Finding and trusting water sources
We've spent five lessons on how much water to carry. Today we're talking about the water you don't carry, the water that's already out there on the trail, and how to think about it without getting yourself in trouble.
I'll say this up front. My class is day hikes on marked trails, and my honest opinion is you should plan to carry all the water you need and treat anything on the trail as backup, not as part of the plan. That's not me being extra cautious for the sake of it. It's because trusting a water source means you have to know some things I don't teach in this class, and I'd rather be straight with you about that than pretend otherwise.
Why this matters even if you're not "using" trail water
Streams and springs on Wasatch trails look clean. Cold, clear, moving fast over rock. It doesn't matter. Giardia and other stuff you don't want live in water that looks perfect. You can't eyeball it and know.
So here's the honest version of what I do: I carry what I calculated from the last lesson, plus my buffer, and I treat any stream I pass as a "nice to look at" rather than a "nice to drink." If I'm ever in a spot where I'd actually need to filter or treat water to get down safely, that's a sign I planned the hike wrong, not a sign I need better filter gear.
If you do want to treat water (a beginner's honest starting point)
Some of you are working toward longer routes where carrying every drop gets heavy, and I get that. If you want to learn to treat water, here's the beginner-level version, plainly stated:
- A pump or squeeze filter removes bacteria and protozoa (the giardia-type stuff). Cheap, small, easy to find at any outdoor store along the Wasatch Front.
- It does not remove viruses, which matters more in some countries than here, and it does not remove chemical contamination. Filters have limits. Know what yours does.
- Purification tablets work as a backup or a second method, but they take time, usually 30 minutes to a few hours, and they leave a taste.
- Boiling works too, if you've got a stove with you, which most day hikers don't.
That's the beginner overview. I'm not a wilderness water expert and I won't pretend to be one. If you're planning multi-day backcountry trips, that's a different class than mine and you'll want someone who actually teaches that.
Trusting the source itself
Even with a filter, you'll want to think about the source, not just the water.
- Moving water beats standing water. A stream beats a stagnant pool every time.
- Upstream matters. Water below a popular camping area or near livestock trails is riskier than water higher up, closer to the source.
- Late-season flow is unreliable. A stream that's a solid flow in June can be a trickle or dry by September. Don't plan around a water source you haven't confirmed is currently running. Trail reports and recent hiker photos help here.
Why the paper map matters for this too
I've told you before that a paper map goes in my pack before anything else. Here's part of why. Trail apps and online descriptions will often mark water sources, springs, streams, seasonal crossings. That's useful information. But I've had it happen where I was relying on my phone for exactly this kind of detail and lost signal partway up the canyon. No bars, no map, no way to confirm anything I'd planned around.
I got down fine that day. But I was quiet about it for a good day afterward, because it was a dumb thing to let happen. Now the paper map comes first, every time, and if it's got water sources marked on it, I check that before I leave the house, not on the trail when I'm already thirsty and hoping.
The practical version, for home
Before any hike where water sources come up in trail descriptions:
- Look up recent trip reports for the specific week or month you're going. Water availability changes fast with the season.
- Mark any sources on your paper map, not just your phone.
- Decide before you leave whether you're treating water on this trip or just carrying everything. Don't decide that decision on the trail.
- If you're not confident in your filtering method, don't count on it. Carry more instead.
Before next time
Pull up a trail you're thinking about doing this summer and see if any water sources are marked on the map or mentioned in recent trip reports. Bring what you find to next class, we'll talk about whether it's the kind of source worth planning around or just a nice thing to look at on your way up.