Paarl’s Nederburg winery is reducing its reliance on municipal water with a closed-loop irrigation system, saving 45,000 cubic metres annually and improving grape yields and fruit quality. The initiative sets a new benchmark for sustainable water management in South Africa’s wine industry.
Source: Supplied
The winery uses an automated biological wastewater treatment technology, releasing 43 sequenced bacterial strains into cellar effluent. The bacteria break down organic and inorganic matter, including nitrogen and phosphorus, and convert it into safe, reusable water. The treated water, stored in seven farm dams, is used for vineyard irrigation, homestead gardens, and cleaning cellar equipment.
Isabel Teubes, Nederburg’s viticulturist, said: At the same time as we are improving the health of the local river, we are seeing the immensely positive impact of irrigation water quality on the health of our farm soils, their structure and water-holding capacity.
"In a trial conducted with two blocks of Chardonnay on the farm, cultivated in the same way, we saw a 50% increase in yield in the block irrigated with the treated water compared with the control block. And, if anything, fruit quality was in better fruit sugar and acid balance."
She added: "Obviously, we need to observe outcomes over several vintages for discernible patterns to emerge, but after over 20 months, we can already see just how beneficial the bacteria-treated water is for the rhizosphere – the layer of soil surrounding the vine roots and where the vines release nutrients for the soil micro-organisms.
"Enhancing the bio-availability of nutrients is good for vine health and resistance to disease and to climate extremes."
Supplier adoption and water scarcity
Teubes noted that supplier-growers are now adopting the technology, and several Western Cape municipalities and farming enterprises are exploring similar systems.
"Given the mounting spectre of water scarcity in the Western Cape, all of us need to find more water-wise ways of farming," she said.
Soil health and regenerative practices
Heineken Beverages' agricultural specialist Henk van Graan highlighted the broader environmental benefits: "As we begin to appreciate the ecosystems of healthy soils, we are learning in more detail about how their microbial populations provide structural support for all types of plants.
"They help to fix nitrogen, aerate, moisturise and enrich the soil…Aggregate habitat is created to play an important role in filtering, retaining, and draining water."
Van Graan also explained Nederburg’s use of biochar mixed with composted grape waste and recycled water to boost microbial populations, soil structure, and water retention. He noted the carbon sequestration potential of this method: "An important feature of biochar is that it is recognised as carbon negative. It remains in a highly stable form in the soil, indefinitely, storing carbon potentially for hundreds if not thousands of years."
Nederburg has been a WWF Conservation Champion since 2020, recognised for its water stewardship practices, including irrigation efficiency, cellar water reuse, and land rehabilitation.
The farm also played a key role in piloting South Africa’s eco-friendly Integrated Production of Wine protocols nearly 30 years ago, now widely adopted across the country.
