Category Archives: Water

Frozen Water

Photo by Joel Casto

Photo by Joel Casto

To Do Today:

  • PT – Cardio – 2000m swim for time // Strength – Leg group

Ice and Water

Heat kills waterborne pathogens, cold does not. Purify cold water, or water under ice, obtained from lakes, streams, rivers, etc. the same as you would in a temperate environment.

Melting snow and ice is the primary method to replenish water supply in arctic environments, or at sea in extremely cold environments. However, fuel use and the task of cutting ice and melting snow is resource intense. Twice the amount of fuel is needed to melt snow than if you melt ice for the same quantity of water. Pack snow tightly in the container to be heated to increase efficiency. Also, packing a water bottle with snow that is 1/4 filled with water, and then keeping it under a parka while moving or working is an efficient way to melt snow on the go.

Sources of liquid water should be safely explored whenever possible (i.e., water from lakes or streams under ice). If digging a hole in the ice over a lake or river to obtain water, carefully do it to avoid splashing:

  • First start to axe or chop all around the hole but make very sure not to puncture the ice to the water.
  • Cut until all your hole is deep and wide enough for your bucket or water storage device.
  • Once you are near water on all sides, give a sharp blow to break the ice totally.
  • If you don’t do this, the water will seep into your hole and you may get dangerously wet while trying to enlarge the hole to collect water.

After cutting a hole over fresh water, the hole should be covered to prevent refreezing (if using the source more than once).

Frozen salt water

Sea ice generally becomes fresh during the period between its formation and the end of the first summer thereafter. If during freezing weather you are ever in a position where you have no other source of water but salt water, contain small amounts of brine and allow ice to form in it. The slush and any remaining liquid should then be removed. The ice will be fresh enough to use in an emergency. On a larger scale, ocean ice looses salt so rapidly that ice over 1 year old is nearly fresh. Ice formed 2 or more years old can not be distinguished as far as taste goes from river ice unless waves have been breaking over it recently or spray has been dousing it. Melted hollow otherwise will usually be found to contain ample fresh water. Salted ice is grey and opaque whereas unsalted ice is bluish and of crystal color.

Information contained on this website is for general information and educational purposes only. Please refer to our Disclaimer and Terms and Conditions before attempting any technique described herein.

Water From Plants

Photo by Cpl. Aaron Hostutler

Photo by Cpl. Aaron Hostutler

To Do Today:

  • PT – Cardio – 1hr Swim // Strength – Rest

Cautions and Warnings

There are certain precautions and a few danger signs with regard to vegetable fluids. If the fluid is milky or red or colored in any way it must be regarded as dangerous, not only to drink but also to the skin (the one exception known is the Barrel Cactus in the US).

Many of the milky saps, except those of the ficus family which contain latex or a natural rubber, are extremely poisonous. The milky sap of many weeds can poison the skin and form bad sores and if allowed to get into the eyes cause blindness. With all vegetable sources of fluid even though the water itself is clear, taste it first and if tasteless, or almost tasteless/flavorless, it is generally safe to drink

Also, fluids or vegetable “drinking water” cannot be kept for more than 24 hours. The fluid starts to ferment and spoil if stored and might be dangerous to drink in this condition. Lastly, the nature of a plant judged by the properties of its foliage is no guide for the drinkability of the fluid which are its sap, for example, the Eucalyptus.


Collecting Water From Plants

In tropical areas, look for plants with hollow or concave sections that collect moisture. Many plants have leaves which are cup-like in shape and collect pools of water in their leaves; be observant. Many palm varieties grow leaves directly from the trunk, and some ferns and bromelaides (from the pineapple family/small plants which grow on the side of other, larger, trees), often have leaves which are designed to catch rain and channel it down to the base of the leaf where it meets the trunk. The water pools there so that the tree can slowly absorb it.  One example of this is the Traveler’s Tree (Ravenala Madagascariensis). This comes from the banana family and can hold up to 1–2 liters of water which pools between the leaf stalks where they attach to the tree.

In desert areas, palms are a good indication that water is nearby, generally within several feet of the base of the tree. Reed grass is also a sound sign that moisture is near. However in general it is futile to search water near desert plants, for this one has already taken it, so use
the plant itself from its roots which you dig, pull and section off.

Leaning tree method

Cloth absorbs rain/dew running down tree and drips into container:


Banana plants

Banana plants hold water in their trunk. This can be accessed by either slicing off the trunk at about 1ft from the ground or by inserting a tap into the trunk. To tap a banana plant, take an 8in length of bamboo, about the diameter if your thumb, ensuring that it is hollow all the way through. Sharpen one end with your knife and insert the bamboo tap firmly into the banana plant at about a 70 deg angle to the trunk of the plant. This will allow the water to start running out of the trunk and down through the tap. Create a water trap underneath the end of the tap, by placing a large leaf or piece of plastic over a depression in the ground for the water to drip into and leave it for a few hours before returning to have a drink. The water may taste like green bananas but it is drinkable.


Eucalyptus leaves are heavily impregnated with oils of Eucalyptus and in many cases poisonous to human beings. However, its sap is generally a drinkable fluid easily collected from the branches or roots. Eucalyptus fluid is entirely free from essential oils and does not taste or smell of Eucalyptus. Its roots measure from 12 to 25 meters, and radiate deeply. Pull the roots, cut into sections, remove the bark, and sap will sweat at both ends. Place containers at the ends to collect the drinkable fluid.

Water trees

Other water bearing trees are the Boabab tree (often known as the tree of life), found in Australia, Africa and Madagascar. All hold water in the trunk. Avoid milky sap. Tap before dark. Let sap stop running and harden during the daytime. These trees produce most water at night. For evasion situations, bore into the roots and collect water out of sight.


In early spring, walnut, maple, birch, and hickory trees can all serve as sources of water. To get the fluid, you simply tap the tree, as maple-syrup makers do, by boring a half-inch or quarter-inch hole into the trunk with a knife or sharp rock, inserting a hollow reed, and collecting the thin sap in a bark or log cup.

Alternatively, you can cut through the bark with diagonal slashes. Make sure that you cut into the sap wood, or cambium, that lies just under the bark and that you don’t kill the tree by cutting all the way around it.

Since water gathered by this method contains a high concentration of sugar, drinking large amounts of it can cause an upset stomach or cramps. For the same reason, the liquid tends to spoil when it’s not consumed soon.

Sycamore trees can be tapped in the same manner as can the hardwoods mentioned above. The water from this tree, however, can be harvested any time of year except the dead of winter and, since it doesn’t contain much sugar, can be consumed in quantity or stored for a few days.


All common species of North American thistle can provide water. Bull thistle yields the most fluid. To get the juice, simply peel the thorns off the young stems and leaves and eat the watery food-like celery. Since thistles supply only a meager portion of liquid, though, they’re best used to quench a burning thirst or to keep you going until other water sources can be found.


Some vines in tropical and subtropical environments can yield a reasonable supply of drinking water, like the Liana or Monkey rope. The general characteristics of such vines are rough bark and off-shoots of about 1-2in thickness. Always be weary of plants with a sticky, milky sap as this is usually poisonous. Vines are no exception so observe this when trying various vines for water.

To get water from a water-bearing vine, simply cut a deep notch in the vine, as high up as you can, (it is important to cut the top first or else the vine will act as a vacuum and suck the water back up the vine) then cut it completely through at the base. At this point the water should begin to run out. Check that it is not sticky & milky and then collect the water in a container or let it run/drip straight into your mouth. Do not put the vine in your mouth as some vines can irritate your lips.

When the water has stopped flowing, cut a section off the bottom end to release water still inside the main vine. Repeat this until all water has been released. General rules:

  • Cut bark – do not use milky sap.
  • If juice is clear and water like, cut as large a piece of vine as possible, cutting the top first
  • Pour into hand to check smell, color, and taste to determine if drinkable.
  • Do not touch vine to lips.
  • When water flow stops, cut off 6 inches of opposite end, water will flow again.


Bamboo will usually yield an excellent supply of water in the hollow stems, between the joints. Water can be located by tapping the stem about 7-10 cm (3-4 inches) above a joint. If you hear a dull sound then they will most likely have water inside. You can shake the stems and listen for water inside too. Aim for thick stem bamboo. Water is most likely to collect in older, yellower stems. When you locate water, cut a notch just above the bottom joint and the water will run out freely. This water will be clean and good to drink as-is.


  • Shake and listen for water
  • Bore hole at bottom of section to obtain the water
  • Cut out entire section to carry with you
  • Filter and purify


In the tropics or near a beach, coconuts are a source of water. Drink in moderation as coconut milk is a laxative.


Whilst most cacti have a fluid content, not all cacti yield fluid which is safe to drink. Some cacti can be very poisonous; like the the giant Saquarro cactus found in the California and Arizona regions of North America and in Mexico. On the other hand, the Barrel cactus is an exception to the “Avoid milky sap ” rule. This life saver can yield around a liter (2 pints or 33oz) of drinkable sticky milky sap. The best way to handle cacti is to cut off a piece to expose the inner flesh, then either cut chunks out pf the center to mash or suck the moisture out, or to cut and mash the flesh, while still in the base, till there is enough liquid to collect or drink then repeat.

Always be very careful when handling cacti as you really don’t want to get the spines stuck in your skin as they can be almost impossible (especially the fine ones) to get out in a survival situation and if left, they can cause weeping sores which can quickly turn septic.

Cactus fruits such as prickly pears can also provide liquid. The liquid in some cacti can be tasteless and sour in other varieties.

Transpiration Method

Water can be obtained by placing clear plastic bags over the leafy branch of a non-poisonous tree and securing the end of the branch. Ensure there are no holes in the bag (seal these with black tape, band-aids, etc.). The action of the sun on the plastic will cause water to be drawn from the leaves and run to the lowest part of the bag. Do not disturb the bag to collect the water, use a straw or tubing. The leaves will continue to produce water as the roots draw it from the ground.


The water should be drained off every two hours and stored. If this is not done the leaves may stop producing water. The heavy concentration of moisture laden air reduces the effectiveness of the sun. If there are no large trees in the area, you can break up clumps of grass or small bushes and place them inside the bag. The same effect will take place. If this is done the foliage will have to be replaced at regular intervals when water production is reduced.


  • The water bag must be clear.
  • Collected water will taste like the plant smells.
  • Do not use poisonous/toxic plants in any still or bag.
  • Ensure that the bags receive maximum sunshine at all times.
  • Test exposed roots for water content. Soft pulpy roots will yield the greatest amount of liquid for less effort.

Tree Roots

For plant sources of water in arid areas, the best volume is generally obtained by excavating surface roots. They can be discovered and cut close to the plant, lifted and pulled. Roots must be cut in 3-4 feet lengths for draining. Many fail to get liquid to flow because they do not cut the stalk or root into lengths. Unless the segments are made, fluid will not flow and the conclusion is that the root, branch or vine is without moisture. In general water is more plentiful from plant roots in gullies than on ridges.

In the early morning before the heat of the day, the roots from certain trees such as the boab, kurrajong, wattle, some gums and others, can be cut into short lengths, stood end on with their thickest ends down in a container allowing the fluid to drain. It is best to use roots that are easily obtained with a minimum of effort. The ideal location for this is in creek beds and washouts where parts of the roots are already exposed or near the surface.

It is possible to get water from the roots of some trees by removing the bark, cutting shavings into a pile and pulping the root shavings with rocks then squeezing the water out of the pulp and letting the water drip into your mouth.

Some trees will yield more water than others. Some trees with a higher water content are: the blood wood, the water tree and the desert oak; all found in Australia.

This method works if you are desperate but uses a lot of energy for the yield.

Information contained on this website is for general information and educational purposes only. Please refer to our Disclaimer and Terms and Conditions before attempting any technique described herein.

Terrain Indicators of Water

Photo by James Stevens

Photo by James Stevens

To Do Today:

  • PT – Cardio – Run 30 min, max distance // Strength – Body weight: 5 sets of:  1) strict pull-ups, max reps; Squats x 20; Push-ups x 15; Lunges x 10/leg // Core – Plank: 3 sets of side-lying bridge, 45-60 sec side/30 sec rest between sides/Run 400m between core sets. 2 min max rest between sets.

Terrain Indicators of Water

When no surface water is available, look for hidden surface sources and ground water. Indicators include an abundance of lush green vegetation, drainage areas, and low-lying areas.


  • Valleys and Low areas. Follow the terrain lower to find natural depressions where water may collect or flow. In a sand dune belt, any available water will be found beneath the original valley floor at the edge of dunes.
  • Creek beds. Look at foot of concave bank areas. Creek beds are easily discernible in dry areas because of the relatively green vegetation and taller trees following the course of the creek. Unless there has been recent rain in the area the creek bed will probably be quite dry. You may be lucky enough to locate damp sand or mud at the bends of the creek or by digging in the creek bed at a likely spot. Water can be extracted from the damp sand or mud by soaking a rag in soil and wringing out the water into a container. The exposed tree roots in the creek bed can be cut in lengths and drained of their fluid early in the morning. To reduce the risk of infection, any surface water must be boiled.
  • Rock Formations. Look at foot of cliffs or the bottom of rock outcroppings. If there is any water seepage from the ground, it is usually to be found near rock formations, where the terrain is rugged and undulating. Rocky areas are also ideal for rain catchment. Rain soaks very quickly into the soil, whereas it can lie in pools on a rocky surface for as long as two weeks. Look under rick formations, fissures, and in crevices. Carry flexible tubing to reach deeper into rock depressions or use soaking rag.  A zip-lock bag is useful for scooping water from shallow pools.
  • Salt Lakes and Wadi’s. Look in nearest depression behind first dune away from dry/wet/salty lake. After rain has fallen, the top 3 mm of a salt lake is fresh water. It can be siphoned off by using a grass straw or tubing.
  • Windmills. Erected in many remote farming/ranching stations in order to provide lift service to wells, dams and soaks. These can be seen from a long distance and usually have animal tracks leading to them. Check to see that the water at these mills has not gone salty.
  • Water seepage. Look for damp surface sand. Natural springs and soft rock erosion areas (slopes, banks, etc.).
  • Coastal Areas. Sea water may only be consumed after it has been distilled: Dig hole deep enough to allow water to seep in; obtain rocks, build fire, heat rocks; drop hot rocks in water; hold cloth over hole to absorb steam; wring water from cloth. An alternate method can be used if a container or bark pot is available: Fill container or pot with seawater; build fire and boil water to produce steam; hold cloth over container to absorb steam; wring water from cloth. Water may also be found in coastal areas by digging behind the first group of sand dunes: Dig high up on the beach above the tide mark. It will taste brackish and should only be used in small quantities.


Note on vehicles

If traveling in a vehicle, extreme temperature variations between night and day may cause condensation on metal surfaces. Use cloth to absorb water, then wring water from cloth. Purification or distillation should be conducted for water collected from metal surfaces.

Information contained on this website is for general information and educational purposes only. Please refer to our Disclaimer and Terms and Conditions before attempting any technique described herein.