Tuesday, May 2, 2023

Rubbish Advice: 1 Gallon of Water Per Person Per Day

By Tim Gamble

Please Subscribe by Email, and find me on Gab (@TimGamble) and Twitter (@TimGambleSpeaks

Bottom Line Up Front (BLUF): In an off-grid or long-term grid-down situation, you need much more than the often repeated advice of 1 gallon of water per person per day. 

We have all heard this formula before: 1 gallon of water per person per day. This is common advice found throughout the prepper and homesteading communities. It is also pure rubbish.

What some folks don't realize is that this water "rule" comes from wilderness survival, where the goal is to simply not die from dehydration until you get rescued, hopefully within just a few days. It is not meant for longer-term survival, which comes with many other considerations beyond just avoiding death by dehydration. 

So, how much water do we need?

For long-term survival in an off-grid or grid-down situation, my recommendation would be a minimum of 2 gallons of potable water (clean of germs and dangerous chemicals) per person per day for drinking, food prep, cooking, cleaning cookware, dishes, and utensils, brushing teeth, cleaning wounds, and so forth. By the way, when washing hands before meals use potable water only, to avoid contaminating the food. Again, this is a minimum recommendation for potable water. More is always better.

Also keep in mind, in a grid-down situation, most of us will be doing more physical work than usual, and won't have the luxury of air conditioning. This means we will likely need to drink even more water than usual, just to stay even with our sweating. 

In addition to this potable water for human internal consumption, we also need water for external use, such as flushing toilets, general household cleaning and sanitation, and bathing (external use only). 

Don't forget our animals! If we have pets and/or livestock, they need water, too. What are the water plans for them?

Have a garden? More water. Most places don't get enough consistent rainfall to depend solely rain to water our gardens. Rain barrel or trash can collection may work nicely for this, if we are getting enough rain. But, what if there is a drought?

Lots of considerations, and your exact needs will vary depending on your particular situation. But it is obvious we are all going to need more than 1 gallon per person per day. 

See Also: Emergency Water Storage (my article from January 2019)


AD: Kaito KA500 Emergency Radio. This one has is all: AM/FM/SW/NOAA (weather alert) bands; powered five ways (electrical cord, USB port, AA batteries, solar, and hand-crank); plus flashlight, reading lamp, and cellphone charger.


  1. Outstanding! Well done, Tim.

  2. Excellent. I wonder if anyone else has thought of checking their monthly usage from their water bill and dividing by 30? Seems to me, that'd be a good starting point. YMMV.

  3. That is a great idea! Thanks for mentioning it.


Comments are posted without moderation. Use caution when following links, and beware of SPAM and fake links. Please keep discussions civil and on-topic. NOTE: Certain ad-blockers and other security software installed on your browser may block the ability to leave comments on this website. This issue is with that software, not this website.