Reclaimed Water Grows Vines for Great Wines in South Australia

Reclaimed water produces the right bouquet in SA vines Australia
Monday, 1 October 2007

People may turn up their noses at the thought of using reclaimed water, but a study by the South Australian Research and Development Institute has found that it is not just an alternative source of water for crops, but may be more beneficial than mains water.

Dr Belinda Rawnsley, who led the three-year $350,000 study funded by the Grape and Wine Research Development Corporation, says the results are good news for vignerons and horticulturists looking for sustainable irrigation. "I think this is the way of the future, particularly for the viticulture industry, which is desperate for alternative water supplies," Dr Rawnsley said. Her work has focussed on a vineyard at McLaren Vale, which was established when reclaimed water first became available in the Willunga Basin region through the Willunga Basin Water Company in 1999. "This vineyard has used reclaimed water, from day one, in a trial specifically set up to compare mains and reclaimed water for irrigation of vines," she said.

Earlier and on-going studies by SARDI's Mike McCarthy have shown there is no difference in yield between vines irrigated with reclaimed or mains water. "My study was the first to look at the effect of using reclaimed water, if any, on soil biology," Dr Rawnsley said. "I fully expected to find that there would be more soil borne pathogens or diseases and higher levels of microbial activity. "However, there were actually less pathogens in the soil which is good, and there were indeed higher levels of microbial activity. "This is also a great finding because the higher levels of microbes improve nutrient transfer to the vine."

The Willunga Basin Water Company takes treated water from SA Water's Christies Beach Wastewater Treatment Plant, 10 kilometres north of the Willunga Basin, and pumps it via 70km of pipeline to more than 90 users whose properties cover more than 1500 hectares. The Christies Beach plant treats about 10,000 megalitres of wastewater a year and about a third of that is being used by the WBWC for irrigators. The remaining treated wastewater is pumped out to sea.

The WBWC will eventually have the capacity to take most of the wastewater from the plant.

This study adds to the pressure for improved use of reclaimed water for agricultural and horticultural use in many additional areas of Austraia, rather than wasting it!

In the Northern Territory it points to a definite potential for inceased reuse from a very low base.