Smythe seemed to have won the day in LA, and the irrigation of the Colorado Basin, culminating in the construction of the monumental Hoover Dam in the 1930s, brought agriculture and abundance to the desert.
In the first episode of this ambitious, if confusingly titled programme, Simon Schama, one of Britain's most eminent and certainly most visible historians, examined the forces which built America and which will shape its future, at a time when the most powerful nation in the world is preparing to elect its next leader.
Significantly, while the US is distracted by financial turmoil and the war on terror, it may be ignoring its greatest challenge - the rapid evaporation of its most precious resource - water.
Schama explained that the pioneering spirit of America had been powered by the massive optimism of its leaders, notably 19th century president Andrew Jackson.
But farming on an industrial scale in the Mid-West quickly turned Oklahoma into a dust bowl, as windstorms blew away the topsoil in the 1930s. Meanwhile, paradoxically, the waters of the Colorado River made what was formerly desert into America's bread basket, and made cities like Las Vegas, feasible.
Yet - and here is the future part - as oil diminishes, corn is being grown to manufacture bio-fuels. Yet to grow corn you need water and the water, said Schama, was disappearing fast. Even more ominously, the cities of the West have been threatening to divert water to use on water features and golf courses - threatening the very agriculture which brings food to their supermarkets.
Belatedly, America is waking up to the fact that the resources which have fuelled the world's greatest economy are fragile and finite and, like its supply of credit, could dry up overnight. Could we be entering a new world of food shortages?
Thirty years ago, President Jimmy Carter, who presided at a time of fuel shortages, warned that America was going to have to learn how to conserve its resources. America was not ready to listen and he was trounced by Ronald Reagan whose philosophy was similar to that of Jackson's - that the land would always provide. The nine-year drought that has afflicted the western United States would suggest that American resourcefulness will be tested as much as its resources in the coming decade. Significantly, said Schama, both candidates in the coming election were preaching caution and conservation.
If we learned that water was short, the American landscape, filmed beautifully, seemed endless - and the gnarled survivors of the Great Depression spoke with pain and wisdom of their trials.
So will it all come back to haunt us? Eight years of George W Bush's obsession with an unwinnable war on terror and denial of the fact of global warming, has taken America's eye off the ball. It remains to be seen whether Barack Obama (or the other guy) will have the strength to rein in the rampant consumerism of their country.
His foe, in a conference in Los Angeles whose stakes were literally the future of the American landscape, was John Wesley Powell, a man whose hazardous journey along the length of the Colorado river had taught him that over-settling and over-use of the country's water resources could spell disaster.