There is a piece of prepper lore that tells us water from a natural source that is fast-moving, bubbling, or rapid is safe to drink from. Conversely it informs us that we should never drink from slow moving, nearly still or standing water. If you consider this advice it would seem that sourcing water from a waterfall would check all of those desirable boxes, being both frothy and rapidly moving. It certainly looks refreshing.
But is water from a waterfall safe to drink? Water from a waterfall is not inherently safer or less safe than water taken from any other natural source, and the quality of the water taken from a waterfall is completely dependent upon contaminants that have entered it from upstream.
Dirty water that goes over a waterfall is still dirty water and can still make you very sick or worse you if you drink it without treatment.
Sadly, waterfalls do not work as any sort of natural purification method, and water heading for a waterfall does not necessarily originate from any pure or inherently safe source.
There is more to consider on this matter; we will discuss it below.
Whitewater Does Not Equal Safe Water
Although I’m not entirely sure where it originated from, the old timers’ wisdom that informs us whitewater, rapids and other rushing forms of fast-moving water are somehow safer to drink has persisted over the many decades right up to today, and the surest sign of a greenhorn prepper or outdoorsman is them believing in this falsehood.
Regardless of how it got started or why, you can at least understand the reason behind it: water that is bubbling and frothy appears clearer and cleaner than it would when it is moving slowly or standing still. It certainly looks more refreshing if you ask me!
Unfortunately, there is no mechanical or chemical process at play that purifies the water moving through rapids or down a babbling brook, or over the long drop of a waterfall. Whatever contaminants are in the water remain even as it sloshes and froths.
Whether you take it from a still source or a fast-moving one, you are still going to have to treat and purify your water, unless you want to roll the dice on contracting some kind of nasty ailment.
Contamination Carries
The crux of the problem when comes to water contamination, including the contamination of water heading over a waterfall, is that anything in the water upstream from where you source it could potentially be carried downstream and right into your container, or directly into your mouth if you are drinking straight from the source.
For instance, you might be drawing water from what appears to be a crystal clear and utterly pristine part of the stream in the deep, remote reaches of Alaska.
“It is probably fed by glacial runoff”, you think to yourself, “and has been locked in stasis completely untouched by the ravages of mankind’s pollution for all these many centuries until this very day!”
“This is probably the purest water you are ever going to taste”, you think out loud, as it trickles into your canteen, burbling and utterly cold.
Unfortunately for you if you had walked just another 125 yards upstream from where you are standing at that very moment, you would find the gargantuan corpse of a Yukon moose that is already badly decomposing, no doubt infusing the entirety of the water with all manner of bacteria and by-products of necrosis.
Unwittingly you take a long swallow of cold, clear but totally moose-y water…
This is super gross, because of course it is, but more importantly, you are probably now on the fast track to catching some hideous disease, or at the very least getting very sick to your stomach, neither of which is a good thing in the backcountry, and either of which could spell certain death if you are already in the middle of a survivor situation.
Waterfalls Are Not Pristine Sources
Keep in mind that the water being sourced at the waterfall is not necessarily any purer than the water mentioned in the previous (and hopefully only hypothetical) example.
It isn’t burbling up to ground level directly from the spring. It is not pure glacial runoff taken immediately from the source.
Most water has to go a very long way before it reaches a waterfall, and that means it will be exposed to all kinds of potential contaminants, natural and man-made.
As time goes on, the once remote and nominally pure natural sources of water have suffered from increasing contact and contamination from man-made forces.
Industrial accidents, oil drilling, fracking, litter, rerouting of rivers, disturbing of animal migratory paths, and innumerable other factors all lead to an increase in contamination for most of our natural water sources. This results in first, second and third order effects.
But even without the interference of mankind, or just a minimally invasive presence from man, water found out in the world is simply often filthy.
Animals drink from it. They walk in it. They bathe in it, and poop and pee in it. And as mentioned they even die in it. Fish have sex in it, lay their eggs in it, and die in droves in it.
Put a sample of water taken from any natural source on a petri dish, fire up your microscope and strap in because you are about to see a universe of microscopic life through the eyepiece, and tons of other debris besides.
Consider that the river or stream feeding your waterfall might make a journey of many a-mile before it reaches the falls themselves.
In that time I could pass countless farms and all their runoff, industrial sites, many thousands of animals making use of the water in one way or another, hundreds of animals that have died in it and untold amounts of litter.
This hideously filthy water is even now making its way to your canteen.
The roaring, splashing water going over the edge of a waterfall is not somehow made miraculously clean by doing so. Thinking that it is a major mistake.
Waterfall-Sourced Water Must Be Treated
This is a long-winded way of saying that you must treat water sourced from a waterfall the same as you would water taken from any other natural source.
If you have a water filter, definitely employ it. If you use sterilization tablets, do so now. Filter it and then boil it, triple treat it.
Whatever you do, do it. Just make sure you are treating it if you want to minimize the chances that you will contract something nasty from it.
Conclusion
Water sourced from a waterfall is not inherently safe to drink, as if the water was contaminated prior to reaching the falls it remains contaminated once it has gone over the falls.
Any water you plan on drinking that is taken directly from or below a waterfall must be treated in accordance with standard practices for water taken from any natural source.