Question:
I haven't introduced myself yet. You can call me Lucy. I live in Utah with my NON-survivalist husband.

I have a few quick questions about water. I understand the general water guidelines but I would like to know what the bare minimum requirement is in a worst-case scenario situation.

What is the MINIMUM amount of water needed to survive? I believe the Coast Guard advises that two 4-ounce portions are needed in a 24 hour period. Is that correct?

How long can a person survive on this minimal amount of water? I assume if you're going to get by on a such a small amount, you can't expend any extra energy.

Does anyone have links or resources on this topic? So far I've come up dry.

Answer: There is not really any such thing as average. The rule of thumb is to allow a minimum of 1 gallon per day, per person. This allows for cooking and minimal washing. There is a great deal of difference in the amount of water needed at 85 to 90 degrees F and at 55 to 70. If it is cool, and you are not moving or exercising, and your diet contains water (canned peaches, for example), then you will need less water to drink. If it is 85, you are hiking, and you are eating beef jerky, then you will need relatively more water. There are other factors, but temperature, activity and diet all have a big effect on water usage. How long someone can survive with little or no water is also dependant on that person's individual physiology.

What circumstances do you envision for your hypothetical person? Sitting in a fallout shelter? Hiking in the woods? Car broke down in the Mojave?