A jerry can for water storage at home is a sealed 20-litre steel or plastic container built to hold a household's emergency drinking reserve, refillable for years rather than bought once and binned like crates of bottled water. Households need something that sits quietly in a cupboard or garage for months at a time, not gear built for daily carry on the trail, so the priorities here are food-safe material, a tight seal, and honest labelling of what's inside.
- A genuine 20-litre jerry can for water storage holds roughly 20kg of water once full, enough for one adult's drinking needs for close to a week.
- Never fill a used fuel jerry can with drinking water in 2026 or any year — residual diesel or petrol taint doesn't wash out.
- New-manufacture plastic jerry cans, not ex-military steel fuel cans, are the safer default for home drinking water storage.
- Rotate stored tap water every 6 months and keep cans out of direct sunlight to stop algae growth and plastic degradation.
- Pair a jerry can with a portable filter or purification tablets as backup, not a replacement, for water of unknown origin.
Why jerry cans matter for emergency water storage at home
Mains water supply gets interrupted by burst pipes, freezing weather, or planned works, and when it happens most households discover they have no reserve at all. A jerry can is the simplest fix: no pump, no power, no plumbing knowledge needed, just a sealed container you can carry to a tap and fill.
The same NATO-pattern 20-litre can that's stocked for off-grid fuel storage is the design lineage behind most water jerry cans on the market in 2026 — same stackable shape, same screw cap, different internal lining. That crossover matters because it's also the most common mistake: a can built and used for diesel is not a water can, whatever the shape suggests.
The widely used rule of thumb in emergency-planning guidance is around 3-4 litres of drinking water per person per day, more if you're using it for cooking or basic hygiene too. A single 20-litre can covers one adult for roughly a week on drinking water alone — which is why most households need several cans, not one big tank.
Calculate how much water you actually need
Work out your household's minimum before buying anything.
- Multiply people in the household by 3-4 litres per day
- Decide how many days of cover you actually want — 3 days covers most short outages, 14 covers a genuinely bad week
- Add extra for pets, since they need drinking water too
- Round up to the nearest full jerry can rather than leaving a part-filled one
- Split the total across at least two containers so one failure doesn't wipe out the whole reserve
Choose the right can for drinking water, not fuel
Steel and plastic jerry cans both hold 20 litres in the NATO pattern, but they're not interchangeable for this job.
- Pick food-grade plastic (HDPE) for anything going straight into drinking storage
- Avoid ex-military steel fuel cans unless they're sold and graded specifically as water cans
- Check for a wide-mouth filler cap — narrow military filler necks are slow and awkward to clean
- Look for UV-stabilised plastic if the can will sit anywhere near a window or shed skylight
- Confirm the seal is intact before buying secondhand or graded surplus stock
Clean and prepare a used or new can before filling
Even a brand-new plastic can needs a rinse before it touches drinking water.
- Rinse with a small amount of unscented household bleach diluted in water, then rinse thoroughly with clean water
- Never use a can that previously held fuel, oil, or chemicals — the taint is permanent
- Dry the cap threads fully to stop mould forming under the seal
- Do a smell test before first fill; if it smells of plastic or chemicals, rinse again
- Label the can clearly as "drinking water" with the fill date
Fill and treat the water correctly
Tap water in the UK is safe to store as-is, but treatment adds a margin of safety for longer storage.
- Fill straight from the mains tap, right to the top to reduce air space
- Add water purification tablets if storing for more than a few months, or if the source is anything other than treated mains
- Screw the cap down fully and check for leaks by tipping the can on its side briefly
- Store away from any chemicals, fuel, or paint that could off-gas through the plastic
- Keep one smaller container filled and treated as your "first grab" supply
Store the cans properly at home
Where a can sits matters as much as what's in it.
- Keep cans in a cool, dark spot — a garage shelf or understairs cupboard beats a shed with a window
- Raise cans off a concrete floor slightly to stop condensation and cold transfer
- Stack no more than two full 20-litre cans high on standard shelving; each one weighs close to 20kg full
- Keep cans away from direct sunlight to stop algae growth inside clear plastic
- Separate drinking water cans physically from any fuel or oil cans in the same space
Rotate and test your stock
Stored water isn't a "fill and forget" job.
- Rotate tap water storage roughly every 6 months, using the old stock for washing or the garden rather than tipping it away
- Write the fill date on the can in marker pen so rotation is a glance, not a guess
- Check seals and caps for cracking once a year, especially on plastic left in a cold garage
- Taste-test rotated water before drinking it — flat or plastic-tasting water is still safe but worth refreshing
- Rebuy or reseal any can that's lost its seal integrity rather than trying to patch it
Add filtration and purification as backup
A jerry can solves storage, not contamination from an unknown source.
- Keep water purification tablets in the same cupboard as your cans for water of uncertain origin
- A portable filter earns its place if you'd ever need to refill from a stream, tank, or standpipe rather than the mains
- Sediment filter bags strip visible particles before water goes anywhere near a filter or purification stage
- Never treat filtration as a substitute for a sealed, dated reserve — it's the fallback, not the plan
Once the stored reserve is sorted, filtration and purification gear rounds out the setup for water that isn't straight from the tap.
Comparing your options for home water storage
| Option | Best for | Key limitation |
|---|---|---|
| 20L steel NATO jerry can | Long-term bulk storage, gravity-fed pouring | Full can weighs close to 20kg; can taint water if not properly lined |
| 20L plastic jerry can (new) | Food-safe drinking water, lighter to carry | Less puncture-resistant than steel; UV degrades it over years outdoors |
| 25L water bladder | Flexible storage that folds flat when empty | Needs a stand or support once filled; punctures more easily than rigid plastic |
| 250L water bladder | Whole-household bulk reserve | Takes up significant floor space; near impossible to move once full |
| Bottled water crates | Zero prep, drink straight away | Most expensive per litre stored; generates ongoing plastic waste |
The plastic 20-litre jerry can is the sensible default for most homes in 2026: food-safe, light enough for one person to carry when full, and cheap to replace if the seal fails.
Common mistakes people make storing water in jerry cans at home
- Reusing a fuel can for water. Diesel and petrol residue soaks into plastic and steel linings and doesn't rinse out no matter how many times you flush it.
- Storing cans in direct sunlight. Clear or thin plastic left on a windowsill grows algae inside within weeks in warm weather.
- Never rotating stock. Water sat untouched for years past a 6-month rotation point tastes flat and risks bacterial growth if the seal has ever been broken.
- Buying one giant tank instead of several smaller cans. A single 250-litre bladder is a single point of failure — one puncture and the whole reserve is gone.
- Assuming a steel can never needs checking. Rust develops on the inside of steel cans over years of storage even when the outside looks fine.
“If the can ever held fuel, it's a fuel can for life — don't gamble drinking water on a rinse.”
FAQ
What is the best jerry can for storing drinking water at home?
A new-manufacture 20-litre food-grade plastic (HDPE) jerry can is the best choice for home drinking water storage in 2026. It's lighter than steel, won't rust, and carries no risk of fuel taint the way a repurposed military fuel can does.
How much water should I store in jerry cans for emergencies?
Plan on 3-4 litres per person per day as a minimum, which means a single 20-litre can covers one adult for close to a week. Most households store several cans split across at least two locations rather than one large tank.
Can you use a military surplus jerry can for drinking water?
Only if it's graded and sold specifically as a water can, never one that previously held fuel. Genuine ex-fuel jerry cans retain diesel or petrol residue that no amount of rinsing fully removes.
How long does water stay safe in a jerry can?
Tap water stored in a properly sealed, clean can stays safe for around 6 months before rotation is recommended. After that, taste and clarity start to drop even though the water may still be technically drinkable.
Is a steel or plastic jerry can better for water storage?
Plastic is the better default for home water storage because it's lighter, won't rust, and is easier to inspect for cracks. Steel cans hold up better to rough handling but need regular internal checks for corrosion.
How do you clean a used jerry can before filling with water?
Rinse it with diluted unscented household bleach, then flush thoroughly with clean water until no smell remains. Dry the cap threads fully afterward to stop mould building up under the seal.
Do I need to treat water before storing it long term?
Treated UK mains water is safe to store as-is for short periods, but adding purification tablets extends safe storage time. Treatment matters more if the source is anything other than mains tap water.
One last thing
The detail most people miss in 2026 buying guides: a full 20-litre jerry can weighs close to 20kg, which is more than most people expect to lift one-handed off a high shelf. Store cans at waist height or lower, not on a top shelf where the only person able to lift one down safely is whoever put it there.
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