If the terrible 2016 drought and the current crises in both the Western and Eastern Cape have taught us anything, it’s that water is indeed South Africa’s most precious resource. Mother Nature’s warning couldn’t be any clearer – use your water wisely and conserve it as best possible, or face the possibility of it running out completely. Moreover, it certainly isn’t inappropriate to point out that saving water also means saving money.
First things first
To keep things simple, we’re only going to look at two inexpensive water saving household fittings: flowrate regulated showerheads and flowrate regulated taps. Also, our example household consists of a (happy) family of four, who each shower for ten minutes a day and, collectively, use their taps for 30 minutes a day (seven and a half minutes each).
The flowrate of a normal shower head is upwards of 15 litres per minute (15 l/m), while, for example, the Ellies Storm Shower Head lowers this to 8 l/m. This means that a normal shower that lasts ten minutes will consume 150 l, and amongst 4 people, 600 l per day. In a year, the water usage is therefore 219 000 l (219 kilolitres). Using the Ellies head, however, cuts the 600 l down to 320 l daily, and to 116 800 l per year. This is an impressive reduction of up to 102 200 l (or 46.7 percent saving).
Whereas items like water efficient appliances, dual flush toilets, garden watering timers and grey water recycling systems will save an enormous amount of water, we're going to look at tap flowrate regulators as an example to keep things as straightforward as we can.
Taps expel water at the same rate as showers (15 l/m), but the flowrate regulators can reduce this to less than 3 l/m. If each person in the household uses a normal tap for seven and a half minutes a day, the total will be 450 l per day and 164 250 l a year. In comparison, a flowrate regulated tap will only use 90 l per day and 32 850 l per year. Our happy family will save 131 400 l per year, reducing their tap water usage by 80 percent.
This number would increase if our family simply installed a Jojo Tank to harvest rainwater.
Some more food for thought
This means that in a normal situation, between their taps and shower, our happy family uses a total of 383 250 l a year, whereas, if they use the flowrate regulator fittings, this usage drops to 149 650 l. That’s a difference of 233 600 l of precious water (a 61 percent reduction). Not bad.
But now let’s imagine that 250 000 households in South Africa each save this amount of water: that’s 58 400 000 000 l (i.e. 58.4 billion litres) per year. Over a period of twenty years, that amounts to 1.168 trillion litres in a water vulnerable country.
To put that figure into perspective, if the current daily usage of Cape Town is around 500 million litres, an extra 1 trillion litres would delay day zero by 2 000 days. Wow.
But what about those precious rands and cents?
As water tariffs differ across municipalities and have varying rising block tariff structures, we can't produce figures that are definitive; but in an effort to illustrate the principle with an example, we’ll refer to the 2018/19 City of Johannesburg water tariffs (published here). Additionally, please note that these are somewhat “back-of-the-envelope” calculations, and shouldn’t be taken as being the final word on the matter.
The 233.6 kl saving distributed over 12 months amounts to a massive 19.47 kl per month. If our household is initially using 40 kl per month, their current bill will come to about R869.48. As their water saving will drop them into a lower tariff bracket, and as they use 19.47 kl less, their new bill should sit at approximately, R286.68. Over a year, that’s a saving of (again, roughly) 67 percent, which equates to R6 989.28.
Over 10 years, that’s a whopping R69 892.80 in 2018 prices if both tariff brackets increase at exactly the same rate as overall inflation. This, however, is quite unlikely as the current trend has been to increase prices in the higher kilolitre brackets at a rate exceeding those of the lower kilolitre brackets. In short, this means that that over time, it is entirely plausible that the difference between the two monthly costs mentioned in this article will rise above the 67 percent we approximated; which is to say that year on year savings may increase substantially over the long run. That's a really good reason to cut down on water consumption - and keep it at the lowest possible level - in order to save even more money.
At the end of the day, either way you look at it, a R69k+ saving is not only not bad, it’s actually pretty kickass.