Harvest your own rainwater to save dwindling supplies

I HAVE been following the frightening – “terrifying” may not be too strong a word – sequence of events leading to the present water situation in Cape Town and the outlook for the summer.

I am surprised that no one appears to have considered a source of fresh water which is currently going down the city’s stormwater drains, presumably into Table Bay: the rainwater running off the roofs of houses.

Here on our property in Sedgefield, we have a roof collection system, a 1hp pump and storage tanks with a capacity of 30 000 litres. This, with careful usage, provides my wife and I with adequate water for all domestic use, and only very rarely do we have to switch over to the municipal supply. (Knysna municipality, of which Sedgefield forms part, is on category 3 water restrictions). Such installations as ours are fairly common on the Garden Route.

It is 10 years since we had our system installed, so I am not au fait with current costs, but at a guess I would suppose a 30 000-litre installation would cost between R65 000 and R100 000, according to the system chosen. Each additional 5 000-litre tank – standard sizes are 5 000 to 10 000 litres – would cost about R4 000. When one considers the value of a three-bedroom suburban house, these sums aren’t unreasonable.

A drawback is that the tanks are unsightly. There are two possible solutions to this problem. The simplest is to put them in a wooden enclosure. The other is to put them in the ground. This would presumably be rather more expensive, but the tanks would not be vulnerable to vandalism.

There are two obvious advantages to such installations. The first, most obvious, is that the householder who has such a system is freed from the constraints of the emergency regulations. Once the tanks are reasonably full, say 50%, the family can enjoy proper showers and have a reasonable amount of water for all household purposes.

The second advantage, and this is probably more important, is that if a significant number of people are using rainwater for domestic purposes, a corresponding significant amount of the municipality’s dwindling supplies are not being used.

Another small benefit: once the considerable capital outlay has been made, the water is free! Is it healthy? I can only say my wife and I, plus various visitors, have been drinking rainwater for 10 years without any ill-effects. We are now 89 and 86 respectively.

There are limitations to the application of this scheme, of course. I don’t suppose it could be installed in highrise buildings or in townships. And before some class warrior accuses me of advocating something that will benefit only the prosperous, please read the second advantage I listed. I’ve only outlined my ideas here. Anyone wishing to know more or discuss it with me can email janettonyrendell@gmail.com.

Lastly, this is a “lose not an hour” situation. The installation I have described takes about a week to set up, and any firm that deals in garden irrigation systems should be able to do it. There is often rain in the Cape in November and December, so let’s get going. Tony Rendell Sedgefield