How to create a fresh-water solar still

A solar still provides a means to distil water using the heat of the sun. It works by extracting and purifying any available moisture.

Erecting a solar still can be a valuable survival technique if you’re stranded in the bush.

To get the job done, you’ll need a container and a sheet of plastic large enough to cover the hole you’re about to dig.

1. Dig a hole about half a metre deep and one metre wide. If the ground’s rock hard, search for an existing hole or hollow that’s in full sunlight. Place container in the centre of the hole.

2. Pack green leaves around the edge of the bowl then pour any available fluids over it.

3. Cover the hole completely with plastic and pile soil and rocks right around the edge of the plastic to totally seal up the hole.

4. Position a small stone directly above the container, so that the plastic dips in the centre.

The leaves will sweat out any fluid in them as the temperature increases. The water will then turn to steam and evaporate towards the plastic, leaving anything that is not pure water on the bottom. Condensation reforms the steam back into water droplets which will then drip down the angled plastic near the rock and into the container.

TOP TIP: You can use this method to desalinate a few litres of seawater when stranded at the beach.

For more survival tips when out in the bush, read the Australian bush survival guide.