The line is Goyder's Line, a boundary that marks the limit of sufficient rainfall for crops to grow in South Australia. In 1865 a surveyor named George Goyder set out on a remarkable journey by horseback to trace the point where grassland gave way to sparse bush country. Australia's settlers relied on Goyder's Line to demarcate arable land from land unsuitable for agriculture. Except when they didn't: Renmark, for instance, lay on the wrong side of Goyder's Line, but that did not stop two Canadian brothers named Chaffey from developing an irrigation system in Renmark two decades after the surveyor's warning.
As it turns out, the Chaffeys were three decades ahead of their time. The Australian government inaugurated its first "soldier settlement" scheme after World War I, offering land, water, and farm machinery to veterans. In the decades that followed, orchards and vineyards and wheat fields miraculously sprang up from former scrub desert north of Goyder's Line. Canal after canal was dug to deliver the Murray's water to the new farmland—and later, to sprawling irrigation districts dedicated to the nascent (and highly water-thirsty) rice industry. By the early 1970s, Australia was a major exporter of such crops, its farming lobby had emerged as a formidable political force, and the government was selling off water licenses to any bloke who fancied being his own boss and who wouldn't whinge when the odd drought came along.
Mick Punturiero's grandfather was a Calabrian émigré who bought his first acreage from a retiring World War II veteran, one of thousands more soldiers enticed by the government to develop the basin. The audacity of farming in such an arid area was not readily apparent to Punturiero's grandfather, who had no education other than in how to grow an exquisite grape.
Soon the Murray began to run low, and fields started to salt up. Unfortunately, the prescriptions only helped spread the disease. Leakproof irrigation technology meant that less water returned to the system. Salt interceptors kept crops from being poisoned, but only by pumping out limitless quantities of water. In 1995 the Murray-Darling Basin Commission finally introduced a cap on how much water each state could draw from the river. But the binge didn't end. Farmers who owned water rights but had never used them proceeded to sell their now coveted "sleeper licenses" to others who would. Industrialists were offered tax incentives to create superfarms and introduced vast olive and almond groves to the basin.
Meanwhile, the governments of New South Wales and Queensland routinely flouted the extraction cap and continued to hand out licenses. "The increase in diversions from the Murray River in the late nineties was rather like drinkers in a bar," says Malcolm Turnbull. "The barkeeper says, 'Last orders, gentlemen.' And everyone rushes in to drink as much as they can before they get thrown out. That's what we were doing. Just as it became apparent that resources were overtaxed, there were more claims on it."