Notes from a Clear Stream

- Jeremy Witts-Hewinson -

So, you thought using eco-diesel was a move closer to saving the planet?

It started in a scrapyard in Oudtshoorn. My wife insists I’m the only person she knows who window shops in an industrial area! I noticed an old Fintail 200D Mercedes Benz standing forlornly in the late winter sun. Having always wanted to include a clattering oil burner in my collection of old Mercs, the saga began.

In a sort of gladiatorial challenge to the scrap merchant, the offer was made on condition that it could be driven off the property. Much slingering, shouting, clattering, and lots and lots of blue smoke later, the engine was running. I nursed her through the scrapyard gates, at which point the column-mounted gear lever plopped unceremoniously to the moth-eaten-carpeted floor! I had a deal which I then wasn’t sure I wanted! The fact that Suzie (that was the name scratched on the key ring) made the 60km drive home without too much drama re-enthused me.

After months of gathering dust and muisvoël droppings under the mesquite tree, a body re-spray and engine reconditioning was carried out.

Aware that fossil fuels are so infra dig, I found an article in a women’s magazine about a person living on her eco-friendly, permacultural, self-contained, energy efficient, recycled, organic, green - and/or all of the above - plot in Noordhoek very interesting.

Choosing to overlook the fact that she sounded like a bit of a modern Marie Antoinette to me, play-playing the modern equivalent of milkmaid-milkmaid in the backyard of the palace, I focused on the point that her little diesel car was fuelled entirely by bio-diesel. This is what’s replacing ever-diminishing fossil fuel resources and saving the planet, we’re told.
What if Suzie, with a few modern modifications, naturally, was able to clatter away happily on planet-saving fuel? A quick response from a company distributing the stuff in the Western Cape led me to a bloke near Gouritz River mouth. Bulk purchasing is the way to go – that is what the aunty in Noordhoek does. I had visions of Suzie towing a small tanker-trailer to purchase supplies.

What stood between me and Suzie saving the planet was the “modification” to her engine. A restoration project that I felt was a little indulgent was going to turn into something really altruistic and progressive! The opportunity to persuade local farmers to come on board loomed. Maybe I could become a regional agent AND help save the planet! I espoused my idea of Suzie being a vehicle for planetary salvation to my environmental guru up the valley and his usual bright and happy face cascaded into a sadly bewildered look of bemusement.

Alas, the profit motive had already hijacked my high-flown ideals. Apparently, virgin rainforests in Borneo are being flattened as you read, to make way for highly profitable palm plantations producing tons of palm oil for highly energy inefficient refineries churning out bio-diesel!

Desperately clinging to my idealism in the face of such brutal truth I stammered, “But what about supporting the emerging Free State farmers in their plan to produce tons and tons of rape seed to be made into environmentally-friendly bio- diesel?” “It’s all genetically modified and causing havoc with indigenous plant species in the area!” You can’t exactly tell the bees where to go a-courting, I suppose…

Of all the plans of mice and men… that plan was surely devised by the mice. What is a non-consumerist eco-warrior to do? Can anyone suggest how I can persuade my 1930’s anthracite consuming Aga to behave more kindly to our dying planet?

Sucking the mountain dry?

Is it possible that by pumping out water for agriculture and use in towns and villages we are drying out the mountain? This is the question that Wietsche Roets, an Aquatic Scientist with Cape Nature in George put to a meeting of the Gouritz Initiative (GI) at Oudtshoorn Proefplaas in December 2006. The GI is a group of landowners and others interested in conservation-friendly and sustainable development in the Gouritz River catchment that extends roughly from Mossel Bay to Plettenberg Bay and from George to Prince Albert.


Wietsche explained that rainfall is far greater on the mountain tops than on the lower slopes or plains of the Karoo. Most of the rain that falls on the mountain seeps down into the Table Mountain sandstone layers and continually tops up the groundwater aquifer that underlies both the mountain and the plains. When the aquifer is full, the water that seeps into the mountain overflows, in hydrological terms “interflows” as small streams on the higher parts of the mountain (see sketch A). Lower down on the mountain, the larger rivers are fed by both interflow and discharge from the aquifer.

When large quantities of ground water are abstracted (or extracted) from the aquifer, a cone of depression forms around the borehole (see sketch B). Depending on the extraction rate and the rainfall, the level of the water table gradually drops, not only around the borehole but may extend throughout the aquifer. The rainfall on the sandstone mountain tops infiltrates, replenishing the ground water in the aquifer, however, according to Wietsche Roets, if the level is not sufficiently topped up because of extraction in the valleys, then water will not “overflow” as interflow in the mountains, and the mountain streams will dry up and perennial streams may become seasonal.

These changes may take many years, so while at first we may see no effect of ground water extraction, in the longer term as the depletion continues, the river flow and water availability will diminish. Once this has happened, the problem is difficult and slow to reverse.

Although the folding and faulting of the sediments make it difficult to predict exactly which stream will dry up when, there can be no doubt that all the underground water in this part of the Karoo and in the Little Karoo is linked with the mountain aquifer. In the Kammanassi, the Vermaaks River has already run dry as a result of water extraction for agriculture.

It is the mountain streams and rivers that give life to many kinds of plants such as the indigenous willows and kiepersols along the Dorps River near Eerstewater, and the diversity of aquatic animals found only in rivers that run through Fynbos vegetation. These include red fin minnows, dragonflies, and frogs of various kinds. Probably less well known is the fact that the larvae of the extraordinary long-tongued horse flies that are essential for pollinating some Fynbos bulb plants such as Afrikaners (Gladiolus species), malvas (Pelargonium species) and orchids, start off life as worm-like larvae filter-feeding on fragments of dead plants in the flowing water of mountain streams.

In making decisions about how we use our water in this beautiful and fertile valley of Prince Albert, we need to remember that the Karoo is in world terms a desert. The water we use does not come from our local rainfall, but from the rainfall on the Swartberg Mountain. The mountain water can sustain the village comfortably, so long as there are not too many people, and so long as our agricultural and industrial development does not use water extravagantly. Water is wasted in many ways – from open and leaking canals through flood irrigation and maintenance of gardens more suited to the European climate

Report by Sue Milton-Dean, Conservation Ecology, University of Stellenbosch and resident of Prince Albert