Projects – our pond

The pond started almost accidentally – our track is eroded by rain running down it, so Chris channelled the water to one side and a shallow pond formed. Next time he saw a bulldozer in the area he arranged for some earth to be scooped out and the pond deepened. Our clayey soil held the water until late spring, and life flourished. We even had some Glossy ibis appear for a short stopover during their migration. But it was sad to watch the oasis dry up and see the frog spawn left high and dry.

We dug out more earth for a natural building course in June and began to think about how to make the enlarged pond more permanent on a minimal budget. Our friends and permaculture practitioners, Andrew Zionts and David Arribas, have a small pond they made and lined with ordinary agricultural black plastic, and after seeing how full of life it is, we asked them to help us design and create a permanent pond at Casa Gaia.

We held a volunteering day on the autumn equinox and an unseasonably hot day saw a group of 30 of us sweating it out, taking turns with the digging in full sun. Following the permaculture principle of maximum return on energy use, one team wheel-barrowed the sticky clay to a shady spot where it was turned into adobe bricks by  another team, or placed in plastic lined pools containing water, to be used for the natural building course the following weekend. We dug out more earth to give the pond a better shape with more edge, and used this top soil to form a hugelkultur bed next to the mandala garden.

Andrew supervised the shaping of the pond, aiming at maximising the variety of available microclimates and ecological niches by creating different depths as well as shaping the edge. Using a simple level made from 2 sticks and a length of transparent plastic tubing filled with water, we created a narrow level top shelf to hold the plastic, a wide shallow shelf and a deep central reservoir, which will serve as retreat space in our long dry summers if we are unable to maintain the water level through grey water recycling.

The rough outline shape was created and levelled in one day, but some stages aren’t suitable for the joyful chaos of large groups, and also the clay was like rock. Rain was forecast so we left the pond for a week, and after the rain had softened the clay we finished off with the help of a smaller team of volunteers. The finishing process involved shaping a bit more, smoothing the surface and laying cardboard under the plastic, to avoid punctures. Once the plastic was in, it was time to wait for the rain to come and fill the pond… and hope that no animal decided it was a good place to play meanwhile! Chris used this time to slowly cover the entire surface of plastic with stones. This has a double function: the sun degrades agricultural black plastic over time, even through water, and the stones will slow this process down considerably. Also, as the water inevitably retreats in our long hot summers, we will see more and more stones as the level drops, rather than black plastic. In addition, the stones and accumulated mud will provide niches for wild life too. Chris placed a pipe to channel the water from the road, to limit erosion at the entrance to the pond, and also to facilitate filtering should it prove necessary.

The rain came with a vengeance with one small corner to go – we had more rain in one weekend than fell in the entire previous year, a lot of it overnight, filling the pond to over-flowing and backing up to form an unmanaged wetland! That last corner will have to wait until spring, when the level drops again. Meanwhile we are not the only ones enjoying the new pond: plants, pond skaters, frogs and birds all arrived within hours and tadpoles within days. We have already turned down offers of gold fish – we want to allow the pond to be colonised by animal life already found in the area – but we have accepted pond weed and water hyacinths, and planted papyrus and mint around the edge. The next step is to connect our grey water recycling system, so we can maintain water inflow during the long period we have with no rain – sometimes from June to September. Come back in a few months to see more photos of this developing ecosystem as we add the to the album below!

Projects - Pond

Creating a pond/Creando un estanque