At Save the Rain, we pride ourselves on appropriate technology. We use locally available materials, aiming always for simplicity, sustainability, and as little waste as possible.
Of course, one of our main ingredients is cement: construction of a 3,500-liter residential rainwater harvesting system uses 12 bags apiece. Cement needs to dry slowly and evenly so it doesn’t crack, and part of our seven-day build includes a whole day to allow the structure to cure correctly. After construction, the tanks continue curing for four weeks. We splash it with water and cover it in plastic sheeting to make sure it sets solidly enough to last 200 years.
Though the sheeting here is necessary, and we reuse it as many times as we can, we’ve always wondered how we might move away from plastic. We use permaculture to create our greenhouses and farm — so, we decided to extend that thinking to our building too.
One of permaculture’s key principles is all about closing the loop, by connecting unmet needs with unused resources. Our need? To move away from plastic. Our surplus resource? Empty cement bags. A lightbulb moment happened while talking with our material supplier: we began sewing these sacks together to create a cover that fits perfectly over each curing tank.
Each cover can be used multiple times, and each build generates more sacks to stitch. We’ve cut out plastic, made trash into treasure, and provided a tailor with steady, salaried work — all in the name of saving the rain.
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