Thirty years after Marc Reisner penned Cadillac Desert: The American West and Its Disappearing Water his prophesy is being fulfilled. As the chalky rings which mark previous higher water levels around Colorado River reservoirs grow ever wider, Grist reports that major disputes are now afoot over the remaining water supply.
Modern economists have long told us not to worry about resource scarcity. Higher prices will bring on new supplies whenever resource supplies decline. And, if a resource truly is becoming unobtainable, then we’ll always find a substitute.
When I hear this, I often counter: “There is certainly some truth to what you are saying. But, please tell me what the substitute for potable water will be.” The response is usually to change the subject—for the obvious reason that there is no substitute.
A Scientific American article in 2012 put world freshwater usage at more than 9 trillion cubic meters for per year. Per capita, Americans, not surprisingly, consumed more than twice the world average. Certainly, there is much room for water conservation in America and in the American West.
But what does conservation mean when 70 percent of the world’s fresh water is used for agriculture? Of course, it means that conservation is going to affect food production. At first, it might mean simply making irrigation systems more efficient through, say, drip irrigation.
But once conservation has achieved all that it can achieve, what will we do? It is important to remember that what is normally measured when it comes to water consumption is “freshwater” consumption. The water optimists will point to the vast brackish aquifers still available to us humans, not to mention the almost limitless supply in the oceans. The fact that the U.S. Geological Survey was asked by Congress to survey brackish water availability in the United States is an indicator of how serious the situation has become.
However, the fact that something is available is not the same as it being affordable. The key ingredient to making salty water fresh is energy, lots of it. Desalination technology is now widely available. Israel, for example, now gets 60 percent of its water from desalination plants, a build-out that came after a long drought that taxed other water sources. With a renewed drought drying up the remaining sources, Israel plans to build two more plants to supplement its water needs. The Israelis have managed to keep water bills down to levels comparable to major cities in the United States, where water is by world standards relatively cheap.
This technology will work only for those who have the financial resources and technical expertise to build and run such plants, have the necessary water infrastructure to distribute the desalinated water, and who live near large bodies of saltwater. For those far inland such arrangements may not be practical unless vast brackish aquifers are available at a reasonable depth. The deeper the water, the more energy it takes to lift it and therefore the costlier it is too lift.
But affordable desalination is all premised on cheap energy. And, cheap energy may not be a given far into the future in a world where 80 percent of society’s energy comes from finite fossil fuels. (One needs also to consider that the burning of fossil fuels to run a desalination plant contributes to the very climate change that is making droughts longer and more devastating—creating the need for more such plants.)
Most people believe (wrongly) that renewable energy will soon come to rescue even though the combination of wind, solar, geothermal, wave, tidal and ocean energy accounted for only 1.5 percent of total world energy consumption as of 2015 according to the International Energy Agency. And, hydroelectric generation which depends on the very waters now in short supply in the American southwest makes up just 2.5 percent of total worldwide consumption.
People keep moving to the southwestern United States where a long drought continues to aggravate water problems. One wonders whether this area of the country would be so attractive if water rates there represented the true cost not only of supplying water, but also of replacing it as the current sources of water run down.
Danes on average pay the most of any country for water. They do so not because Denmark is poor in water resources, but because Danish water policy insists that users pay the full cost of the water system. In the United States, vast subsidies make water cheap for agriculture and encourage waste. (See here and here.)
It turns out that there is no substitute for potable water—despite what economic theory may wish to assert. To get enough of it in many locales will be increasingly expensive as we turn to ever more exotic means to extract water while both population grows and climate-enhanced droughts diminish replenishment of existing sources.
Photo: Farmer Drinking Water from Deep Pump, Bangladesh (2017). By Vespertunes. Via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Drinking_Water.jpeg