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How Long Can You Go Without Water?

The rule of threes states that you can only survive three days without water under normal circumstances.  In this article, we will discuss how long you can go without water and how dehydration will affect you.  We will also cover how you can find water quickly if you are already dehydrated.

It is so easy to end up fighting for your life when you spend time in the wilderness.  It just takes a wrong turn, a slip on a slick rock, or an unexpected storm and you are stuck.  You are now forced to evaluate your current situation and decide how to act.

First and foremost, you never panic.  Just stop what you are doing, take a deep breath, and think it through.  What resources did you bring with you?  What natural resources do you have?  Can you reach help?  Does anyone know where you are?  Can you hike to safety or do you need to stay put and signal for help?  These are all questions you need to ask yourself.

Once you come up with a plan, you must decide how to spend your time.  No matter what path you take, there are a few resources that you will need to survive.  The four pillars of survival are food, water, fire, and shelter.  We already discussed how long you can go without food in a previous article and will cover fire and shelter later.  Water is our topic for this article.

Why is Water Important?’

The human body is comprised of about 60% water when properly hydrated.  This means that you need to work to stay hydrated, or your body will shut down.  Water makes your joints work better, it makes your organs run more smoothly, and it makes your brain function better. Water is also needed for the digestion of food, so if you plan to eat anything you will need water.

Dehydration is the second most common reason why people die in survival situations.  There have been several times I was stuck in the wilderness and dehydration nearly ended me.  Unfortunately, dehydration will make it harder to function long before it kills you. On my very first survival challenge, I spent all of the first day building my shelter.  It was about 80F outside at noon, and the sun was beating down.

I went to get water from the pond to drink, but it clogged my water filter.  I used my iodine tablets to purify the water, but this meant waiting 30 minutes. I was not purifying and drinking water fast enough to keep up with my dehydration.  I started getting dizzy and seeing spots.  I was thirsty but was still sweating.  Then the cramps set in.  I had been working with a machete all day cutting dry grasses, and both forearms and hands cramped up.  I could barely use my hands at this point.  All I could do was drink water and rest in the shade until the cramps eased up.

Dehydration can also make it impossible to get to safety.  A couple of years back I attempted a high desert challenge in SW Colorado.  The rangers pointed out a canyon that sometimes has puddles of water from recent rain.  They told me I should not need climbing gear but warned that there was only one person covering 117,000 acres of land.  They said that I was on my own if I got into trouble in the canyon.

I drove out to Yellowjacket Canyon, but the drop-in was way too steep to attempt without climbing gear.  I was forced to drop into an adjacent canyon which I knew nothing about.  I made it down the cliff and followed a dry creek bed at the base of the canyon.  It was obvious that there was no water in this canyon.  I also had already emptied my canteen.

After several miles of hiking, I had to decide if I was going to keep going and hope I found water or turn back and try to make it to my vehicle.  I made camp and got a few hours of sleep before deciding to head back to my vehicle. There was maybe a 10-15% chance that I could find water if I kept going, but I was dead if I was wrong.  I hiked back to the cliff and started climbing back up.  With a 50 lb pack on my back and weak from dehydration, I barely had the strength to make it back out.  This is why water is important.

How Long Can You Go Without Water?

As stated before, the simple answer is that you can go three days without water under normal circumstances.  However, there are lots of things happening in a survival scenario that are not normal.  You will be burning way more water from your body when in a wilderness survival situation. You are going to be in the sun all day, often facing high winds and extreme temperatures.  In most cases, you will be shivering all night.

You will also be working much harder than you would on a normal day at home.  This is going to burn up more water.  Most people burn three to four times as many calories when surviving versus a normal day.  Logic would state that they would use up three to four times as much water as well.

Any illness or injury will cause you to use up more water. Any time you eat you will use up water for digestion.  Always avoid large amounts of sugar, caffeine, tobacco, or alcohol as they will dehydrate you further.  Many prescription medications will dehydrate you, but you will have to decide if the medication is vital for survival. You also must factor in the general physical condition of the person to determine how long they can go without water.

The other variable to consider is secondary accidents or issues.  When you get dehydrated, you often get weak or light-headed.  You can become very pale, and your heart will race and palpitate.  You can be confused or might even collapse. While all of this is going on, it would be easy to fall and hit your head or slip with your machete and cut yourself.

When it comes down to it, there is no rock-solid answer to this question.  If you are dealing with a person that is not in great health, they are working all day in the sun, and they are a smoker and a drinker, they might not even make it one full day without water.  If you are dealing with a marathon runner that is sitting in the shade, they might make it more than three days.  There are all kinds of amazing stories of people stranded in the desert or in a lifeboat and making it weeks without water.  The point it that water is important, and you should have a plan to drink water regularly in the wild.

How Much Water Do I Need?

This is again going to vary from person to person.  The more you weigh, the more water you should consume per day.  Most people say that 1-1.5 Gallons of water per day is ideal under normal circumstances.  There are those words again.  When surviving, this number will be much higher.

I completed a long-distance challenge about five years ago on which I hiked 31 miles off-trail in the Ozark Mountains over 3.5 days with just a small backpack and minimal gear.  I brought no water with me but brought my filter bottle.  I was hiking about 10 miles a day plus setting up camp and collecting food, water, and firewood.  I pushed myself to drink about three gallons of water per day.  I was still severely dehydrated when I was finished with my challenge.

Signs, Symptoms, and Treatment

Some common signs of dehydration are headache, chills, excessive sweating, rapid heartbeat, lightheadedness, dizziness, seeing spots, weakness, dry mouth, and eventually sweating will completely stop.  I have been severely dehydrated dozens of times and have been hospitalized several of those times.  It is nothing to mess around with.

The biggest difference you will notice when dehydrated is that you get tired or winded much faster than normal.  When hydrated I can normally hike about three miles with a full pack before I need a break.  When dehydrated, that might only be half a mile.  I find that I must stop to catch my breath constantly, and sometimes I even need to lie down for a minute.  This makes it tough to get much done in a survival scenario.

Standard treatment at the ER for dehydration is to give you IV fluids.  It has been pretty normal for me to need two Liters of fluids before they would release me.  If you cannot get to the ER, you will just need to slowly sip room temperature water in the shade.  Relax and try to get to a spot with a breeze.  Get a cloth wet and wrap it around the front of your neck to bring down your internal body temperature. Dehydration goes hand in hand with hyperthermia or heat stress.  You often must treat both to control either of them.

How Can You Quickly Find Water?

Depending on the environment in which you find yourself, there are a few quick ways to get water.  In tropical or jungle climates, this would be to find coconuts or to build a rain catchment system.  Often in jungle or tropical areas, it will rain daily or almost daily.  If you build a rain catchment system, you do not need to filter the water.  Coconuts are filled with water that is full of electrolytes.  Just be careful not to drink too much as it can make you sick.

Water vines can be found in deciduous forests and in jungles.  These are thick vines that run from the forest floor to the canopy.  If you cut through the vine, water should stream out of the top half.  This is safe to drink.  In the desert, you can use prickly pear cactus.  These spiny plants are full of moisture if you remove the spines.  This can also make you sick if you eat too much.

In snowy climates, you must be very careful about your internal body temperature.  The only thing that will kill you faster than dehydration is hypothermia.  If you have a good fire and shelter to stay warm and are getting dehydrated, you can melt ice.  Snow is 90% air and 10% water, whereas ice is 90% water and 10% ice.  If you absolutely must, you can eat ice or snow but it will drop your body temperature.

Springs are always a nice find as the earth does all of the filtering for you.  Springs can be found in many different environments.  If the water is coming straight out of the ground and it does not smell funny, you should be okay to drink it.  A funny smell can mean nasty mineral deposits. Carrying a backpack water filter with you is an essential piece of gear when you will be out in the wilderness and potentially facing survival situations. They Filter out practically all harmful microbes and elements from water. They won’t always guarantee to get rid of smells from water, but in a survival situation that’s the least of your worries.

In general, you can just follow the terrain downhill to find water.  Water always flows down, so the lower the elevation is the more likely you are to find water.  You can also look for areas where the trees and bushes are greener as they likely have more moisture. Even a dry creek bed can eventually lead you to a water source.

Closing remarks

How long you survive without water really depends on your level of preparedness.  That being said, no matter how long you think you can survive you should always have a plan for water.  If you did not bring much water with you, you should know where other water sources are.  Be sure you monitor how much water you are drinking and purify it if needed.  Know the signs of dehydration and be ready to take action if you start going downhill.  In the end, you don’t really want to find out exactly how long you can survive without water if you can avoid it.

1 thought on “How Long Can You Go Without Water?”

  1. I always get edgy when I read articles like this because the advice is sometimes questionable. Another reason is that people tend to blow it off. The “it won’t happen to me” syndrome.
    Here’s another way to describe the necessity for water when you are on foot, hiking cross country and in wilderness areas: If you become dehydrated and cannot access a source of water then you will become immobilized. If you are immobilized, you will effectively become a delirious lump in the brush, unable to seek help. What might have been a Search and Rescue mission becomes, instead, a Search and Recovery mission, the purpose of which is to find and transport your body to the nearest morgue.

    Your article omits any reference to the incredibly hostile environments of the Southwest Deserts. Anyone that thinks they can survive for three days without water in the desert (regardless how physically fit they think they are) is deluding themselves. The odds are much greater that you will be dead within 24 hours. Add high desert temperatures and the potential for hypothermia, and you can lower your survival prospects to just a few hours.
    Survival Rules:
    1. Waiting until you are lost, stranded, injured or dehydrated is not the time to develop a plan.
    2. Always let someone know specifically where you are going and when you will return.
    3. If they have not heard from you by the specified time, they should be calling the Sherriff’s Department.
    4. Know with absolute certainty where you will be able to access water while on foot. If you don’t know, find out.
    5. Carry more water with you than you think you will need.
    6. Have even more water in your vehicle.
    7. Become acclimated and physically fit before you attempt wilderness treks.

    I’ve been backpacking in the desert when it was 110 degrees, but I have spent most of my life in desert climes and a significant portion of it outdoors. The desert is littered with the bones of people who were not fit to be there, who became lost or were abandoned by smuggling guides. The two principal causes of death are dehydration and hypothermia.


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