Hydration Tips for Hikers

“A giant thirst is a great joy when quenched in time.”

– Edward Abbey, “Desert Solitaire” (1968).

Not drinking enough water may well be the most common mistake made by hikers and backpackers. Whether you are walking in the heat or the cold, at sea level or at altitude, being adequately hydrated should always be a priority.

Let’s break it down into five sections: 1. Pre-hike Research; 2. How much do I need?; 3. Hydration Techniques; 4. Dehydration, and; 5. Finding Water in a Worst-Case Scenario.

Queuing for water | Alpine Pass Route, Switzerland, 1997.

1.   Pre-Hike Research

Doing due diligence before setting out represents the foundation of your overall hydration strategy.

Study maps, guide books and check for up-to-date information on the internet. If little data can be found, call local agencies directly.

If information proves hard to come by, always err on the side of caution in regards to how much water you are carrying. Better too much than too little.

H20 preparation for the first ever traverse of Badlands National Park | South Dakota, 2016.

2.   How Much do I Need?

How much water you should drink depends on three main factors: climate, your level of exertion and your own individual needs.

  • Climate:  When hiking in hot and/or humid weather, an average of one litre per hour is generally recommended. In cooler conditions, half of that will normally suffice.

Gobi Desert – No place to be skimping on water | Mongolia, 2009.

  • Level of Exertion: The harder you are working, the more bodily fluids you are losing through respiration and perspiration. If you are not adequately replacing those fluids, you will eventually become dehydrated.
  • Individual Needs: Although general benchmarks are useful, at the end of the day we are all individuals. No two hikers needs are the same. Hiker (A) may be fine drinking 4 litres over an eight to ten hour period in hot weather, whereas Hiker (B) may need double that in order to feel properly hydrated. That being the case, how do we know as individuals how much we should drink? The answer lies in personal experience. Listen to your body and err on the side of caution when in doubt (particularly when starting out).
  • Can I drink too much? Hyponatremia (abnormally low sodium levels in the blood) may occur if a hiker drinks too much water without adequately replenishing electrolytes. When hiking in hot conditions, I add sports drink powder to my water and up my intake of salty snacks such as peanuts & pretzels.

3.   Hydration Techniques

  • Don’t Wait Until you are Thirsty:  By then it is too late. When you wake up in the morning, make a habit of drinking at least half a litre of water before breaking camp. Think of it as a “hydration” investment for the rest of the day.
  • Sun Protection: Hats provide shade. Shade keeps you cooler. Cooler temperatures mean you don’t have to drink as much water. Rocket science it ain’t. Umbrellas provide even more shade than hats, however, if you are hiking in an area prone to high winds, sometimes they can be more trouble than they’re worth.

Yours truly crossing Death Valley on the Lowest to Highest Route | CA, 2014.

Joshua “Bobcat” Stacy and Ryan “Dirtmonger” Sylva crossing Death Valley | Lowest 2 Highest Route, 2014.

  • Drink up Big at Water Sources: If you are hiking in terrain where opportunities to fill your bottles are few and far between, drink at least one litre of water before leaving each source. By doing so you will not need to carry as much to the next refill point, which in turn translates to less weight on your back and more spring in your step.
  • The Siesta Theory: In hot, largely shadeless conditions where water sources are scarce, do the bulk of your hiking whilst temperatures are cooler (i.e. early morning, late afternoon and early evening). It works like this: Begin your hiking day at sunrise. Walk until around 11am. Find yourself a shady spot and rest until 2 or 3pm. Make the most of your extended break by eating your main meal, thus enabling you to hike into the early evening without having to worry about cooking a big dinner. By following such a strategy, it is possible to make do with less water because you are resting rather than exerting during the hottest part of the day.

Stands of Joshua Trees can provide welcome shade in California’s Mojave Desert | Pacific Crest Trail, 2007.

  • Experience: Once experience has taught you how much water you need in different types of terrain and conditions, it doesn’t make sense to carry a great deal extra for security purposes. Aim at carrying enough water to enable you to arrive at the next source well hydrated, but not so much that you get there with a couple of litres still to drink. This equates to wasted energy. Obviously, an exception to this point is if you find yourself walking in an environment in which you are not certain of the quality or regularity of the water sources. In such cases, it is definitely wise to carry as much extra water as you deem necessary.
  • Not all Water Sources are Created Equal:  If possible, avoid water sources that are stagnant, foamy or have animal faeces in the vicinity. If you have no choice, use a bandana, coffee filter or stocking to pre-filter the big chunks out. If you are carrying extra fuel for your stove, now would probably be a good time to boil!

Hoping for the best | Copper Canyon Traverse, Mexico, 2013.

  • Adaptability: You may have done the research, but Mother Nature doesn’t always follow the script. Once you are out in the backcountry, if it becomes obvious that water sources you were relying upon are bone dry, you will need to reassess your hydration strategy on the fly. Take a moment to figure out which sources are most likely to still be running, then ration your water accordingly. In such cases avoid walking during the middle of the day, when your body will require significantly more fluid in order to remain hydrated.

4.   Dehydration

The importance of remaining hydrated cannot be overestimated. In warm to hot temperatures, people can survive for weeks without food, but for only three or four days without water. When water intake has been insufficient, irrespective of the climate or altitude (see below), dehydration can occur.

  • Symptoms:  Dizziness, headache, fatigue, nausea and cramps.
  • Treatment: Shade, rest, water (electrolytes, a pinch of salt or rehydrating powder are all helpful) and cooling yourself by soaking your hat/bandana/shirt.

Desert traverse between St.Paul’s and St.Anthony’s monasteries | Egypt, 1995 (Note: Some 22 years later, this remains the most dehydrated I have ever been on a hike).

  • Hiking at Altitude: The air is drier and thinner at high altitude, and due to cooler temperatures many hikers make the mistake of not drinking enough water. As the initial symptoms of AMS (Acute Mountain Sickness) are similar to those of dehydration, people often assume they have AMS when in actual fact they are simply dehydrated. Try to drink at least three to four liters of water per day when hiking at altitude, and note that both alcohol and caffeine increase dehydration. Limit your intake of both when hiking at high altitudes.

5.   Finding Water in a Worst-Case Scenario

Here are six tips on what you can do if water sources you were counting on turn out to be dry:

A.  Don’t Panic

Keeping a cool head, staying positive and making objective decisions is key in such situations.

Badlands Traverse | South Dakota, 2016.

B.  Streams

Just because a stream appears dry close to the trail, doesn’t necessarily mean that that will be the case further up towards its source. Make the effort to go and look. In addition, check downstream for any areas shaded by rocks and/or vegetation which may harbour water.

C.  Vantage Point

Climb to the nearest high point. Look for gullies, depressions and valley bottoms that show signs of vegetation (i.e. potential water sources).

D.  Livestock 

Signs of livestock generally indicate a water source in the vicinity. Grazing animals tend not to stray too far from their primary water supply. Look for converging paths leading in a downhill direction. Any water taken from sources frequented by livestock should always be treated.

Cow Patty Heaven, New Mexico | Southwestern Horseshoe, 2012.

E.  Digging 

If you happen to spot a patch of green or a damp spot in an otherwise dry creek bed, this is an indicator that water lies close to the surface. Dig a hole and if it fills up with water, scoop out the liquid with your cooking pot.  Alternatively, place a shirt or a bandana into the hole, let it soak up the moisture and wring it directly into your mouth.

F.  Condensation

Techniques such as the solar still and tying a plastic bag tightly around the end of a living, leafy branch, are known as condensation traps. Whilst ultimately effective, they produce very little return relative to the amount of time you need to wait (up to 500ml of water in 24 hours). They should be employed only as a last resort after all other avenues have been exhausted.

8 Replies to “Hydration Tips for Hikers”

  1. Visiting with Nimblewill Nomad last fall, he told me that when he walks in dry, desert environments and has to travel long distances between water sources, he keeps his mouth closed when he walks, breathing completely through his nose. He says by doing so, he loses much less water by breathing. Have you every heard that or tried that?

    1. Hi Gerry,

      Good point; you do lose less water when breathing through the nose, rather than the mouth. Nostril breathing has a lot of other benefits as well, and is something I first started focusing on when I started practicing yoga.



  2. Excellent advice and thank you! Oh yeah, great Abbey quote. I just finished reading Desert Solitaire 3 days ago. Like you, he has seen and done many fantastic things.

  3. Sorry but I think a lot of this guidance is well intentioned but outdated.

    You don’t need to force fluids. Best practice is to drink when you are thirsty not on a timer.

    If you are eating salty foods probably no need for salt / Gatorade powder and you may just be adding surplus salt. If you are actually running for 8+ hours OK but endurance athlete issues are a bit unique.

    No point drinking a liter of water in one go at a rest stop as body is limited in ability to absorb water at one time and you are more likely to just make yourself sick.

    Better than physical symptoms is to watch for change in mental state. Also key indicators of dehydration are no urine output for extended period of time. Many of the symptoms you highlight sound more like heat illness.

    Agree with the need to be cognoscent of dehydration at altitude lest confused with AMS.

    1. My opinions are based on my experiences in the field. Basically what’s worked for me on the H2O front over the past few decades in a wide range of environments (see the website if you’d like details).

      Not sure if you’re a hiker, but I think you might find that when trekking 10 to 14 hours a day for extended periods in arid environments, taking in some electrolytes and upping your salt intake does help. As does drinking over the course of the entire hiking day; not just when you become thirsty as you mention. Similarly, I’ve always found that “cameling up” at water stops also assists, as it means I’ll be able to go a little further before feeling thirsty again, and thus won’t have to carry quite as much to the next refill point.

  4. I really like the part about not all water sources are equal. That is very true of stagnant water. It can be dangerous even when filtered. Great read, thanks!

  5. Hi Cam

    This is really sound advice, I see so many people set off without enough water for the day, this can lead to a dangerous situation.
    I especially like your tip of drinking half a litre of water before leaving, this is a habit I have reinforced at home by taking a bottle to bed and drinking it before I get up!
    That way whatever I’m doing I know I’m starting hydrated.

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