How Long Can You Store Water?

Keeping a sizable supply of clean drinking water on hand is one of the most essential preps that you can put into place for disaster prep and general preparedness. Preppers need fresh water for drinking as well as cooking, and any of us can only go a few days at most with absolutely no water to drink.

the top of a blue rain barrel filled with water
the top of a blue rain barrel filled with water

Accordingly, it is far from uncommon to find proponents of the personal readiness lifestyle stashing huge quantities of bottled or jugged water in their homes, or even investing in tanks and barrels that can hold dozens or hundreds of gallons. But one consideration escapes some of these dedicated preppers.

How long can this water be stored safely? Does it ever go bad?

Clean, pure water can be stored for quite a long time, but its shelf life varies. Water that is stored in a user supplied barrel or other large vessel will be more vulnerable to contamination by algae and bacteria than factory bottled water.

Even factory prepared and sealed water will over time degrade and lose volume due to evaporation and the leaching of chemicals from its container.

So long as you are storing water correctly and taking basic steps to keep it fresh and safe, your water will keep for a very long time although the taste and drink ability will steadily degrade.

There is much more to consider when it comes to long-term water storage, as you might expect, and we have provided you with more information just below.

Does bottled water go bad?

Contrary to the prognostications of butterfly-chasers who are missing the forest for the trees, water that is factory prepared, be it in bottles, jugs or any other container, does not have a proper expiration date even though the bottle might be marked with an expiration, sell-by or best-by date.

This of course begs the question, if that is true why is it marked with the date in the first place?

The answer is simple: certain states or even certain localities might mandate any consumable good that is sold in their domain be marked with some sort of freshness or sell-by date. It could be embossed in the plastic of the bottle, printed on the cap or written on the label.

It doesn’t matter where or how it is marked; it is just mandated that it be there and that means manufacturers, and an effort to save a tiny bit of money on packaging and processing, will simply print that date on every single bottle of water they sell.

However, it should be noted that just because water does not have an expiration date in reality, the water might not taste good after it is stored for a long period of time.

That onset of offensive taste or odor might take place before the sell-by date on the bottle or it might take place after. More on that in a minute.

When Good Water Goes Bad

Properly prepared and packaged factory produced bottled water will likely remain safe as long as the water lasts and the seals on the package remain intact. However, preppers are reminded that water is quite the solvent, and over time will likely leach various chemicals from its packaging.

Studies have shown that this leaching, though rarely dangerous, will significantly impact the taste of water and not for the better.

Note that just because your long-term storage bottled water tastes bad or funky it does not mean it is unsafe to drink.

You should also consider the notion that crisp, clear water sourced from a pristine natural lake or stream could also be terribly contaminated with pathogens on the microscopic level, so keep your priorities in order!

Also keep in mind that all natural sources, untreated, are far more likely to host algae growth when exposed to direct sunlight,

So, if you crack open a bottle or jug of water that has been sitting on the rack for quite a while and it has a slightly burnt, coppery or decidedly plastic note to the taste, know that it is probably just fine to drink even if it makes you crinkle your nose.

How About Water that Has a Broken Seal or was Never Sealed in the First Place?

Water that is not totally pure and has not been sealed is a different story, as is pure water that is placed in a container that is anything but.

Water is often host to all sorts of microscopic life, including bacteria, viruses and algae. When these tiny life forms are present they will begin to multiply if conditions are right.

A great way to create the aforementioned right conditions is to open a sealed container, drink from it, then recap it and put it back. The human mouth is a hideous hotbed of microscopic life, life that is now swarming through the water you just quaffed.

The bottom line is that any water you store that has not been purified and sealed inside a sterilized container should be consumed within a week or two at the most unless you want to risk serious colonies of microscopic life taking it over. This includes tap water and well water.

The longer you wait the more microscopic critters you’ll have to deal with, and quite a few of them can make you terribly sick.

So How Long Will My Water Last before Going Bad?

Determining how long your water will last in storage it’s sort of a function between where the water was sourced from, and what kind of container it is stored in.

For instance, tap water that is kept in an open container will easily start to go bad within a couple of days, with a bad being defined as the reproduction of harmful bacteria and other pathogens that can make you sick.

Take that same water and filter it, storing it in a clean, tightly closing container and you might get a week or perhaps two out of it.

Take it a step further and filter the water, then boil it, before storing it in a clean, special purpose container and you might get several of months out of it without any need of a rotation or further treatment.

But your best bet for long term storage is going to be factory produced bottled water, and distilled water in particular.

Kept in good conditions this water will easily last a year and probably closer to two years before there is any concern about treatment or other problems.

Use the Right Storage Containers

As mentioned above, storing your water in the proper containers, and the right environment, is critical for maximizing shelf life all other factors notwithstanding.

You can use almost any kind of container in a pinch, but if you need emergency water storage right now your best bet is going to be clean, thoroughly washed and disinfected glass or plastic containers with tightly closing lids or caps.

These are recommended by both FEMA and the CDC for impromptu, emergency water storage. But for a purpose driven long-term water storage plan, you should try to choose a food-grade container, and one designed for storing water in particular.

Containers of this type are designed to minimize the leaching of any harmful chemicals into the water, and also to withstand degradation from the water itself.

Containers for this purpose come in all sizes, shapes and applications are usually easily identified by the markings “food grade” or “H2O.”

What’s the Deal with Storing Water in Large Containers?

Storing water in larger vessels, like a 55-gallon water barrel or even multi-hundred gallon tanks complicates things somewhat for preppers.

Unlike those big bottled water factories, you don’t have the high-tech equipment necessary to purify huge amounts of water quickly on hand at your beck and call. That means you’ll have two choices when it comes to the water you place into storage.

You may either slowly and laboriously filter or otherwise purify it in order to get as much storage life out of it as possible or you can take your water as you find it and pour it straight into your containers.

There’s also an additional complication in assuring that your containers are completely sterile and totally free of biological life. This is of course only theoretical, as accomplishing this practically is extremely difficult.

Regardless of which method you go with, compared to factory produced and sealed bottled water you will have to regularly inspect and likely treat your water to keep it free of any would-be contamination like algae or bacteria.

Treatment methods vary depending on the quantity, your storage solution, and what sort of contaminant you are trying to combat. See the next section for more info.

Long Term Storage Water May Still Need Treatment

It might be the last thing you want to do under the circumstances, but keep in mind that water you have had in storage for a period of time might still need treatment before it is safe to drink.

Microscopic life that is present in the water could well be continuing to multiply and over time your water, which appears crystal clear, might really be a tiny ecosystem full of all sorts of harmful things!

Bleach. Common sodium hypochlorite household bleach, with no fragrances and no thickeners; highly effective at eliminating bacteria and other pathogens in clear water.

Chemical disinfectant. Purpose designed off the shelf treatment chemicals for the same purpose. Read up on the manufacturer’s instructions and follow them exactly for best results. Many such chemicals can significantly alter the taste of water.

Filtration. Consider filtering your water that is coming out of storage. The best filters can also purify, or at least improve, the quality of water that is infected with various pathogens.

Sunlight. It is possible to destroy harmful germs by placing your water in clear containers and then putting those containers in direct, high value sunlight for anywhere from 6 to 12 hours. You can’t leave your water in sunlight forever, unfortunately; it will promote the growth of algae.

Boiling. Boil water (at a roiling boil) for at least a minute and you can be confident that any lurking germs are history. Let it cool then use as normal.


Water does not really have a shelf life though you will lose water to evaporation over time no matter how tightly sealed your container is. Any source of factory sealed water that is then opened will become vulnerable to contamination, especially if you drink from it.

Larger, home filled containers will usually require. Periodic treatment over time to prevent the infestation of algae, bacteria and other undesirable microscopic life.

4 thoughts on “How Long Can You Store Water?”

  1. I kept commercial bottled water in a garage in Phoenix AZ for a few years. There was no light exposure, but extreme heat exposure. After a year, the translucent polypropylene gallons tasted like plastic, nasty but drinkable. After 2 years, the water tasted horrible and gave me a burning sensation in my throat. It had also lost at least a pint of water, even though it hadn’t been opened. I also had a flat of pint hdpe water bottles there. After a year, those were still okay. They started to taste like plastic after 2 years. They also lost water, about 20%. I try to keep my water inside the house now, and don’t buy those PP gallons any more.

  2. This is to verify what you said about water itself not going bad. I recently opened a gallon of water that I had stored away in 2009, 12 years ago. The water was clear, no smell and tasted good. My wife and a neighbor also drank some the next day, all good.

    What I had done: used a clean gallon plastic bottle that juice had come in (PETE type plastic). Filled with a little tap water from a municipal source, added 8 drops of a chlorine bleach (sodium hypochlorite 8.75%) and then filled the bottle up. It has been continuously stored in a dark room at between 58 and 68 degrees F

  3. I have several 5-7 gallon water containers and I empty, clean, and refill them when day light savings occurs twice a year.

  4. After my wife passed away 4 yrs ago,I started purchasing packs of bottled water which I put or stored in the basement, some sitting on the concrete floor, some on a wood pallet. I’m slowly using it up, have replaced some of the early packs. So far, the taste has been okay

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