Finding, purifying and conserving water in an emergency
In the case of emergency, like vehicle breakdown away from human assistance, it is quite possible to find and purify water using little or no equipment.
- depending upon your surrounding, certain indicators can be used to locate natural water reserves. For example the presence of vegetation in the desert is a sure sign of underground water, which can be accessed either by digging or via the vegetation itself. Animals also make good indicators of nearby water. The presence of bees is a sure sign that there will be water within a couple of miles or so, and a steady line of ants climbing a tree trunk is a good sign that there is a water reservoir stored in the tree. Grain-eating birds like finches and pigeons are always found near water and the regular trails of larger animals will often lead to water.
Water in vegetation
- certain types of vegetation can provide hidden reserves of water. Tree roots and branches, and vines can be cut into lengths and the sap drained to provide reasonable drinking water. The quantity and palatability of sap varies from tree to tree but in all cases the roots, branches or vines must be cut into smaller lengths or the sap will not run freely. Other plants like some cactus, banana trees and plantain, pitcher plant and others will yield stores of water either hidden within the vegetation or collected from rainwater. Vegetation gives of water vapour, which can be collected by either tying a plastic bag over living vegetation or filling it with freshly cut vegetation and sealing the bag. Water will condense on the inside of the bag and run to the bottom. Try to keep the vegetation from touching the sides of the bag.
Water from rain, dew, snow and seawater
- water can also be obtained by collecting rainwater, any waterproof sheet can be used to collect and channel the rainwater into a suitable container. Dew can be collected at dawn by wiping a cloth through long grass and then wringing it into a container. A solar still is an easy method of collecting water and uses the principal of temperature difference to condense out water present in the surrounding air. It can be made by digging a hole about a metre wide and half a metre deep and placing a container in the centre of the hole. Cover the hole with a sheet of plastic anchored around the edge with stones. Place one stone on the sheet directly above the container as this will allow water condensing on the inside of the plastic sheet to run down and drip into the container. This method works best where there is a large difference in temperature like in the desert. Slowly melting snow will provide good drinking water and seawater can be made drinkable by boiling it in a container and covering it with several layers of cloth, which will capture and condense the vapour ready to be wrung out into another container.
- stagnant or polluted water can be made clean and safe by filtering it through charcoal (time permitting) and if possible boiling it as well. Very muddy water can be cleaned by adding a pinch of alum, which will flocculate and precipitate the clay particles (takes up to 12 hours) or by filtering it through any closely woven fabric like a sock, cotton shirt or felt.
Preventing water loss
- If you are short of water there are a number of things you can do to help prevent water loss. Rest in the shade but not on the hot ground and stay covered up during the heat of the day as this will help prevent water loss through sweating. Work or move only at night. Breathe through you nose not your mouth and do not smoke. Eat only what you need to survive, avoiding fatty foods and alcohol (both require a lot of water to digest) and don't let your water run out before you think of searching for more.