Storing drinking water at home: how much and how?

Reading time: ~11 minutes

What does storing drinking water actually mean?

Storing drinking water at home means setting aside a fixed amount of water that you can use when no water comes out of the tap. Not the jug in the fridge for tonight, but a supply that can stand untouched for months and still be safe when you need it.

The difference from simply keeping water comes down to two things: the amount is calculated and the moment of refreshing is fixed. Without those two it is not a supply but a few bottles at the back of the cupboard that nobody knows the age of any more.

The Dutch government places this in a broader story in its campaign Denk vooruit, the national preparedness campaign: water is one part of an emergency kit that you check every six months. That half-yearly rhythm is not coincidentally the same as the rhythm at which you refresh your water. You do it in one go.

How much drinking water should you store at home?

The figure everything rests on is 3 litres per person per day. According to Vitens, a Dutch drinking water company, that means you need at least 9 litres per person for three days: 6 litres for drinking and 3 litres for preparing food. For a family of four that comes to 36 litres.

Why three days? Because an emergency kit is meant for the first 72 hours, the period in which the emergency services, the municipality and the national government have to be able to tackle the crisis and you have to be able to look after yourself. After that, assistance gets under way.

That last row is almost always forgotten. Brabant Water, a Dutch drinking water company, advises setting aside about half a litre per day per animal for pets. With two cats and a dog that is one and a half litres a day extra, and then a family of four is already at well over 40 litres.

Note that this is an emergency amount, not a daily requirement. How much you normally drink is higher and depends on your weight, your activity and the weather. If you want to work that out, take a look at how much water you need per day. The 3 litres in this article is the minimum to get through three days, not the comfort level.

Why your own water supply makes sense

The Netherlands has one of the most reliable drinking water supplies in the world. According to Brabant Water, drinking water companies can keep delivering water for ten days without power, thanks to their own power supply and stocks of fuel and treatment agents. The chance that you will need your supply is therefore small.

But small is not zero, and the consequences are immediate. Without tap water you cannot only not drink: your toilet will not flush, you cannot shower, and the washing machine, dishwasher and coffee maker do nothing. You notice that within a few hours.

In the event of a prolonged outage, your drinking water company arranges emergency drinking water. If it lasts longer than 24 hours without water, you get 3 litres per person per day at a distribution point nearby, to which you bring your own bottles or a jerrycan. It is precisely those first 24 hours that your supply has to bridge.

There is a second reason, which is less dramatic and happens more often: planned pipework or a boil water advisory in your neighbourhood. There is water then, but not water you simply drink. What you do in that case is in our article on what to do when there is no tap water.

Buying bottled water or storing tap water yourself?

Both are fine, says Drinkwaterplatform, as long as you have something in stock. They differ in effort and in cost.

Pre-packaged bottled water

According to Vitens, unopened bottled water often stays good for years. You buy it, put it away and hardly look at it again. The price is the drawback: bottled water quickly costs €0.40 to €1.00 per litre. For 36 litres you are then paying €15.00 to €36.00, every time you renew the supply.

Storing tap water yourself

Dutch tap water is of excellent quality and costs about one and a half euros per cubic metre, so a few cents for your entire supply. What it costs is attention: clean bottles, clean hands and refreshing every six months. If you want to know exactly what a cubic metre of water costs in your region, work it out in our article on what a cubic metre of water costs.

How to store tap water: the step-by-step plan

Vitens describes seven steps. Together they take less than a quarter of an hour and they are not optional: each step removes one route of contamination.

1. Choose tightly sealable bottles: bottles or jerrycans with a screw cap, so that no dirt or bacteria reach the water.
2. Wash your hands: clean hands before you start reduce the chance of contamination.
3. Rinse the bottles out: rinse them first with clean tap water.
4. Fill to the brim: completely full, so that as little air as possible sits with the water. Air is what makes water age faster.
5. Seal immediately: cap on firmly as soon as the bottle is full, not an hour later.
6. Write the date on the bottle: without a date you will not know in five months whether it is four or fourteen months old.
7. Store cool and dark: a pantry or the cellar. Light and warmth give algae and bacteria a chance.

Repeat the whole thing every six months. Put it in your calendar at two fixed moments, for example when the clocks change, and then you do not have to think about it any further. You do not throw the old water away but use it for the plants or the washing machine.

Where it usually goes wrong

At PureFilter we see that customers who start an emergency supply almost always come unstuck on the same four things.

Reused juice or milk bottles

A bottle that has held sugar or protein will not become sterile by rinsing. A thin film always stays behind that feeds bacteria. Only use bottles that have held water or soft drinks, or buy clean jerrycans.

Half-filled bottles

The air above the water contains oxygen and microbes. The more air, the faster the taste changes and the sooner something can grow. Filling to the brim costs nothing and gains months of shelf life.

Storage in the shed or the garage

It gets too warm there in summer and it stands in too much light. The cellar, a north-facing cupboard or the bottom shelf of a pantry are better. A garage that freezes is just as bad, by the way: freezing water expands and makes bottles burst.

Drinking emergency water unboiled

If you collect water at a distribution point during an outage, that water itself is just as safe as ordinary drinking water. Your own jerrycan may not be. Brabant Water advises boiling the water for three minutes to be on the safe side and then letting it cool. If you cannot boil, use the cleanest bottle possible, store it cool and dark, and preferably drink it within 24 hours.

How long tap water stays good outside an emergency is a separate question with a different answer. We deal with that in our article on how long you can keep tap water, including the difference between a jug in the fridge and a bottle in the cupboard.

The three approaches side by side

The bottom rows are where the choice really lies. With bottled water you store dozens of empty bottles every six months. With tap water the bottle is reusable and it is only about what you pour into it.

What a water filter does and does not do for your supply

Honesty is in order here, because on this point many web shops promise too much.

What a fixed filter does not do

An under-sink water filter sits on your cold water pipe and works on water pressure. If nothing comes out of the tap, the filter does nothing either. A fixed filter is therefore not a solution during an outage, and anyone who suggests otherwise is selling you a story. Which type of filter does work without mains pressure and which does not is set out in our overview of which type of water filter works without water pressure and which does not. If you are looking specifically for a portable solution for a backpack, take a look at what you need in an emergency kit.

What a fixed filter does do

It determines the quality of the water you pour into your bottles before the outage. That is not nothing, because a supply is exactly as good as the water you fill it with. The PureFilter Mineral+ removes more than 100 contaminants in five stages, including PFAS, microplastics, heavy metals, nitrates, medicine residues and taste compounds, and is NSF 42, 53, 61 and 372 certified. As a final step, Swedish Mineral Rock™ adds calcium, magnesium and potassium back, so that after months in the cupboard the water tastes less flat than water you poured in unfiltered.

In practice what counts most is that you do not have to do anything at the moment itself. You fill your jerrycans at the filter that sits on your cold water pipe and you are done, without refilling jugs or waiting. The unit costs €149.00 including the first filter, and installation takes 5 to 10 minutes: you do not need a plumber and you use one pair of water pump pliers. You change the cartridge later with the key that comes with it. The full procedure is in our guide to installing a water filter.

Which approach suits your household?

Three situations, three pieces of advice.

You want to think about it as little as possible. Buy 36 litres of bottled water, put it in the cellar and note the best-before date in your calendar. Done. You pay more per litre, but you have settled the matter in one shopping trip.

You mainly drink tap water and do not want to lug bottles around. Buy two 20-litre jerrycans, fill them according to the step-by-step plan above and set two half-yearly reminders. This is the cheapest route and for most households the best.

You already find the taste of your tap water mediocre. Then a supply is not going to improve that, because storing never makes water nicer. Start at the source. Under our filters for everyday drinking water you will find what fits under your sink, and the replacement filter costs €65.00 for one cartridge or €115.00 for the duo of two. That is less than one cent per litre, compared with €0.40 to €1.00 for a litre of bottled water. If you would rather not think about it, the Filterplan sends it automatically and on time for €48.00 for 1 to 3 people or €86.00 for 4 to 6 people.

With 1 to 3 people a cartridge lasts about twelve months, with 4 to 6 people about six months. That is roughly the same rhythm as refreshing your supply, so you can combine both jobs.

Frequently asked questions

Conclusion

Storing drinking water at home is simpler than it seems: 3 litres per person per day, for three days, in clean bottles filled to the brim that you refresh every six months. For a family of four that is 36 litres and a quarter of an hour of work, twice a year. Bottled water or tap water makes no difference for safety, as long as you have something ready.

What does matter is the quality of what goes in. A supply only preserves, it never improves. Anyone who filters their tap water first stores water without more than 100 contaminants and with minerals that keep the taste bearable after months. That is where the PureFilter Mineral+ does its work: not during the outage, but on all the ordinary days before it.