Causes of water scarcity are compared using two models; one which is bigger and better, the Texas way, and the other harvesting the rain and storing it on-site as is done in Bermuda.
It is beyond dispute that conventional water-resource development in SA, and in fact the whole planet, is becoming increasingly constrained with new dam sites being scarce and few worldwide being built. Reports say these large reservoirs cause up to 40% loss of biodiversity.
With this in mind, we are faced with two models of development. One which is “bigger and better” and very capital and technologically challenging. I’ll call it the Texas stereotype. And the other smaller, far less costly, and using local-resources; the Bermuda design.
Bermuda is an island roughly double the size of Hilton, the village where I live, situated about 1000km off the East Coast of the USA. Its annual rainfall is rather higher, 1400mm compared to our 1000mm pa.
But unlike KZN, Bermuda has no streams, rivers or dams. Every home collects its water supply from the rain that they harvest and store in underground reservoirs.
By law, at least 80% of every domestic home’s roof must be guttered; and every square metre of that catchment area shall have an underground reservoir of storage capacity of 379 litres.
How does that work out?
A 100m2 roof must have 80 square metres available for harvesting the rain, and a reservoir of 80x379 litres = 30 kl. That would keep 10 South Africans very comfortably off with unrestricted water for domestic and garden use; at the end of the dry season, depending on how careful residents were, there could be a shortage.
The Bermuda website has this to say. “The rain is one of the purest sources available and nears distilled water in its purity. Its quality almost always exceeds that from a well."
Furthermore it is subjected to fewer pollutants, such as cesspit-recharge and pesticides that may contaminate groundwater. Once rain comes into contact with a roof or catchment surface though, the risk of defilement significantly increases.
According to the World Health Organisation the basic need for clean water is 20 litres per day, intermediate access is 50 l, and optimal amount 100 per person.
So a RDP house with a roof area of 50m2, fully-guttered, could supply 250 people with their basic needs, 100 folk with an intermediate supply, and 50 with an optimal amount of water in an average summer month; but none for the garden or in the dry season.
Our model is six RDP houses with a total roof area of about 250m2, sharing one communal underground reservoir, 5m in diameter and 2m deep; the cost would be around R50,000. In theory it could supply 250 people with optimal water during the rainfall months. Allowing for the dry season and water for gardening it would easily sustain say 60 people with more than adequate year-round.
The KZN premier has been roundly criticised for his Texas-model master plan for the province for many reasons which I won’t discuss; R150 billion over the next 10 to 15 years.
That amount of money would build 3,000,000 small underground reservoirs, supplying 18 million people with ample water with no need for reticulation, using the Bermuda-model.
A team of 10 men could build the reservoir in 2 weeks, say 20 per year. That means it would take 150,000 teams of ten labourers to build 3 million reservoirs, amply supplying 18,000,000 people with as much water as they wanted, using local materials.
So, what’s it to be Mr Zikalala? R150 billion for the grandiose Texas model, huge dams and vast electricity-thirsty desalination plants; pump-storage schemes, more Water Boards, and immense reticulation challenges? Or the Bermuda model providing work for 150,000 teams of 10 men, local sand, brick, and cement? Is bigger always better?
Obviously these figures are optimal and one can shoot many holes in the scheme. But the principal remains valid. Even if the Texas model is more desirable, which it isn’t in my opinion, can we actually afford it? Would it not be better to provide work for a huge number of people, using local materials?
Our reservoir has fallen short for only two months in nine years. Compared to Day Zero in the Cape a few years back, imminent in Gqeberha (Port Elizabeth) and the Great Jozi water outage in 2021 we have no hesitation in recommending that we all plan to become resilient in the face of the challenges faced by central and local government; clearly there is worse to come.
Causes of water scarcity arise mainly from poor planning. I have nicknamed this little beauty the Real Preston.
And this is one of chief causes of water scarcity; totally ignoring the gift from the heavens. One might even call it a sin.
When browsing use right click and "Open Link in New Tab" or you may get a bad gateway signal.
Our newsletter is entitled "create a cyan zone" at your home, preserving both yourself, the family and friends, and Mother Earth for future generations. We promise not to spam you with daily emails promoting various products. You may get an occasional nudge to buy one of my books!
Here are the back issues.
Did you find this page interesting? How about forwarding it to a friend, or book and food junkie; or, better still, a Facebook or Twitter tick would help.
56 Groenekloof Rd,