You fill the tub during a storm so you have a backup supply of water if your taps stop working or become unsafe, mainly for flushing toilets, basic washing, and cleaning, not for drinking.

Quick Scoop: Why this is a thing

When a big storm rolls in, a lot can go wrong at once: power can go out, pipes can freeze or burst, or your local water system can get disrupted or contaminated. If that happens, you might suddenly have no running water at all—or water that isn’t safe to use.

Filling the bathtub beforehand is a low-tech, old‑school prep move that gives you a big “water battery” sitting right in your home. You’re not doing it to be fancy; you’re doing it so you can still handle life’s unglamorous basics when everything else goes sideways.

What that tub of water is actually for

Most experts stress that tub water is for non‑drinking uses unless you purify it.

You can use it to:

  • Flush toilets (by pouring a bucket of water directly into the bowl to force a flush).
  • Wash hands and do quick sponge baths so you can stay reasonably clean.
  • Rinse dishes or wipe down surfaces if you’re stuck without running water.

Some guides say you can use it for drinking in a true emergency if you’ve lined the tub with a special bag or use proper purification (boiling, filters, or purification tablets). But they still prefer you store separate clean drinking water in bottles, pitchers, or jugs before the storm hits.

Why storms mess with your water

Different storms can break your water supply in different ways:

  • Winter storms: When temps drop below around 20°F, pipes can freeze and cut off your water completely.
  • Power outages: If pumps or treatment plants lose power, water pressure can drop or stop, even if the pipes themselves are fine.
  • Heavy rain / hurricanes: Flooding can contaminate wells or municipal systems, making tap water unsafe until it’s tested and cleared.

In all those scenarios, the water you stored earlier in the tub is still sitting there, ready for basic tasks even if nothing comes out of your faucets.

How much good does one tub do?

A standard bathtub can hold roughly 40–60 gallons of water. That’s usually enough for:

  • A couple of days of toilet flushing, hand washing, and sponge baths for two adults.
  • Around a day of those same basics for a family of four.

It’s not luxury living, but it can bridge the gap until the power or water supply comes back.

Safety notes people often forget

There are a few important cautions:

  • Don’t assume tub water is safe to drink. Bathtubs aren’t sterile, and tiny residues of soap, cleaners, or germs can linger.
  • If you must drink it, purify it properly (boil at least one minute, use a proper filter, or purification tablets) and only as a last resort.
  • If you have small kids, treat a full tub like a serious drowning hazard—keep the bathroom door shut and supervise.

In one line: People fill the tub during a storm because it’s an easy way to stockpile usable water for toilets, washing, and cleaning in case the power or pipes fail, while keeping separate, cleaner water for drinking if possible.

Information gathered from public forums or data available on the internet and portrayed here.