Fishponds

 My first hands-on exposure to fishponds was when I was in my early teens and my dad had proudly brought home some plastic sheeting that he had salvaged from one of his construction sites. We had a long and narrow garden, quite well under control at the top of the property with large sliding doors opening onto a lawn. Lower down the site, it became progressively wilder, with many indigenous trees planted by my parents and rough veld grass.

My dad's scheme for the plastic was for the very highest part of the garden, where there was quite an outcrop of natural rock. The plan was to build a series of small fishponds that would naturally discharge into each other down the slope and would water the rockery below when the system overflowed. The idea was to keep it technically very simple, as it would have been disruptive and expensive to introduce pumps and irrigation through the natural rock.

Our first task was to make some rough measurements, bearing in mind the size and shape of the plastic damp-proof membrane that we were upcycling. We could then start excavating pockets of soil from between the rocks, dislodging and repositioning some of them to create our cascade. We also collected some natural rock from the rest of the property to be able to build up the sides in places and create water spouts from one level to the next.

Fortunately our rocks were relatively smooth, but in some of the ponds, as a precaution to protect the plastic from being punctured, we made a "daga" of one part cement to six parts of builders' sand, mixed with just enough water to form a paste to pack into the crevices and to dress over the pointy pieces of rock. We then roughly cut out the plastic to the various shapes of the ponds, making sure that there was enough for the sides. I remember weighting down the plastic with some of the loose stones and leaving the sheeting for several days to be shaped by the heat of the sun. My dad, always conscious of climate and weather, made sure that we started this project after he was sure that the last rains of summer were over.

A pond formed with natural materials
Creative Commons Licensed: https://pxhere.com/en/photo/1242958

That weekend, we did the trickiest part of the project - grouting in a layer of large stones and small rocks to create a border for each pond, and ensuring that the plastic was well secured beneath the edging rocks. The moment of truth came the following weekend - when the cement grout had completely set and cured, we could start filling the ponds with a hosepipe. I remember a few anxious moments, and some rapid remedial work with grout and smaller stones where the water level was not high enough.

Then came the creative part - filling the ponds with water-plants and replanting around the outside of each with water-loving plants such as arum lilies. One of the water-plants we discovered at the plant nursery was called water lettuce. a real boon in a system that had no pump or filtration, as it clarified the water, providing a suitable environment for the fish which my mom and brother had chosen. 

Our new water feature attracted a wide variety of birds that we had never seen in our garden before, and was soon populated by a family of noisy frogs. It became the favourite spot for our cats, fortunately none of which had the co-ordination to catch any of the fish. By locating it quite far from the house, we avoided one of the biggest pitfalls of a garden water feature in southern Africa - mosquitoes - which we managed to keep at a distance from bedrooms and outdoor terraces that we used in the evenings.

This turned out to be just the pilot project - my dad was so enthusiastic about the results that we went on to construct a very modest wetland in the wilder part of the garden. The maintenance for both water features was very undemanding, in spite of no pumps or filters - they just needed topping up a couple of times a month in the dry winters and for teh rest, our choice of vegetation did the rest of the work.