Storing Two Weeks of Water in a Small Apartment

Water is the first thing to go wrong in a flat when the mains supply is interrupted, and the last thing most tenants think to prepare for. There's no garden, no rain butt, no well — just taps that depend entirely on pumps somewhere else in the building or the street. Storing water properly in a small space is less about volume and more about container choice, rotation and knowing where your building's weak points are.

A house on a private supply or with a header tank often has some buffer when the mains cut out. Most flats don't. Water is pushed up by a pump, and if that pump loses power or the building's stopcock gets shut for a repair, taps above the first floor or two can run dry within minutes rather than hours. There's rarely a loft tank to fall back on, and communal plumbing means a fault two floors down affects you too.

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   Choose containers that fit your space. Stackable 10-20 litre food-grade jugs under a bed or in a cupboard beat one huge drum you can't lift or manoeuvre through a doorway.

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   Fill from the tap, not from a bottle you already trust. Tap water that meets local drinking water standards doesn't need treating before storage; just make sure the container itself is food-safe and was rinsed with a little diluted unscented bleach before first use.

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   Date every container. Write the fill date on with a marker. Rotate stored tap water roughly every six months even though it stays safe far longer, simply so it never sits forgotten.

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   Keep it cool, dark and off the floor slightly. Heat and direct light encourage algae and off-tastes even in sealed containers; a cupboard or wardrobe base works better than a balcony.

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   Split storage between drinking and flushing/washing. Keep a clearly separate stock — even old, less pristine containers — for topping up the toilet cistern or washing, so your best water isn't used on non-drinking jobs.

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   Fill the bath at the first sign of trouble. If you get any warning of a planned interruption, or notice pressure dropping, fill the bath and every spare container immediately — treat it as backup, not drinking stock, since baths aren't food-safe vessels.

A commonly used planning figure is about 3-4 litres of drinking water per person per day, plus more for cooking and basic hygiene. For a household of two, aiming to hold roughly 20-30 litres of dedicated drinking water covers a few days without turning a hallway into a warehouse. This is a guide, not a rule — bigger households or anyone with medical needs should scale up.

If an outage runs past a few days, or if you suspect contamination rather than simple pump failure — discoloured water, a boil notice, flooding nearby — stored tap water won't help with a contamination problem because it was already drawn before the issue was known. At that point you need reliable purification rather than more storage, and a written 72-hour emergency plan that covers what happens if the outage runs longer.

• Relying solely on bottled water bought once and never rotated, then finding half of it has been quietly used for other things
• Storing containers somewhere warm, like near a boiler or on a sunny windowsill
• Using old milk or juice containers, which are hard to fully clean and can taint the water
• Assuming a full bath is drinking water — it isn't, treat it as washing and flushing stock only

Does stored tap water need purification tablets or filtering before drinking? Not if it came from a mains supply that was safe when you filled the container and the container itself was clean. Treatment matters when you're drawing from an unknown source later, not for water you already trusted.

Will plastic containers leach anything over time? Food-grade containers designed for water storage are fine for the kind of timescales involved here (months, with rotation). Avoid containers that previously held chemicals or that aren't rated food-safe.

• US CDC, making water safe in an emergency (https://www.cdc.gov/healthywater/emergency/making-water-safe.html)
• World Health Organization, drinking water (https://www.who.int/health-topics/drinking-water)
• Ready.gov, water storage guidance (https://www.ready.gov/)