children

With children, the reserve is a different story. The norms for a child differ, and you need to approach the calculation more carefully.

What matters:

• For young children, calculate water according to their age — infants and toddlers need more fluid relative to their weight.
• If you use formula or boil water for your child, factor that into the reserve volume.
• Keep the reserve somewhere out of a child’s reach, but where adults can get to it easily.
• Don’t skimp on quality: water for children should be especially clean.

A quick checklist

1. Calculate from 3 liters per person per day and build in extra.
2. Store in factory-bottled water or airtight food-grade containers.
3. Keep bottles away from sun, heat and radiators.
4. Track dates and refresh the reserve using the “use and replace” approach.
5. For an apartment — a compact 2–3 day reserve; for an office — with extra for employees; for a family with children — accounting for their norms.
6. Don’t forget the technical water reserve for household needs.

How we can help

We, Cascade, produce and deliver purified drinking water in Odesa and the region. If you want to build a reserve you can store and refresh with confidence, place an order. We’ll bring water to your home or office, and you’ll know it’s within reach when you need it.

And if you’d like to dig deeper into the topic, read our article about building a water reserve without the rush: «Water just in case: building your reserve without the rush».