While planting a wisteria by the chicken coup with Adam and Ricardo, I witnessed micro erosion event take place. The wisteria was planted inside a circular dam and while filling it with water a portion of the wall collapsed followed by a steady stream of water pouring out. At first I lazily tried to build up the wall with my shovel. That held for about 10 seconds, then the wall collapsed again. Next, I bent down on my hands and knees and observed the situation closely. I could see the water flowing out, taking the wall with it. I placed a few stones to slow down the flow. I then found where some clay had collected and I quickly scooped some up to patch the leak by building up the wall and compacting the outside, then I added a layer of dry sand to harden the wall. It took several attempts but I finally repaired the wall. Subsequently I built a swale to direct overflow of water along the chicken fence line to encourage weed growth for chicken grazing. I then built another swale uphill from the wisteria to divert any rainwater to our vine. But I digress…
All this micro erosion control got me thinking, how would such a leak be contained at a much larger scale? What I observed from the event with the wisteria is that unless there are hands available to subdue water pressure and provide compaction to the outer wall, the water washes away anything put to patch the leak. Rocks, of course, would not wash away, but there is too much area in between them to actually hold water. Furthermore, this risks sending pressure to the edges of the collapsed area causing a greater whole to form in the wall of the dam.
The solution I came up with takes just two step if the supplies are on hand. I imagine that stones with at least a 6 inch layer of clay around them could be dropped in front of a leak followed by a massive amount of sand. Dumping the clay covered rocks would slow the water pressure, and allow the clay to fill in the area in between the rocks. The sand would act as an underwater drying agent which would give the clay a chance to set without being washed away by the water pressure.
I believe that this strategy could save a lot of time, money and water. But more importantly it was a fun exercise of observation, questioning and experimentation. The real discovery, more than any dam repair technology, is simply the value of playing with earth and water. Many of the major problems of our times are rooted in mismanagement of our land-water intersections. We have built a society based on agricultural and extractive industrial models which are massively ignorant towards the tending towards the long term viability of the land they manage. I believe this is due, in part, to a basic lack of knowledge. This is best addressed through hands on learning. The more we understand the relationship between water and earth, the better we can care for it. That’s why playing with mud is so important. Exploring dams, ponds, swales and sediment traps in the garden, doing micro earthworks, gives all people the opportunity to gain awareness of our place in the world and how we can make it more beautiful. I encourage you to play with mud as much as possible.