Flinders Ranges, South Australia

Safe drinking water

Adequate drinking water is essential on any trip. Sufficient water can easily be carried for a day walk. On overnight and longer walks, potable water must be found along the route.

During trip planning consider the availability of potable water and try to get current information on the condition of expected water sources. Tanks can be damaged, and previously reliable natural water sources are being adversely affected by climate change, bushfires and the damage caused by hooved feral animals; deer, horses and goats. 

It is not possible to determine just by looking at water that it is safe to drink. So a means of water treatment needs to be carried.

Drinking contaminated water can cause serious illness that can have long term effects. A lack of drinking water will cause dehydration and serious heat-related illness.

Illness during a trip may result in a medical emergency.  After the trip, medical attention should be sought for an illness where contaminated water may be the cause.

Planning water requirements

Consider:

  • Water weighs 1 kg per litre so it is prohibitively heavy to carry any substantial quantity. Hence, there is a need on most overnight trips to get safe drinking water along the way. 
  • Minimum daily water requirements in cool conditions is around 2.5–3 litres per person. This rises to two or three times this amount in hot conditions, or when undertaking strenuous activity.
  • For a dry overnight camp, at least 3-4 litres per person is required.
  • In hot conditions, dehydration and heat-related illness is a serious risk so water requirements need to be anticipated carefully.
  • Some bushwalks have tank water available. Check with land managers prior to the trip to ensure the tank is currently functional.
  • Putting in water drops ahead of the trip to make a particular trip feasible. After the trip water containers must be collected.

Collecting water

Look for:

  • Flowing water as it’s less likely to harbour pathogens.
  • Calm water in a lake or pool which has less sediment and is easier to filter and purify.
  • Clean packed snow. Icy snow contains more water than the equivalent volume of fresh  snow. When collecting snow for water, a small amount of water in the bottle or pot aids thawing.
  • Collect water from the surface and away from the edge and shallow parts of water sources. Some contaminants, such as giardia cysts, are heavy and sink and pathogens can occur in larger numbers along a lake shore or river bank.

Avoid:

  • Areas at or downstream of animal activity – e.g. faeces, ground disturbance, tracks, etc.
  • Areas polluted by people
  • Downstream of huts and campsites
  • Sedimented or brackish water, foam or scum
  • Discoloured snow
  • Collecting after heavy rain. Wait before collecting water as runoff increases bacterial loads and muddies the water.

Types of water contamination

There is a wide variety of water contaminants. The dangers posed by and best methods of treating them vary significantly. The following are the main contamination types.

Dissolved materials

  • Brackish water is unpleasant to drink. It can be made more palatable with powdered drink flavours and is masked in cooked food.
  • Salty water is unsafe to drink. It is not practical to remove salt with a portable device.
  • Some water sources contain tannin from vegetation, giving water a brown colour (e.g. as found in Tasmania). Tannin is harmless but it may taste.
  • Bore water for stock (e.g. as found in the Flinders Ranges) may have a high mineral content that makes it unsuitable for drinking by humans.

Suspended materials

Suspended natural materials include soil, clay and plant matter. These contaminants pose a low threat.

Hazardous suspended materials

Blue-green algae (Cyanobacteria)

  • Algal blooms can pose a significant health risk as some species release toxins.
  • Some toxins may persist in the water for months.
  • Toxins affect people when ingested, inhaled or skin contact is made.
  • Some slow flowing rivers are susceptible to major algal blooms, particularly if there is nutrient runoff from agricultural land and during droughts.
  • Contamination can be detected by the colour of the water, scums or unpleasant, pungent odours (musty) and tastes (earthy).
  • Algal blooms are often green or blue-green, but they can also be white, brown, blue, yellow or red. All coloured blooms must be treated as potentially toxic and water collection avoided.

Parasites, bacteria and viruses

  • Giardia is endemic in some streams and lakes. Symptoms include diarrhoea and flatulence and can occur 10–14 days after contamination.
  • Cryptosporidium is spread by contamination of water sources with faeces, producing similar symptoms to Giardia.
  • E. coli can produce diarrhoea, vomiting and other stomach symptoms and is a significant threat to health. Contamination is common near high-use huts, ski resorts, towns and urban areas where runoff enters bushland.
  • Viruses (e.g. hepatitis A, rotavirus, norovirus) are very small so can pass through some commercial filters.

Pollution

  • Chemicals such as pesticides, herbicides, fertilizer, heavy metals, fire retardant (after bushfires).
  • Microplastics

See also

References and external links