Price of harvesting rain in South Africa

The price of water is rising sharply in the ritzy yet dangerous countryside around East London. Even the rich, old, white landowners are going into rainwater harvesting to protect themselves from municipal price increases.

Land surveyor Neil Henderson is doing it at his Nahoon Mouth home – collecting water off his roof, storing it in tanks and he believes it is the way to go.

He recently had eight 5 000 liter tanks installed. He says in 2007 each tank would have cost 2785 Rand (about $276 US), a 5% a year increase from 2004, and at today’s R3369 would have amounted to 10% a year escalation.

“Municipal water [at the premium price] increased from R8.06/kl in 2004 to R11.89 in 2009 at 8.1% a year, 10% to today’s R17.40 and next month it goes up another 15.3%,” he says.

“So, if a 5000 liter tank held R40 worth of municipal water in 2004, 50 tanks full would have covered the initial R2000 outlay.”

He continues: “In other words 50mm of rain would have to fall on 100m² of roof to fill a 5000l tank. East London’s annual rainfall is 850mm so you could accumulate about 17 full tanks a year. It should then take 2.94 years to get 50 tanks of water. So the tanks would have been paid off in about three years. At next months increased water tariff of R22.69/kl you could now be getting a return of R22.69 x 5kl x 17 tankfuls & x003D; R1928 a year from one tank.”

He continues: “The website www.jojotanks.co.za says: ‘Rand Water is predicting that demand in South Africa will outstrip supply by 2025. It also believes that Gauteng is potentially facing a water shortage as early as this year. In Cape Town there could be a shortage by 2016’.” And that of course will mean higher prices still.

Neil goes on: “Any investment [his is around R40000] with the guaranteed potential future return in excess of 15% per annum, seems attractive. Of course there are many variables to the calculations like maintenance, power costs for pumps, filtration, lifespan of tank etc.

But the fundamentals seem compelling.

“A neighbour, a few houses from me, probably has 80kl storage capacity and I see two new 10000l tanks lying in his yard. The plumber who installed my system is building his new home off the grid with two 300l solar systems and 20000l storage and I hear of many similar stories, so I’m not alone.”

Neil’s is a sophisticated plan incorporating things like a “first flush system” which is a PVC trap so that the first bit of rainwater off the roof does not enter the tanks, but instead washes dirt, leaves and bird poo, for example, away before clean water is collected.

There is also a purifier at the kitchen tap to make drinkable water, and an irrigation system fitted to the washing machine that uses eco soft washing powder. Its waste water will keep the garden irrigated.

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