Minimum water requirements
Experience suggests that the minimum daily water requirement in cool conditions is at least 2.5 - 3 litres per person per day, which rises to two or three times this amount in hot conditions, or when undertaking strenuous activity. Most bushwalkers seem to require around 3–4 litres per person for a ‘dry’ overnight camp.
When you consider that water weighs 1 kg per litre, plus the weight of the container, it is clear that any substantial quantity of water is prohibitively heavy to carry. Hence, there is a need on most trips to have access to safe drinking water along the way. Unfortunately, many available sources of water are unsuitable for immediate drinking without treatment. Reasons for this include progressive development of many bushwalking and skitouring areas, activities of other users of the bush, and thoughtless actions by many bushwalkers, skitourers and campers.