Green Vegetation

Although the presence of any living vegetation is an indicator of subsurface water, the amounts of water are usually miniscule, and it is not available in sufficient quantity to justify any expenditure of energy in an attempt to dig for it. Most arid-area plants survive because their deep roots extend well below the earth’s surface to gather small quantities of water available in the soil. Although it may not be appropriate to dig for this water, the process of plant transpiration can be capitalized upon to collect a significant amount of water in a relatively short period of time. This process is described later in the chapter.

Animal Trails

Most animals require water at regular intervals, usually once a day. By observing the movement of animals, it may be possible to determine the specific location of nearby water sources. Distinct trails are developed over time by both wild and domestic animals that travel to and from water sources on a regular schedule. Pay attention to forks in animal trails because they often indicate the direction of a water source. If an animal trail forks into two trails, then it is possibly leading a person away from a source of water. Conversely, if trails come together, an individual may be walking toward a source of water or food. Even though the direction to a water source can be determined, the distance to that source may be too far for the survivor to realistically reach on foot. Birds and animals have a far greater capability to travel long distances without water than does a human. Consequently, it is usually better to stay in one place, as opposed to wandering around the desert looking for uncertain water sources.

Bird Movement

Most birds require water at least once per day. By watching their movement, especially in morning and evening hours of the day, a general direction of a water source may be determined. Once again, the urge to travel must be weighed against unknown distances and the questionable quality of water sources.

Open Water Sources

Collecting water from open sources is usually the easiest method available to the survivor. However, caution should be exercised. Lakeshores and the edges of rivers can be hazardous. Crashing waves, swift-moving water, undercut river banks, and unstable footing can all create problems. Swampy shorelines, heavy vegetation, lakes, streams, or ponds surrounded by cliffs, other difficult terrain, or unsafe ice conditions may preclude a person from getting close enough to a water source. Don’t risk life and limb trying to climb or reach the water’s edge when safer strategies can be used. Tie a line to a water bottle or container of some type and throw it or lower it into a water source from a safe location or vantage point. Because most water containers do not come with a reliable attachment point when the container is uncapped, make one by duct taping a loop of parachute cord or nylon line to the side of the water container (Figure 71-1). Do not use the retaining strap that connects the cap to the water bottle for this purpose. In many cases, this strap will break or pull free from the full bottle as it is being retrieved from the water source, resulting in loss of the bottle.

FIGURE 71-1 Attach a lanyard loop to your water bottle.

(Courtesy Peter Kummerfeldt.)

In some instances, water sources may be very muddy or silty and need filtering or settling before they can be used (Figure 71-2, online). Rivers originating from glaciers carry large amounts of “glacial flour” that should be removed before consumption (Figure 71-3). This is best accomplished by allowing the water to settle overnight and then filtering it through fabric before drinking.

FIGURE 71-3 Rivers originating from glaciers are discolored by the glacial “flour” they are carrying. This water should be allowed to settle before filtering.

(Courtesy Peter Kummerfeldt.)

FIGURE 71-2 Muddy water should be allowed to settle and then be filtered.

(Courtesy Peter Kummerfeldt.)

The water in some lakes, particularly those in the western United States, contains high concentrations of calcium carbonate and calcium bicarbonate in solution, which make the water nonpotable. Lakes of this nature are usually easy to identify because the calcium salts that are leached from the ground are deposited in the form of white powder around the perimeter of the lake as the water evaporates (Figure 71-4). Water containing high concentrations of calcium carbonate and bicarbonate tastes terrible and should not be consumed.

FIGURE 71-4 Calcium salts leached from the soil are a common sight around many western lakes.

(Courtesy Peter Kummerfeldt.)

Water collected from rivers and streams should not be considered “pure” (Figure 71-5). Giardia, Cryptosporidium, and other harmful pathogens found in water sources are not deactivated by aeration or exposure to ultraviolet rays. All water should be disinfected and purified using methods described in Chapter 67.

FIGURE 71-5 All water should be purified if possible before it is consumed.

(Courtesy Peter Kummerfeldt.)

Seeps and Springs

The quantity of water produced by seeps and springs varies tremendously. In some cases, the amount will be only a few teaspoons per hour (Figure 71-6). In other cases, gallons of water can flow from the ground in minutes (Figure 71-7, online). Where the quantities are small, the flat edge of the opening of a plastic bag can be used to scoop the water from a shallow source, or if it is flowing, to collect the water as it runs into the bag. A short piece of vinyl aquarium hose also works well for sucking water from shallow collections or to recover water from narrow cracks in the rocks.

FIGURE 71-6 Desert seep.

(Courtesy Peter Kummerfeldt.)

FIGURE 71-7 Desert spring.

(Courtesy Peter Kummerfeldt.)

Tanks

After a rain, water collects in low-lying areas and may be found long after the last storms have passed through the area (Figure 71-8). Check out any depressions, sinks, or other low places where water could gather. Remember, the presence of vegetation and animals could provide a clue to the presence of a water source. Water sources like these should be checked carefully because they are frequently contaminated with debris that has been washed into the drainage. Finding the remains of animals that have died nearby or in the water, animal droppings, or other similar contaminants necessitates boiling, the use of halogens, or a filtration system designed to disinfect water (see Chapter 67).

FIGURE 71-8 After rainfall, water can be found in desert tanks (A) and other depressions (B).

(Courtesy Peter Kummerfeldt.)

Wells

It may be possible to locate abandoned open wells from which water may be obtained. Commonly, the rope and bucket used to lift water from these wells will be missing and a person will have to improvise a means to lowering a container down into the well to retrieve the water. With a closed well, where the pump handle is present but secured, or where the water is piped to another location, it may be necessary to dismantle or damage the plumbing to access the water. This may not be possible without tools.

Windmills

Windmills that could provide a ready source of water are a common sight across North America, especially where there exists little surface water (Figure 71-9, online). Commonly, the water pumped to the surface is collected in a nearby tank or pumped directly into a trough from which livestock can drink (Figure 71-10). If this is not the case, then it may be necessary to dismantle or damage the pipes associated with the windmill to gain access to the water. Without tools, this may not be possible.

FIGURE 71-10 Water pumped from the ground by windmills may be readily available to a survivor.

(Courtesy Peter Kummerfeldt.)

FIGURE 71-9 Windmills are a common sight across the arid regions of the western United States and may provide a survivor a source of water.

(Courtesy Peter Kummerfeldt.)

Guzzlers

In arid areas, particularly in the western and southwestern United States, state wildlife agencies and conservation organizations have installed rainwater collectors called guzzlers. These water tanks can hold hundreds of gallons of water long after seasonal rains have passed (Figure 71-11). A guzzler consists of a concrete, metal, or fiberglass apron designed to gather precipitation and feed it into a holding tank, where it remains until it is consumed by thirsty animals or it evaporates.

FIGURE 71-11 A and B, Guzzlers collect and store rain water for wildlife and others in need of water.

(Courtesy Peter Kummerfeldt.)

Dew

Dew forms on clear nights when the air temperature decreases and the water held in vapor or air suspension condenses on cool metal surfaces or on vegetation. Dew can be collected as it drains from inclined surfaces on which it has formed, or it can be sponged up using an absorbent material. Campers’ towels (Figure 71-12, online) are one of the best materials for collecting dew. These highly absorbent towels quickly absorb moisture and can then be wrung out into a container or squeezed directly into a person’s mouth. A sponge is also very useful for collecting dew. Dew must be collected early in the morning before it is evaporated by the sun’s heat.

FIGURE 71-12 Campers’ towels are very useful for soaking up dew or water from shallow sources.

(Courtesy Peter Kummerfeldt.)

Rain

Rain water can be easily collected by erecting a flat surface (Figure 71-13). Water collects on the upper surfaces of any material (it doesn’t have to be waterproof) and drains to the lowest point, where it is collected.

FIGURE 71-13 A plastic bag, sheet of plastic, or other material erected as shown is a very efficient method to collect large amounts of rainwater quickly.

(Courtesy Peter Kummerfeldt.)

Snow

For a normothermic person, there is no reason not to “eat” snow as an auxiliary source of water. However, for a person close to being hypothermic or who is already hypothermic, eating snow may increase loss of body heat and exacerbate the medical condition. Survival case studies reflect that individuals who chose to eat snow frequently experienced cuts and abrasions to the mouth mucosa as a result. If snow is the only source of water on hand, and there are no alternative methods available to melt it, the snow should be collected, compacted by hand, and consumed in small enough quantities for heat within the mouth to melt the snow.

When snow falls and settles on the ground, it undergoes constant metamorphosis. During very cold periods, there may be very little moisture in the dry, fine, or wind-blown snow that accumulates on the ground. Over time, as snow accumulates, the weight of the upper layers of snow and the earth’s latent heat cause the snow closer to the ground to change. It becomes more granular in nature and more like ice than snow. When comparing equal volumes of snow, snow collected from lower levels near the ground produces more water than does snow collected near the surface (Figure 71-14). Also, less heat will be needed to convert this snow to water.

FIGURE 71-14 Melting granular snow contained in a 1-gallon zipper-lock bag (A) produced the water shown in the second picture (B).

(Courtesy Peter Kummerfeldt.)

Water Machine

The most efficient technique to convert snow into water is with what military survival schools call “a water machine” (Figure 71-15). A bag made from any available porous fabric (a T-shirt with the neck and armholes sewn shut has been used) is filled with snow and ice and hung near, but not directly over, a fire. The fire’s radiant heat melts the snow in the bag and the water runs down to the lowest point of the bag, where it drains into a container. Continually refilling the bag with snow prevents it from burning. Gallons of water can be produced quickly and safely using this method. The following are the major advantages of using the water machine method:

• Once the water machine is loaded with snow and positioned, no further action is needed until the bag needs to be filled with additional snow.

• A water machine works while a person is busy with other tasks. This saves energy.

• All the debris (e.g., leaves, grass, twigs, insects) commonly found in snow is filtered out by the cloth as the water drains into a container.

• A metal container, normally needed to melt snow over a fire, is not required when using this method.

FIGURE 71-15 Water machines are the best method to use to quickly convert snow into water.

(Courtesy Peter Kummerfeldt.)

Traditionally, snow is melted by placing it in a metal container and then applying heat (Figure 71-16, online). Several problems soon become apparent when using this method:

FIGURE 71-16 Melting snow in a pot is a very inefficient, time-consuming method of obtaining water from snow.

(Courtesy Peter Kummerfeldt.)

• The size of container is usually quite small, which limits the amount of snow that can be melted at one time.

• When heat is applied to the container, the snow directly in contact with the heat at the bottom of the container melts and is converted to steam. This steam is absorbed by the remaining snow, leaving a space in the bottom of the container. If the snow is not constantly stirred and pressed into the container, it is possible to scorch the bottom of the container and even to melt the solder used to seal the seams.

• Using this method requires constant attention.

• The water produced using this process tastes unpleasant (smoky) and often contains ash and other debris from the fire.

• The system is inefficient, increases the likelihood of being burned, and often results in damaged clothing.

Using the Sun to Melt Snow

Another method, frequently used in winter recreation, involves using a sheet of black plastic. A thin layer of snow placed on a piece of black plastic (or other dark-colored waterproof fabric) positioned in the sun will melt. The waterproof material should be positioned on an incline so that the melt water runs to the lower edge of the fabric and drains into a container (Figure 71-17).

FIGURE 71-17 The sun’s heat and a sheet of black plastic can be used to melt snow.

(Courtesy Peter Kummerfeldt.)

Digging Holes to Collect Subsurface Water

Even though water is not visible on the surface of the ground, it may still be present in the soil in sufficient quantity to be collected. Locate low-lying areas where water is most likely to have accumulated and dig down until damp layers of soil are located (Figure 71-18). Over time, water may seep into the hole, where it can be collected. If no indicators of the presence of subsurface water are present, dig a hole in the outside bend of a dry river bed. Look for a location where the centrifugal force of water flowing down river has eroded the outer bend of a curve and created a depression, where the last remnants of water flowing down the river will have accumulated.

FIGURE 71-18 Damp, low-lying areas are ideal sites to dig for water.

(Courtesy Peter Kummerfeldt.)

Beach Wells

In a coastal, saltwater environment, it is possible to locate water sources near a beach that are fresh and potable. A hole dug behind the first line of sand dunes adjacent to the high-water mark will often fill with fresh water. Fresh water, which is less dense than sea water, will collect in the hole. Holes dug in sandy soils are very tenuous and tend to cave in constantly, which may make it necessary to shore up the sides of any hole dug in sandy areas with driftwood (Figure 71-19).

FIGURE 71-19 Beach wells dug behind the first sand dunes adjacent to the shore can produce potable water.

(Right courtesy Peter Kummerfeldt.)

Solar Stills

Solar stills use a sheet of plastic and the sun’s heat to capture evaporation from soil or plants or to distill nonpotable water. The water evaporates from its source (e.g., soil, plants, or urine), condenses on the plastic sheet, and runs down the sheet into a collector, from where it is retrieved (Figure 71-20). Solar stills are not a reliable method of obtaining water in arid areas. The quantity of water produced by a solar still depends on the amount of water contained in the ground. Because desert soils tend to hold little or no water, the amount that a survivor is likely to obtain must be balanced against the amount lost in the sweating process while constructing the device. In most cases, a person will likely lose more water than can be recovered from the still. Even if a solar still is constructed in ground that is saturated with water, its productivity in relation to the amount of effort expended is still questionable. If the ground is saturated, the other methods of water procurement described here will most likely work.

FIGURE 71-20 Solar stills are not a reliable procedure for obtaining water from the ground.

Water from Vegetation

A person’s ability to collect water trapped by plants or contained within them can be a valuable aid to combating dehydration. Once again, a line must be drawn between methods that are practical and those that are more myth-based. Extracting water from a barrel cactus is a classic example of a survival “myth.” Barrel cacti have been long featured in survival literature as a reliable source of water in arid regions (Figure 71-21). Several issues make this practice very questionable. First and most important, the quantity of fluid that can be extracted from a barrel cactus is very limited. Second, the fluid that is removed is not beneficial and may in fact be detrimental to an individual’s health. Third, accessing the interior of a barrel cactus requires a substantial knife or other cutting tool. The outer skin of the cactus is very tough and covered with long spines. Barrel cactus should not be considered a source of water.

FIGURE 71-21 Barrel cacti do not contain water or water substitutes.

(Courtesy Peter Kummerfeldt.)

Water Vines

Throughout tropical and subtropical regions of the world, vines can be found that can provide a reliable supply of pure water when other sources are not available. Water-producing vines varying in size from pencil thickness up to the thickness of an adult man’s forearm can even be found throughout much of the southeastern United States. Select vines with a large diameter. The greater the thickness of the vine, the more water it is capable of producing. Because water vines are woody and tough, they can be difficult to cut. A sharp knife or, better yet, a machete, will be needed to sever the vine.

To determine whether a vine is a suitable water source, the outer layers of the vine should be deeply scored with a knife. Vines that exude a white latex sap or a colored or foul-smelling sap should be avoided. If no sap is observed, or if the sap observed is clear and without aroma, a section of the vine can be cut as a water source. A 24-inch-long piece of vine should be cut by severing the higher end first and then cutting the lower end. If the lower end is cut first, the water contained within the vine is drawn up by capillary action, and far less water will drain out by the time that the upper end is severed. This becomes apparent when the available knife is not large enough to cut through the tough vine quickly. In one test conducted in Florida by the first author, a 24- by 4-inch section of water vine produced more than 1 cup of water.

Once detached, the section of vine is held vertically, and the water contained within the vine is allowed to drain into a container (perhaps a cupped hand), where it should be further evaluated. Liquid that is colored should not be consumed. Liquid that has an unpleasant aroma, other than a faint “woody” smell, also should be discarded. A small amount of the water should be tasted. Water that has a disagreeable flavor, other than a slightly “earthy” or “woody” taste, should not be used for drinking. This source could be used to satisfy external hygiene needs. If the water is still being considered for consumption, a small amount should then be held in the mouth for a few moments to determine if there is any burning or other disagreeable sensation. If any irritating sensation occurs, the water should be discarded. Ultimately, plant liquid that looks like water, smells like water, and tastes like water can be safely consumed in large quantities without further purification (Figure 71-22).

FIGURE 71-22 A to E, Water vines contain large quantities of water that can be recovered by cutting out a 24-inch section and draining the water into a container.

(Courtesy Peter Kummerfeldt.)

Transpiration Bags

The use of clear plastic bags to enclose living vegetation and capture the moisture transpired by the leaves can be an effective method of collecting water (Figure 71-23). A plant’s survival depends on its ability to gather water from the soil. This water is passed up through the plant’s roots, stems, and branches and is finally released as water vapor back to the atmosphere through pores in the leaves. This process is called transpiration. Water vapor is captured by enclosing as much living vegetation as possible within a clear plastic bag and sealing the opening shut with a cord or duct tape. The vegetation should be given a vigorous shake before placing it in the plastic bag to remove any insects, bird droppings, or other materials that might contaminate the water. Within a short period of time, water will begin to condense on the inner surface of the bag and collect into water droplets.

FIGURE 71-23 Transpiration bag collecting the water transpired by desert willow.

(Courtesy Peter Kummerfeldt.)

Over a period of hours, the droplets accumulate and drain to the lowest point. The quantity of water obtained in this manner depends on the amount of water in the ground and the type of vegetation used. Other factors that determine water production include the amount of sunlight available, clarity of the plastic bag, and length of time the process is allowed to work. It is not uncommon to find that 2 or 3 cups of water, and sometimes much more, have accumulated over a 6- to 8-hour daylight period (Figure 71-24). This water is contamination free and does not require further purification.

Figure 71-24 Enclose a large amount of leafy vegetation in a clear plastic bag and seal the neck (A). Water transpired by the plant condenses on the inner surfaces of the bag and drains to the lowest point (B), where it can be sucked out using a piece of vinyl hose (C).

(Courtesy Peter Kummerfeldt.)

Transpiration bags do not work at night, and they do not work well when opaque or colored bags are used. The process of transpiration slows down when it becomes dark. Depending on the temperature, the plastic bag can be left in place for 2 to 3 days, at which point the leaves become damaged by the heat that develops inside the bag, causing the process to stop. The water that collects can be removed from the bag by disassembling the apparatus and pouring out the water, or by punching a small hole at the lowest point in the bag and allowing the water to drain out. Neither of these procedures is optimal because one requires that the bag be reassembled and the other necessitates repairing the hole in the plastic bag. The best way to remove the water without disturbing the bag is to insert a length of vinyl aquarium hose through the neck of the bag down to the lowest point where water will collect. The water can then be sucked out or possibly siphoned into a container. When enclosing vegetation in the plastic bag, it is advisable to place a chicken egg–sized stone in the lower corner where the water will collect. The weight of the stone creates a separation between the enclosed plant life and the water and precludes the plant saps from leaching into the water.

Using the transpiration process is a practical method of collecting water in desert areas, but it is also useful in other areas where surface water is not available. Unlike in deserts in other parts of the world, a considerable amount of vegetation is found in North American deserts. This is vegetation that can be used in the transpiration bag process. Most vegetation in desert areas is thorny, so considerable care should be taken to keep these thorns from tearing the plastic bag. Desert willow, a non-thorny shrub commonly found throughout the American southwest, is an excellent source of water. The poplar family of trees, including aspen and cottonwood, found in more temperate areas, is another good source when using this method of water procurement. Because the trees and shrubs that produce the most water are deciduous (lose their leaves in winter), the transpiration bag process is generally limited to the time of year when vegetation is in leaf.