Water… Need Water

Let’s complete a brief water consumption exercise, shall we? Stop a moment and think about what you use water for on an average day, how often, and how much? Chances are if you’re reading this, you don’t have to think about this hardly ever. You can walk over to the tap in your kitchen or bathroom, grab a filtered pitcher out of your refrigerator or it comes filtered straight from a dispenser built-in to your refrigerator, and have an unlimited supply of clean, potable water.

Wake up, use the bathroom, flush the toilet, wash your hands. Wash your face, brush your teeth. Make a hot cup of coffee or tea, prepare breakfast, drink water, fill up your water bottle. Without even a shower in the morning, how many liters of water do you think you would have already utilized? How much water was used to clean your fresh clothes you put on? This is just within the first hour of waking up.

What if you had to filter or treat all of your water consumed or risk being sickened? What if you had to carry all of the water you will need for half a day or even an entire day? Or even longer? If you are a thru-hiker, then this will be one of the most important things you calculate each and every day. 

I’ll need water for:

  1. Drinking
  2. Cooking
  3. Hygiene


We are all supposed to drink 8 glasses of water per day. According to the Mayo Clinic, the average, healthy adult living in a temperate climate should drink 3.7L and 2.7L each day for males and females, respectively. If you are only drinking eight eight-ounce glasses per day, that’s less than 2 L. This is not accounting for other drinks like coffee, tea, etc., and fruits and vegetables that also provide additional water. Still, eight glasses per day is probably not enough. 

Factors of exercise, like hiking 20+ miles per day, for example, environment, such as 100° F temperatures in the desert, and overall health, I’m pushing 40 years old, all play factors into how much water I’ll be consuming.

How much water will I need while actually hiking? REI says a hiker needs between 0.5-1 L per hour. This article on GreenBelly states 1 L every hour if hiking in hot, humid weather or at high elevations. Another great resource, SectionHiker, recommends 1 L every 2 hours for a day hike. Obviously, this is less strenuous if you are carrying a light daypack. Finally, some anecdotal amounts I gathered on the r/PacificCrestTrail subreddit suggested 1 L every 3.5 miles in high heat, 1 L every 5 miles in moderate temperatures, and 1 L every 10 miles in cold temperatures. 

A common bit of advice is to also “camel up” at the start, or at a water source. This means drinking water that you then will not have to carry, extending your hiking range. If I drink 1 L at a water source, then I just bought myself a few miles of distance on the trail before I need to start depleting the water I am carrying.


If I am dry camping, with no water source, then I’ll need about 1 L for cooking, drinking and cleanup. The best method to extend my water use is making “hiker tea” by heating up water in your cook mug/pot after you finish eating, scraping all the leftover food bits off the mug as best you can, then drink it down. You just cleaned your mug and hydrated yourself with the same water. It might sound unappetizing but if you don’t have a water source nearby then this is an option. 

Most importantly it’s a good Leave No Trace practice to drink down your “hiker tea” after your meal. Using biodegradable soap, and scattering your dishwater, AFTER straining out any food bits, still alters the environment you are in. Your dirty dishwater affects the plants, the experience of other hikers that are using that campsite after you, and attracts animals. Anything you are doing needs to be done at least 200 feet away from any water, trail, or camp. Refer to LNT Principle 3: Dispose of Waste Properly.

If you simply cannot stomach your own leftover food, then you can use a freezer-grade ziplock bag to rehydrate your meal. These bags can withstand hot water for your meal. After you are done eating you can pack out your used ziplock bag with your other trash. Then there is no mug to clean and dirty water to discard. This is assuming you have repackaged your meal into a ziplock bag, rather than the bulky original packaging, or that you even need hot water for your meal. Maybe you’re a cold soaker (no stove) or eating everything wrapped in a tortilla.


I’ll need some water for personal hygiene. Wet Wipes are a great LNT option because I can clean myself up and pack them out in my trash. I’ve read of hikers drying out the wipes so they are lighter, then rehydrating them as needed before use. When using water to brush my teeth, the post-brushing toothpaste foam should be “spit-sprayed” 200 feet away from water, trail, and camp. I’ll estimate this water into the 1 L for my cooking needs if dry camping. Your mileage may vary (YMMV).

Where will I get water?

I plan on using two resources to verify and locate water sources along the PCT. One is the PCT Water Report which is a crowdsourced report of water sources and current status. The second is my Guthook Guides navigation app. The app allows hikers to update waypoints with notes, such as water source locations. Both rely on the information from other hikers. A permanent body of water or a fixed source, like a water tap at a campground, is more reliable, a seasonal stream dependent on precipitation, less reliable, and water caches of water bottles placed by trail angels are the least reliable. The safe bet is for me to assume that water caches will be empty when I reach them and to carry adequate water to reach the next reliable water source. 

There are also other water sources, like stagnant puddles, water troughs, water tanks, wells, and others that will be new to me, and under normal circumstances some of these I would never think to drink from. I’ll have never been so elated to use a water spigot on the side of a building. The excitement is also finding water fresh from glaciers and snowmelt high in the mountains that has not been touched by anyone or anything.

The most difficult section for water sources is not surprisingly the desert section. This also happens to be the longest section, at 700 miles. Even though I will crest 10,000’ in elevation in the “desert” if I opt to take the side trip to Mount San Jacinto Peak at 10,834’, water sources are challenging until I reach the Sierra Nevada. I estimate I will be carrying 2-6L dependent on my next water source. For reference, one gallon is only 3.78 liters. Six liters is 1.59 gallons. Finally, 1 liter weighs 2.2 pounds.

One of the most notoriously difficult stretches in the desert is the LA aqueduct part of the PCT. Despite literally walking on top of the LA aqueduct, carrying 712 cubic feet of water per second to Los Angeles, there is no reliable water source for 33+ miles according to my math on the Guthook app right now. There is a possible water cache that shaves the waterless stretch down to 26.8 miles. It’s common for hikers to hike this at night, or anytime the sun is not directly overhead to avoid the exposure to the sun and heat of the Mojave Desert.

When I do find water, then what?

Water Carry: I am going to have a carrying capacity of 6L for the desert section. I will carry two 1L Smart Water bottles, two 1L Sawyer squeeze bags, and one 2L CNOC Vecto squeeze bag. All of these vessels will allow me to thread my Sawyer Squeeze water filter directly onto them. The squeeze bags will roll down very compact when I don’t need them and are relatively light and durable.

In the Sierra, I’ll be able to drop down to 2L of water capacity, as we did on the JMT. I’ll have the luxury of abundant water sources and will rarely have to even plan where I’ll get water from next.

If I recall correctly, I may need to add some capacity for NorCal and Oregon as it will be very hot and with some dry sections. By then I’ll have become accustomed to checking for water sources on the Guthook Guides app and more finely attuned at estimating my hiking range per liter of water.

Water Treatment

I am starting my hike with the Sawyer Squeeze water filter. This is the largest of three portable filters that Sawyer makes; the smaller two being the Sawyer Mini and Sawyer Micro

I used the Sawyer Mini on my JMT hike and after a couple of weeks on trail filtering water for two people the flow rate deteriorated greatly. My hope is that for just a one-ounce weight penalty the Sawyer Squeeze will maintain a better flow rate, saving time when I am filtering water. 

This time I am also taking a cleaning coupling that allows me to screw the filter on backward to my water bottle. I can backflush the clean water through the filter, cleaning out debris. This should maintain the life and efficiency of the filter. 

Other Options

A popular ultralight water treatment option is to use Aquamira. It’s a two-part solution that treats and kills bacteria and viruses. Two drawbacks I see are that it takes 5 minutes to prepare the solution before adding it to the water. Then it takes 15-30 minutes for the solution to work and the water is ready for consumption. Also, it does nothing to remove any particulates, chunks, or floaties if you’re dipping into a particularly impure water source. 

The EPA lists a chart for the amount of bleach to add dependent on the bleach concentration. This is another ultralight option since the recommendation is only 2 drops of bleach per liter of water. There is also a 30 minute treatment time, similar to Aquamira. 

You can also go full survivor mode and not filter your water. But that’s just asking for stomach trouble in my opinion. Pack some extra Imodium if you opt not to filter your water. 

How much water to start?

On Thursday, my cousin will drop me off at the southern terminus of the PCT. Mile marker 0. I’ll have 4 days worth of food, enough to last me until I pick up my first resupply box at Laguna Mountain Lodge and Store. 

But how much water do I need to start with? The general consensus is I need enough water to last me to Lake Morena at mile marker 20. As of Tuesday evening, there is one water source at mile marker 4.4 reported on the Guthook app. 


I’m planning to pace my start and reach Lake Morena on day 2. I’ll start at Campo with 6L of water, estimating 3L per day. At least enough water to reach Lake Morena before dinner. Lake Morena will be an early treat since it is a campground that has water, bathrooms, showers, and a small store down the road. I’ll be living the good life. 

Water Resource Review

  • Do I have water? 
  • If yes, is it enough to reach my next water source?
  • If no, find a divining rod quick!

Next update from the trail. I’ll catch you on the flip side.

Thank you for reading. 

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Comments 3

  • JustBob : Apr 28th

    Great article. (Some I never think about)

    • Daniel Gerken : May 6th

      Hi JustBob,
      Thanks for reading and comment. Hopefully you found something helpful in my own learning process.


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