Riverina is a massive district in the dry scrub of western New South Wales that relies entirely on irrigation for the production of wine. This is an area much like the Central Valley of California that contains large scale plantings that the big firms use to supply the major international fighting varietal brands. Indeed, Riverina accounts for 15% of the entire nation's output of Shiraz as well as a significant chunk of Chardonnay and Semillon. (Wine/Appellations)