I’ve been thinking about the economics behind rain water storage primarily intended for irrigation.
Gauteng gets plenty rain threw summer, so filling a 5 kl Jojo is pretty easy even if your catchment area isn’t that big.
Now since we get plenty rain, we don’t use much water for irrigation during the rain season, just look at your water bill summer vs winter.
Come end of the rain season you have a full Jojo, but how long will that water last on a house with a big garden, a week, less, maybe a bit more?
So now your Jojo is empty and it will only rain again in 6 months, this is the 6 months in which you actually need irrigation water for your garden since it rains for the other 6 months of the year.
Simple answer is get more tanks to carry you threw winter, yes sure but at R5k a pop. How much municipal water can you buy for R5k, or pump for R5k if you have a borehole?
Plus remember the R5k only buys you a 5 kl tank which only adds a week and you ideally want 6 months worth of water, so you need 120 kl of storage, that’s R120,000 just for tanks, then you need the space, the pumps etc.
Is my thinking correct if I say catching rain water for later use doesn’t make economic sense at all, that people just do it to feel good about themselves, that they are saving water or saving the planet whatever?
There is of course also the emergency factor, if the taps run dry, but again, how far will 5 kl of water really get you if the brown stuff really hits the fan?