”CRITICAL WATER SHORTAGE! DAMS AT 11.2%,” reads a roadside sign that usually notifies drivers of accidents. In the once-leafy suburbs of Cape Town, South Africa — where I live — it’s now considered a sin to have a green lawn or take a luxurious soak in the tub. These days I shower (two minutes, no more) with buckets at my feet, which, once full, are used to flush the loo. And my kids bathe in 2 inches of water, which is then diverted onto a flower bed. Cape Town has a Mediterranean climate, but the combination of an expanding population (3.7 million in the metro area, growing at 2.6 percent per year), an extended dry cycle and a lack of municipal foresight has brought the situation to a dramatic and desiccated head.
Against this backdrop, graywater recycling companies have sprung up in Cape Town and other parched areas of South Africa like daisies after a desert cloudburst (if only). One expert estimates that home recycling installations in the city have jumped from around 300 per year in 2005 to 6,000 in 2017. Gray water is the water that comes out of baths, showers, hand basins and washing machines — about 33 percent of the water used in an average house with a yard and more than 50 percent in an apartment without a garden. Instead of ending up in sewers, it’s repurposed for garden irrigation (cheap and easy), flushing toilets (slightly more complicated and expensive) and taking showers and doing laundry (pricey and complex). According to local installers, a basic garden irrigation system for an average family home in Cape Town costs about $1,000 and cuts consumption by around 30 percent, for annual savings of $150.