How much water do you need to flush the toilet, cook and wash?
The short answer
Ready.gov's 1 gallon per person per day is for drinking and basic sanitation. Flushing the toilet is extra: about 1.2 gallons each time, poured straight into the bowl. That water doesn't have to be drinkable, so fill the bathtub or use pool water for it, and save your clean water for drinking, cooking, brushing teeth and washing hands.
Which water to use for what
| Use | Water to use | Why |
|---|---|---|
| Drinking | Clean stored water or bottled water | The CDC says not to drink water that may be unsafe |
| Cooking and washing food | Clean water | The CDC lists food prep among the uses that need safe water |
| Brushing teeth | Clean water | Same CDC rule |
| Washing hands | Clean water and soap, or hand sanitizer with at least 60% alcohol | The CDC suggests sanitizer when safe water is short |
| Washing dishes | Clean water | Same CDC rule |
| Flushing the toilet | Bathtub, pool, spa or other non-drinking water | It goes straight down the drain |
How to flush a toilet without running water
The Alameda County Water District's steps for a water shutoff:
- Keep a bucket or other container by the toilet.
- Fill it with about 1.2 gallons of water.
- Pour it quickly, straight into the bowl, from 1 to 2 feet up.
Pouring into the bowl works because a quick rush of water starts the flush on its own. That's about what a modern toilet uses anyway: 1.28 to 1.6 gallons per flush, according to the EPA. Older toilets use as much as 6.
Work out your flushing water
Flushing water calculator
22gallons
About 7.2 gallons a day, on top of your drinking water. It doesn't need to be drinking water.
If water is short, flushing less often cuts this number a lot.
Where to get non-drinking water
- The bathtub. If you know a water shutoff or storm is coming, fill the tub for flushing. The City of Panama City Beach suggests exactly that.
- A pool or spa. The CDC says pool and spa water is fine for washing and cleaning, but not for drinking.
- Buckets for washing. Fill a couple before an outage, for cleaning and general washing.
Save clean water for cooking
Before a planned outage or a storm, fill pots on the stove and pitchers in the fridge, so you're not opening your stored containers for every meal. Cook food that needs little water, and keep the water from canned vegetables: the CDC counts it as drinking water. When you're down to stored water, our guide to making water safe to drink shows what to do if your stored water runs out.
Get your drinking water number
The water storage calculator works out the drinking and sanitation water for your household, with pets and hot weather. Add your flushing water on top.