- Dig a bowl-shaped hole about 1 meter across and 60 centimeters deep.
- Dig a sump in the center of the hole. The sump’s depth and perimeter will depend on the size of the container that you have to place in it. The bottom of the sump should allow the container to stand upright.
- Anchor the tubing to the container’s bottom by forming a loose overhand knot in the tubing.
- Place the container upright in the sump.
- Extend the unanchored end of the tubing up, over, and beyond the lip of the hole.
- Place the plastic sheet over the hole, covering its edges with soil to hold it in place.
- Place a rock in the center of the plastic sheet.
- Lower the plastic sheet into the hole until it is about 40 centimeters below ground level. It now forms an inverted cone with the rock at its apex. Make sure that the cone’s apex is directly over your container. Also make sure the plastic cone does not touch the sides of the hole because the earth will absorb the condensed water.
- Put more soil on the edges of the plastic to hold it securely in place and to prevent the loss of moisture.
- Plug the tube when not in use so that the moisture will not evaporate.
You can drink water without disturbing the still by using the tube as a straw.
You may want to use plants in the hole as a moisture source. If so, dig out additional soil from the sides of the hole to form a slope on which to place the plants. Then proceed as above.
If polluted water is your only moisture source, dig a small trough outside the hole about 25 centimeters from the still’s lip (see diagram below). Dig the trough about 25 centimeters deep and 8 centimeters wide. Pour the polluted water in the trough. Be sure you do not spill any polluted water around the rim of the hole where the plastic sheet touches the soil. The trough holds the polluted water and the soil filters it as the still draws it. The water then condenses on the plastic and drains into the container. This process works extremely well when your only water source is salt water.
Finding surface water, especially during the dry season in Africa, can be an almost impossible task. The above technique of harvesting water is, from experience, relatively easy to do although quantities collected may be quite low. In a static survival situation, assuming you have the components on hand, you can construct a few of these stills (be sure to protect the stills from animals by surrounding them with thorns). Dry riverbeds are usually a good find in a survival situation as there is water beneath the sand. Animals such as elephant are very good at digging in the right areas; they often dig a water hole in a riverbed even when there’s surface water nearby (the water seeping through the sand is generally cleaner and cooler). Dig your own hole in the riverbed, slightly upstream and away from holes dug by animals to avoid drinking contaminated water. Water from rivers in wilderness areas is not necessarily safe to drink due to upstream pollution by man (e.g. Olifants River is highly contaminated). If possible, boil the water or treat with a sterilizing agent before drinking. There are certain African and exotic plant species that can be used for natural water purification. Survival situations are not necessarily confined to wilderness areas. A city can be plunged into a survival situation due to natural- and man-made disasters (including deliberate contamination and/or destruction of water supplies by enemy troops, see War and Water). Collecting rain water off your roof and storing it in water tanks may ensure your short- to medium-term survival in such a situation. Contact Water Rhapsody (Mpumalanga) for all your rainwater harvesting requirements.
See Part 2 on this subject.