The Western Cape receives an annual influx of 48 000 people. At the start of summer 2005 – projected to be both unusually hot and dry – the Cape’s major feeder dams stood at 60% of capacity. Water restrictions inflict a 40% cut in the farmers’ allocation from the Theewaterskloof dam. A 2004 study* reveals the South African wine industry contributes R16,3 billion to the GDP (1,5% of the total) excluding tourism and “supports employment opportunities to the tune of 197 579.”

Such facts do not paint an easily reconcilable picture. There’s no doubt that competition for the dwindling water resources in the Western Cape is hotting up and no agricultural enterprise, let alone the wine industry with its various levels of added value including tourism, can afford to be seen wasting such a precious natural resource.

Legal, economic, environmental and quality issues are indeed awakening the whole industry to the need for more efficient water management.

One of the major changes in water usage arrived with the new Water Act of 1998. Previously anyone could tap off ground water running through his or her property; the new Act decrees “no private water”. Applications for water extraction and storage have to be applied for; neither is easily granted.

Irrigation can be a controversial practice; fanatics claim it negates terroir, forgetting European winegrowers, for whom it is forbidden, employ reverse osmosis and cryoextraction to rectify a natural oversupply from the heavens!

“But vines have been irrigated in the Cape since wine growing started,” advises Prof. Eben Archer, viticultural adviser to the Lusan group. “Until recently, irrigation depended more on regional rainfall than scientific knowledge of the vine’s requirements.”

Now that has all changed. “Irrigation used to be a tool for survival; today it is a tool for quality,” Archer confirms.

Californian winegrower and consultant to several local wineries, Phil Freese, expands on this theme: “Winegrowing is about understanding the effects of water supply to the vine for the physiology of vine growth, fruit formation and grape ripening. We need to use water to grow an appropriately and adequately-sized vine to support the ripening of the fruit, then make the vegetative growth cease while we encourage the vine to ripen that fruit.”

There remains a lingering association of irrigation with quantity. Being able to boast “venerable, dry-land, bush vines” on a label somehow bestows instant quality.

Freese debunks both notions. “I am no more an adamant ‘dry-lander’ than I am one who says that you must have irrigation. The only rule is that one must know the capabilities of the site, the desired outcomes and have a good working knowledge of the tools that one has at hand.” Or as the guidelines set out by the widely followed Integrated Production of Wine system succinctly put it, “Vineyards should be irrigated according to their individual requirements where necessary.”

But the truth is that irrigation systems are being introduced across the length and breadth of the winelands. “In some regions it’s a necessity,” says Chris Malan of specialists, Netafim, “in others, it’s perhaps used once a year to stabilise quality and consistency.”

In the high rainfall Constantia Valley, Klein Constantia’s Adam Mason confirms, “We could farm without irrigation but it would be very foolish in the light of the recent pattern of late rains and warmer winters. With a responsible, scientific approach we can enhance quality and express Constantia fruit in a balanced, positive way.”

Irrigation systems don’t come cheap; Malan says that of total vineyard establishment costs of around R100 000/ha, irrigation can account for R12 000 – R20 000/ha. Nevertheless, he confirms the more expensive and precise drip system outsells the mini-sprinklers in the ratio 80/20. Expensive, but researcher Dr Philip Myburgh highlights drip irrigation’s greater efficiency over overhead sprinklers, “With the former, approximately 90% of water lands on the soil as compared to 60% with the latter system,” he calculates, cautioning that whatever the system, evaporation increases with shallow soils and during daytime irrigation. One only has to look at the overhead jet irrigators pumping madly and wastefully in the midday sun to appreciate that. According to Malan, they are relics associated with old vineyards but one wonders why they are still permitted.

How much more precise and efficient can irrigation systems become Chris Malan takes a holistic view: “By accommodating everyone and involving all the disciplines connected with developing a vineyard, a good irrigation plan is possible.” A similar process of integral planning has been one reason for Australia’s success.

There have also been major advances in the science of irrigation over the past 10-15 years. The introduction of soil moisture probes, partial rootzone dry and deficit irrigation have all helped to improve grape quality while cutting down on water usage – Philip Myburgh estimates savings of 20% but admits that “science works slowly; it can take 20 years to observe full results.”

Further water saving strategies: Myburgh suggests there is still much to be done on when and how much to irrigate with possibly a different solution for each variety. The bottom line, he emphasises, is that “Income counts most. You have to look at yield in relation to water efficiency.” In as much as low yields don’t always equate to better wines, so they don’t necessarily equate to sustainable wine growing.

Water is, of course, as important in the cellar as in the vineyard. “The ISO 14000 environmental management system forces you to really focus on reducing water consumption during the winemaking process; ours was significant,” says Vrede en Lust’s Dana Buys.

The system is primarily concerned with “what any organisation does to minimise harmful effects on the environment caused by its activities – either by pollution, or by depleting natural resources,” as the ISO website puts it. The process is ongoing rather than finite. The sort of water-saving practices implemented at Vrede en Lust include high pressure for washing with all hose pipes fitted with water savers and regular monitoring of effluent water to ensure various parameters are within legal limits.

Innovation is the catchword for IPW. “The search for cleaner, more economic cellar practices, especially with regard to water usage is ongoing,” stresses Manager, Andries Tromp.

Will the burgeoning wine industry be able to save water and maintain its important contribution to the GDP Perhaps that bumper sticker “Save water, Drink Wine” unwittingly spells it out: if we can save water, then we can look forward to drinking the Cape’s ever better wines for many years to come.

`The Macroeconomic Impact of the Wine Industry on the Western Cape’s Economy in 2003′ Conningarth Economists. The study also reports on the wine industry’s contribution to GDP per unit capital invested and questions whether it is fair and reasonable compared to other industries. It “… showed that its GDP/capital ratio of 0,46 is only slightly lower than the national average (0,47). Even though this is not a measure of the profitability of the industry, it does signify that its capital `productivity’ is in line with the average for the national economy.”

Turning Water into Wine, an article covering the Australian wine industry’s competitive relationship with other agricultural enterprises and illustrating comparative figures for water usage versus net returns, can be found in the July-August 2004 Australian & New Zealand Wine Industry Journal. Regrettably such a complete analysis is not available here.

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