The U.S. Department of the Interior reports that overall water consumption in the United States has declined in the past 25 years, even though the population has increased 30% and use by individual American households has increased. The statistics were compiled by the U.S. Geological Survey.
What’s the secret? The 25-year patterns of water consumption revealed in the DOI report provide tantalizing clues about the ability of the U.S. to sustain its legendarily consumer-centric lifestyle while stabilizing and ultimately decreasing its contribution to carbon emissions and other greenhouse gasses.
Water Consumption in the U.S.
Even though U.S energy use has skyrocketed in the past 25 years, according to waterandwastewaternews.com the DOI ‘s 5-year reports show that water use peaked during 1975 and 1980, and usage in 2005 was actually less than in 2000. We can’t thank household or commercial conservation for that. Public water supplies have steadily continued to increase their output since the 1950′s. The real champs in water conservation have been the one-two punch of more efficient irrigation systems and the shift away from once-through cooling technology in electricity generating plants.
Water Consumption Breakdown
Even with new water-conserving technologies, electricity generation still accounts for almost 50% of U.S. water use. Irrigation sucks up another 31%, and though overall irrigation use declined the DOI found that irrigation actually increased in some states. Only 11% of U.S. water consumption goes to public water supplies, and another 9% goes to miscellaneous users that don’t draw from public supplies, including aquaculture.
Clues for the Future
The main takeaway from DOI’s report is: yes, we can. Stabilizing, let alone decreasing water consumption in the face of rapid population growth with a high-maintenance lifestyle is quite an achievement. Though it may be an apples-to-oranges comparison, the report also suggests that the biggest factor in a similar reversal of greenhouse gas emissions in the U.S. will be the adoption of new technology for energy generation, and that reining in emissions by the public will be much more challenging.
Desalination and Alternative Energy
One water consumption and greenhouse gas emission variable on the horizon is the increased use of desalination facilities to address regional water needs. Although advances in technology are cutting down the energy needed by conventional desalination plants, in the future desalination may account for a significant chunk of the U.S. water supply (including the U.S. Navy and other military users) and consequently its energy consumption, too. Adopting wave power and other sustainable energy sources for desalination plants will be the key to developing the ocean as an important new water source without delivering more greenhouse gasses into the atmosphere.
Image: woodleywonderworks on flickr.com.
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.