Being involved with permaculture helps one develop a mild obsession (and that’s putting it mildly) with water. Long before I was a certified designer, just an avid reader of permaculture texts and articles, and a compulsive watcher of Geoff Lawton YouTube videos, I was looking at landscapes completely differently, with an eye that begged for contour lines and took aim at potential dam sites. I imagined this water feature connected to that one, which fed another downslope when it overflowed across a level sill, the entire countryside dotted with water storage and well-hydrated food forests.
One of the ideas I’ve always been excited about but never quite got my head around was using hard surface runoff from roads and/or polluted areas. It seemed counterintuitive to spend so much time developing natural, chemical-free permaculture sites then funnel tainted water onto them. Of course, in certain environments, any drop of water available is worthy of collection, but still… how could we? Well, I was recently watching some videos from the upcoming earthworks course with Geoff Lawton, and I finally got an answer.
We can set up natural water harvesting and filtration systems to make the most of dirty hard surface runoff, as well as provide us with both clean water and rich compost for our forest gardens.
The water catchments in this situation need to centre around soakage rather than storage. In other words, we don’t want to catch the dirty water in dams and allow the pollutants to remain in the water. Instead, we want the water to gather and soak into the landscape, where natural elements like soil and plants can begin to clean it.