Three years ago researchers at Scripps Institution of Oceanography warned Lake Mead has a 50-50 chance of running dry by 2021 and that the reservoir's water level could dip low enough to reduce or stop electricity production as early as 2013. Although this year's run-off probably forestalled this dramatic assertion, utilities around the country have already been forced to reduce or stop electrical production because of water issues. According to a survey done in California's 2009 Water Plan Update, states from Virginia to Nevada and Texas to North Dakota have all curtailed energy development projects because of water quality or quantity concerns.
One reason for this problem is that electricity, as we've chosen to produce it, is pretty wet stuff. Plug an appliance into an outlet and you might as well open a faucet as well. Running an average refrigerator all day uses about as much water as a ten-minute shower (without a low-flow showerhead). According to the U.S. Geological Survey, electric power generation accounts for nearly half of the nation's water usage; it takes on average 21 gallons of water to produce one kilowatt hour of electricity. In the arid West, those numbers add up. A report by Western Resource Advocates notes that "thermoelectric power plants in Arizona, Colorado, New Mexico, Nevada, and Utah consumed an estimated 292 million gallons of water a day in 2005 - approximately equal to the water consumed by Denver, Phoenix, and Albuquerque, combined."
Pretty much every step of energy production requires water, from mining to refining, processing to generation. Some of this water is "consumed" - evaporated as steam. Some of it is returned to watersheds in altered forms - like water heated during coal-fired electrical production and stored in cooling towers or ponds before being released - at higher temperatures - back into rivers. "Produced" water from coal-bed methane extraction releases underground water with high mineral content into watersheds. Deep drilling for seams of underground gas deposits rely on chemicals used in "fracking fluids," which contaminate water sources when they leak.
Other potential fossil fuel energy sources, like oil shale, require so much water during its production cycle that energy companies in Colorado have stealthily acquired rights to develop hundreds of thousands of acre feet of water, even before they've invented a viable technology to turn that rock into oil. An acre foot of water is 325,851 gallons, or enough to cover an acre of flat farmland with water a foot deep.
That's enough water to escalate the state's already intense water disputes into open warfare. "If oil shale energy does become commercially viable, it will be a huge new water drain," says Dan Luecke, a Colorado-based hydrologist and Western water consultant.
Many current energy debates have focused on the massive carbon footprint of fossil fuels like oil, coal and natural gas. But many renewable sources of energy, like corn-based ethanol, have a huge and potentially troubling "water footprint." Corn ethanol made from irrigated crops, for example, can use more than 1,000 times more water than oil refining, according to calculations by Sandia National Laboratory. Industrial concentrated solar arrays can require 800 gallons of water to produce a single megawatt hour. Mike Hightower, a senior researcher at Sandia National Laboratories in New Mexico, cautions that reducing carbon emissions, while crucial, is just one part of the energy equation: Virtually every time you lower the carbon footprint in industrial energy production, he says, "you end up with a bigger water footprint."
As planners look to the future, they have to grapple with some tough trends: the more energy we need, the more water we need. But the availability of fresh water has already reached crisis proportions in many parts of the world, and some experts warn we should be more worried about "peak freshwater" than "peak oil." According to Peter Gleick and Meena Palaniappan, writing in the Proceedings of the National Academy of Sciences, water availability is a growing global problem, especially in regions like the Western U.S. where "almost all major rivers and aquifers and already tapped out." Unlike oil, they write in dry, understated concern, water is absolutely essential for life. "For many uses," they conclude, "it has no substitutes."