by Martin Field
My daughter, who studies these sorts of things, says we shouldn’t think in terms of drought in Australia. She argues that Australians will eventually have to accept that we live in the driest populated continent on the planet and that the 100 year ‘drought’ we’re experiencing at the moment is simply a variation on what is in fact a permanently arid environment.
I tend to agree. In Melbourne and in other Australian cities we’re already living with water restrictions. Yet, as our population and water usage increases, we go on wasting water as if there is an infinite supply. The federal government however, seems to be in a state of denial about global warming, despite recent headlines such as, Climate change to hit Australian wine industry and Business chamber warns grape growers are wasting water. You don’t have to be a Homer Simpson to envisage what effect enduring global warming will have on an already drying out countryside.
Some figures: according to the Australian Bureau of Statistics, over 7,000 vineyards in Australia irrigate their vines, some 84% of total vineyards. The area of vineyards irrigated is approximately 150,000 hectares. At an average usage of 3.76 ML/ha (megalitres per hectare), this equates to approximately 564 gigalitres of water used in 2005. This is more fresh water than the amount of seawater it takes to fill Sydney Harbour. (Source 1329.0 – Australian Wine and Grape Industry, 2005)
Sure, rice (12.1 ML/ha) and cotton (6.7 ML/ha) use more irrigation water than grape growers but that is not an excuse for overuse. A trend towards dryland viticulture is looking more and more imminent, inevitable and perhaps, desirable.
But, I hear you say, mightn’t that lead to a dramatic cut in wine production? My reply is that when we have a national water shortage and an ongoing wine glut, crop reduction through better managed irrigation would be no bad thing.