Bushwalkers usually collect water from natural sources like creeks, rivers, lakes, and soaks they find on the route or a short way off it. These supplies change with season and rainfall, and some are more reliable than others – often those rivers that are fed by smaller creeks.

Care must be taken to choose sources that are reliable, and backups must be in place in areas where water availability is variable. Sometimes, bushwalkers might have to carry enough water supplies to get to a backup water source or walk out. In some regions with high numbers of visitors or unreliable water supplies, tanks have been provided by management.

Natural water sources include creeks, rivers, lakes, and soaks that run over the ground, natural collection points such as cave drips and tree crevices, as well as water sources that run deep below the ground.

Where to look:

• Check the map to determine the lay of the land. Dotted blue lines represent seasonal (non-perennial) creeks, whereas solid blue lines are more permanent (perennial) waterways, although these can also run dry. Examine the topology and watch out for steep edges or cliffs that are impassable. Small catchments are more likely to be a clean source or water, whereas larger creeks with more sources of input are more likely to be running. But beware of relying too heavily upon a map for information: water courses can change, and constructed features such as mines and farms can dramatically affect water flow in natural areas surrounding them.
• Places where water naturally pools such as low-lying areas, valleys or gullies.
• Always go downhill. Water follows gravity downwards, so when looking for water follow the lay of the land downhill. Gullies that appear dry higher up often start to flow at lower elevations. Often, following a gully downwards can lead to water.
• Search rock crevices, tree crotches, rock pools, drips from cave overhangs, or other natural water catchments where rainwater may have collected.
• Patches of healthy green vegetation, plants typically found near water (e.g. wattles, she-oaks) and damp or muddy ground. These all indicate some source of water which may be possible to access by digging.
• The presence of animals: mammals, insect and birds tend to stick close to water sources, and these are often places where animal tracks converge. Birds often circle watering holes, and the flight direction can be used to detect water sources. The formation of seed-eating birds changes as they approach water from a random clustering to an ordered and neat formation.

Ideally, water should be collected from clean sources, that flow from pristine natural areas, but if there is doubt, then treat water. Treatments for water sources contaminated with pathogens include boiling, chemical or UV treatments.

Pathogen contamination can come from:

• Farms: Animal faeces
• Popular campsites and huts with many visitors: human faeces

Water contaminated with toxins, fertilisers and heavy metals cannot be treated in the field, and bushwalkers should avoid these water sources. Examples of this kind of contamination include:

• Mines and factories (e.g. above the Wolgan River)
• Pesticide and fertiliser run-off from farms (e.g. Cox’s River downstream from the Megalong Valley farms)
• Towns that are above walking areas, such as in the Blue Mountains

Handy tips:

• Check with local land managers or authorities about current water conditions on the track. Find out as much information before heading out into the bush.
• Share information about water sources with other walkers on the track.
• When filling up at water sources, try to drink as much as possible (if the water can be treated and drunk immediately), before filling water containers as this maximises the time needed between water sources.
• Listen out for flowing water. Keeping an ear out for trickling water is an easy way of locating a water source. Although traveling down a gully can be an effective way of finding water, it can be challenging due to the thicker scrub and vines that tend to grow there. Sometimes it’s easier to follow a parallel ridge downhill and listen for flowing water and only duck into the gully occasionally to check for water.

Special environments:

• Desert: never walk in desert conditions without being confident about water availability. Water is rarely found running on the surface, but can be dug for in a dry river bed: preferably choose a section where the river is under shade for most of the day and dig into the outside of the bend. Digging can yield some water, particularly if there has been flash flooding and water has been stored beneath the surface. However, digging for water can be energy intensive and yield poor results, so apply caution. It may be better to conserve energy resources and focus on doing things that maximise the chance of rescue.
• Alpine environments tend to have high rainfall where water is often trickling close to the surface. Hence, it’s possible to find running water at high elevations. Snow can be melted and used as drinking water.
• Coastal: Care must be taken to select fresh water sources as drinking salt water leads to dehydration and higher concentrations of salt than the human body can handle. Potable water can be found above the high tide mark, where fresh water and salt water sources cannot mix. A small cascade above the high tide mark is a good place to start looking for water. Large bodies of water near oceans can have salt water for some distance upstream, so the chances of finding potable water increase dramatically when looking for a smaller source, perhaps one that feeds that larger body of water. According to “The 10 Bushcraft Books” by Richard Graves:

“Fresh water can always be found along the sea coast by digging behind the wind-blown sandhills which back most ocean beaches. These sandhills trap rain water, and it floats on top of the heavier salt water which filters in from the ocean. Sandhill wells must be only deep enough to uncover the top inch or two (2.5 or 5 cm) of water. If dug deeper, salt water will be encountered and the water from the well may be brackish and undrinkable. It will be noticed, too, that the water in these wells rises and falls slightly with the tides. These sand wells are a completely reliable source of water all over the world. When digging it is necessary to revet the sides with brushwood, otherwise the sand will fall into the well.”

“On coastal areas where cliffs fall into a sea a careful search along the lower edges of the cliff will generally disclose soaks or small springs. These in general follow a fault in the rock formation and frequently are evident by a lush growth of ferns and mosses.”

Warnings:

• Avoid stagnant or coloured water sources, as these are more likely to be contaminated.
• Avoid drinking urine until it is a life or death scenario. First, extinguish all other sources of clean or dirty water.

Hunts and formal campsites usually have taps and rainwater tanks, however, it’s not always easy to get information on the current condition of the tank or how full it is. Tanks are susceptible to damage from wild weather, corrosion and contamination from animals (faeces or dead animals falling in), and water can become stagnant is not refilled and emptied regularly. Also, how full a tank is depends on precipitation and the number of users. Low rainfall, a high number of users or both can lead to a low tank.

The best way to get information on tank conditions is to ask someone else that has visited the site recently (preferably within the last fortnight). Alternatively, national parks websites may give current information on water availability at population sites, but a short phone call to the appropriate land manager or ranger is likely to be more reliable. Beware of relying on maps that show constructed water sources: in general, printed maps are made using data that is several years old, and infrastructure out in natural places can quickly change.

Since the water in tanks comes from the runoff over rooftops and guttering, it’s a good idea to treat it because these structures are likely to collect animal dropping and other natural waste. Likewise, tap water in campgrounds is usually pumped from a nearby water source that is likely to be contaminated from the toileting facilities nearby.

Tank water is a precious resource and bushwalkers must take care not to waste it. Use tank water for drinking and cooking, but avoid using it for excessive dishwashing or showering. For example, when washing billies use a small amount of water, and perhaps use that water to wash other items. There’s also the problem of poor hygiene, with people washing their hands and touching the spout of the water tank. Certainly, it should be kept clean, but if the only available water is from a tank, then wash with as little water as possible, and never directly from or near the tank; use a personal water container, at a distance.

Lastly, if relying on a constructed water source (e.g. tank, reservoir), take into account that parts break. Apart from just wearing out, alpine environments are not kind to tanks, pipes and taps, which can burst when water freezes. In summer, there’s not a lot that can be done in the field if a water tank with a solid lid has a seized tap. Best to find another water source and report any damage to the park manager as soon as possible.

With some skill and effort, water can also be obtained by engineering constructed tools to collect rain water or transpiration from plants, and also by breaking open tree roots or eating certain plants (e.g. succulent plants).

Rainwater run-off
Rainwater run-off is an easy way to obtain water: just leave a few billies out overnight and after a moderate rainfall, they’ll be full in the morning. If collection containers are limited, it’s possible to rig up the outer fly of the tent so that water drains more quickly and directly into a billy or pot. Likewise, collected rain run-off from huts is an effective way of collecting water, although most huts have a rainwater tank that is more efficient.

Snowmelt
With some patience, snow can be melted to produce drinking water providing the group has sufficient gas and time to do so. In most cases, snow should be melted and the water boiled to treat for contamination by pathogens.

Dew
Sufficient dew may collect overnight in areas where there are few or no trees so that it can be possible to collect enough of this water to survive. Run a rag or tufts of grass over the dew on the ground and squeeze out the moisture to drink. While this technique doesn’t produce much water, it may assist in emergency scenarios.

Plants
Pig Weed, Pig Face (Carpobrotus) and Ice Plant (Parakylia) contain enough moisture to drink from. It’s also possible to obtain water from tree roots, although the process is undoubtedly damaging to the tree, and only to be used in emergency situations.

Transpiration
Plants transpire water throughout the day as they absorb sunlight and convert it to energy via photosynthesis. It’s possible to collect this water by tying a bag over the leaves of a plant.

Moisture condensation
A solar still can be used to collect water by using the heat of the sun to evaporate, cool and collect it. Using the sun to collect water is an emergency technique that takes substantial setup but can yield between 0.5-2.5 litres depending on conditions.

Natural water sources can be perennial (flow all year round) or non-perennial (intermittent). Whether a natural water source contains water depends on physical variables like temperature, rainfall and humidity. A bushwalking group looking for a water source has to decide on how likely a watercourse is to contain water, if the water is in sufficient quantity to collect, if the water is accessible (i.e. not down a steep embankment or with a wall of blackberries), and ideally, not needing treatment.

A crucial natural variable for the amount of water availability in the bush is the amount of recent rainfall, which varies with:

1. Location: Coastal and northern Australia and Tasmania experience higher levels of rainfall than central and western Australia.
   
   Therefore, walking the Overland Track in Tasmania is less likely to present water issues than the Larapinta Trail in the Northern Territory.
2. Season: Australia contains both temperate, tropical and arid regions that have different rainfall regimes. In general, the northern parts of the country have summer rains, and the Southern have winter rains. The east coast has moist temperate conditions with hot summers, but thunderstorms with rainfall are common during the summer months too. Cooler months mean less evaporation of potable water sources.
   
   In general, rainfall across Australia is low and seasonal with many water courses only appearing after rainfall.
3. El Niño and La Niña Phenomena: The air pressure index between Tahiti and Darwin is used to calculated the Southern Oscillation Index (SOI). El Niño is characterised by a strongly negative index, often leading to lower winter and spring rainfall in eastern Australia, and a weaker monsoon up north. By contrast, La Niña is characterised by a strongly positive index, with higher winter and spring rainfall in eastern Australia and higher rainfall during the tropical wet season.

Other important factors are:

1. Altitude: water flows downhill and is more likely to collect at lower altitudes than higher ones.
2. Area of the catchment: the larger the catchment area, the more likely the source is to contain water because it has a larger area feeding into it.
3. Soil type: soil absorbs water at different rates depending on the porosity and permeability of the ground. Hence, the total amount of groundwater available and where other water sources can surface in that environment is a function of the soil type there.

Global warming is leading to drier conditions, and availability is changing and decreasing in some places[note]Letcher, T.M., Climate change: observed impacts on planet Earth. 2015: Elsevier[/note].

Adequate planning before a bushwalking trip allows the group to devise ways to manage obstacles like sheer cliffs, blackberries, and thick scrub that may obstruct water sources. In general, going along the riverbank may lead to easier access. The group may find a secondary source that has less flow but is accessible.

In practical terms, predicting water accessibility and availability comes down to good knowledge of the land, experience with how local weather patterns affect flow, and an understanding of how clean that water source is. While this knowledge can take years to accumulate, a good starting point is talking to land managers and other people who have recently walked in that area.

Compared to finding a water source, collecting water is usually the easy part. Water collected from swift flowing sources must be taken with care, and different techniques can be used in streams with low flow to get water efficiently.

A creek, stream or river makes water collection easy. Avoid stagnant water by aiming to collect from flowing sections. Hold the water container in the flowing water and the water bottle should fill.

Sometime near campsites, where water sources risk becoming contaminated by the sheer volume of visitors toileting in the catchment area then go upstream for a few minutes, cross the river on rocks, and get water from a stream that has only dense bush above.

Choose a collection point where the water source is running and is easy to reach with a water bottle. Avoid loose rocks or cliff edges, as these can be difficult to traverse up and down. Aim for flat, stable banks, and for fast flowing water make sure to be stable enough not to fall in. Sometimes, it might be worth traveling 5-10 mins further up or downstream to find a safe collection point.

Still water sources like soak or lakes are also great collection sources, however, if at all possible, avoid using water that’s flowing very slowly or is stagnant. Stagnant water is a collection point for toxic runoff and laden with decaying plant and animal matter and associated microorganisms. Avoid water sources with excessive algal growth and foam on the surface as these are signs of contamination from agricultural or industrial runoff. That said, if the group is out of options, then stagnant water may be better than nothing. It’s important to weigh up the risks of dehydration and illness carefully. In these cases, fill water container deep underneath the surface of the water to avoid the nasties on top and treat the water. In short, there’s no easy way when water sources are scarce; it’s better to have more reliable sources.

Collecting water from swift water sources can be extremely dangerous: there’s a serious risk of falling in and getting swept away. There’s also the risk that the bank may collapse. Try to find a spot that has a gentle slope to the water; leaning over a drop is awkward, even if it’s not high. Better to find a slower flowing side creek to fill from, or a still eddy on the edge of the river. Likewise, care must be taken when collecting water in cold or snowy conditions: ice on river banks can make edges slippery, and bushwalkers are vulnerable.

Lastly, taken into account environmental considerations when collecting water: avoid creating new paths to water sources by encouraging the group to spread out as they reach the water source. Care should be taken not to damage the river bank as soil and vegetation are prone to erosion.

In dry regions, or after a period of low rainfall, small water sources may run very slowly making them much harder to find and collect. These sources are hidden gems but can take some time and patience to fill water containers.

There are a few ways to manage water sources with low flows or that are awkward to reach. If the flow is strong but shallow, consider making a hollow or dam and using a mug to scoop out water. Note that some small creeks have a lot of soil and sediment build up due to the low flow. Collecting from sources with high sediment can be challenging as the sediment can get stirred around and end up in the water container. One way to reduce the amount of sediment in the collection process is to put the mug or container into the water source gently with the opening upstream, just enough to let water go in but not the sediment.

Another way to fill a container of water from a natural water source is to get a curled piece of bark and use that as a pipe. Once this is set up, let it flow until sediment stops. It helps to wedge the bark at the top with rocks or sticks to keep it in place.

For subsurface rivers with no clear stream of water, it’s still possible to collect water from the wet sand or earth. Place a flattened wine cask or groundsheet in the sand with slight V-shape towards the middle, and the edge of the ‘V’ poking out. Hopefully, there will be a flow of water from the V, enough for the night.

Accidental sediment collection is typical from water sources with low flow and has the unfortunate side effect of making some forms of water treatment less effective. Course filtering at collection using a piece of clothing or coffee filter paper can help.

There are many types of water collection devices, each with their own merits and flaws depending on the water flow, need to treat the water, and collection time.

• Soft plastic and hard shell water bottles: these include old soft drink bottles and reusable hard plastic water bottles. Wide-mouthed containers are easier to fill from low flow water sources, but can be harder to drink from. Narrow-mouthed bottles take longer to fill up: using a spare mug to assist fill up can significantly speed things up.
• Collapsible water bottles: these water bottles can be rolled up and stored at low volume in the backpack. They are slower and harder to fill up, are at greater risk from puncture than a hard-shell PET water bottle, and harder to drink from because they lack rigidity. However, they make good backups and enable the user to greater increase their capacity to collect and carry water without much extra weight or volume in their pack. Again, using a spare mug to assist fill up can significantly speed things up.
• Billies: easy and quick to collect water from due to the large opening but hard to carry far without spilling water, so only used when retrieving water from a source close to camp.
• Pack tap or old goon bag. Lightweight and effective way to collect and carry large volumes of water, particularly when not camping directly next to a water source. The nozzle is broad enough to fill quickly from reasonably flowing water sources, but for smaller flows using a mug to assist is easier. These bladders are not designed to be directly drunk from but rather to be decanted into a more drinkable water container. Carrying a bladder like this is an excellent backup to increase the carrying capacity of water in the group dramatically.
• Yabby straw: A yabbie straw, or yabbie tube, is a piece of flexible tube used as a straw to suck water for drinking from anywhere that would be difficult to get water out by other means. Effective in places where water is ok to drink untreated and water sources are regular enough that the drinker can satisfy their water needs without having to collect water.

Back at camp, have a system in place to separate treated from untreated water. Dedicate a 10L tap pack of untreated water for the group to use to wash hands, cooking containers and so on.

Sometimes a water source is right next to the track or campsite, but other times access can be more involved. If going more than a short distance to get water, always take another person and leave details of the intended route with the rest of the group.

Although it’s not necessary to carry an entire overnight pack when looking for water, consider taking a few essential items as a fallback in case of unexpected delay:

• Map and compass
• Torch if it’s late in the day
• Warm layer or blizzard jacket
• First aid kit
• PLB in remote areas
• Snacks

On multiday trips, it can be useful to carry an additional small, lightweight daypack for these such occasions. Alternatively, leave overnight gear at a base camp and only carry essential gear items in the overnight pack: using a proper pack with good straps is best when collecting and moving large volumes of water (e.g. more than 5L to take back to base camp).

Rules when for looking for water:

• Don’t split up: it can be tempting to split up and search a wider area. Don’t, always stay within earshot.
• Navigation: if exploring off the track down a gully for a water source, have someone in the group that has sufficient off-track navigation experience to ensure that they can return safely to camp.
• Be realistic: set a reasonable timeframe to search for water before heading back to camp to reassess. If the group does not find a water source, reconsider where to camp or when to walk out.
• Watch for sunset: keep a watch on the sun and if it’s starting to get dark before there are clear signs of water, stop and reassess the situation. It may be better to head back to camp, conserve water supplies and walk out at first light the next day.
• If necessary, treat water before drinking.