Drinking Water, Part 1

It’s something we do.  It’s something we need. It’s the first thing we must secure in survival situations. In preparation for these situations, it’s the first resource we must find a way to store, filter, carry, locate, and safely consume. I want to organize my thoughts about water before I do anything else here.

What Are My Water Requirements?

The most commonly held belief about adult water consumption is that at least 8 cups, or about 2 liters of water are necessary to stay hydrated. There’s plenty of conjecture around the topic, but there is limited fact-based information off which we can make a really accurate estimate. Many factors play into an individual’s water needs, including body size and weight, biological sex, age, organ function, ambient temperature, activity levels, and future water availability.

One relatively reasonable metric that has been used to estimate minimum water requirements is to determine the output in order to inform the input. How much urine does a person produce, on average?  The idea being to replace what is excreted, one would then attempt to consume slightly more than that amount in order to account for metabolic processes.

An average adult human body loses an estimated 1.2L of water per day through the processes of waste excretion, perspiration, and respiration. Of course, this varies on the individual level.  Men tend to run through more water than women.  Larger people use more than smaller people. Activity level, relative humidity, and environmental temperature will all contribute to differences in an individual’s water needs. Mayo Clinic estimates that men should consume about 3 liters per day, and women about 2.2. 

Anyway, all this means that you need to plan to have enough water, per person, per day, to account not only for your drinking requirements, but also for cooking and washing. A reasonable, round estimate that I’m using for my own preps is 3 gallons (~11.4 liters) per person, per day.  My family includes me, my husband, and our two growing boys. That means that, at the time of this writing, I have about enough stored water for a week for all four of us, without doing much rationing. That’s it.  And that looks like a lot when you’re storing it in a very small home. This is an example of why we must not only store water to be readily available, but we must also locate nearby water sources, and find ways of purifying that water for drinking.

In later posts, I’ll discuss each of those topics in depth.