Making a soak, an Indigenous Australian method for water filtration

Waramanu yurramaagu, or ‘making a soak,’ is a traditional Indigenous Australian technique for filtering and purifying water. It entails creating a soak or waterhole in sandy or porous soil near a river or creek.

Yindjibarndi educator Irene Hayes dedicates herself to bridging the gap between Western science and Indigenous knowledge. She shares her experience, a process she learned from her mother, in this video from CSIRO, Australia’s national science agency.

“You have to dig down to the water table and insert the suitable container to collect the water flowing through the natural filtration in the soil or in the riverbed. Traditionally, you’ll probably just use like flat rocks in the river that you can thing and just hold the side out from caving in. And then once you’ve done that, then you get all this water running in. “

“But it’ll be all dirty and thing from where you’ve disturbed the soil. So it’ll get all like brown and yucky and you’ve got to get a pannikin or a mug or something and just keep emptying all that water out and then eventually it’ll sort of come clean…

“And then when you’ve got it as clean as you want, like gotten rid of all that dirty water, you just leave it to settle for a while and you’ll see it filling up with the clean water then. Then you can get a drink.”

This long-used practice is effective in natural settings due to its reliance on filtration properties of sandy or porous soil, percolation through soil layers driven by gravity and capillary action, adsorption and absorption of contaminants by soil particles, preservation of aquatic habitats, and alignments with sustainable water management.

It’s important to note that effectiveness depends on soil composition, water quality, and environmental conditions. In populated city areas or former industrial sites, highly contaminated water and soil can be an issue. Learn about a given area before using this method.

Watch more videos about water, including:
• What is groundwater?
• How are scientists harvesting water from thin air?
• Can Namib Desert beetles help us solve our drought problems?
• How do trees transport water from roots to leaves?
• Why can’t engineers control rivers?
• Why is water one of the weirdest things in the universe?

Bonus: The word Indigenous, a CBC Kids News explainer.