The observation by the mayor of Carlsbad, Calif., that stopping population growth is not enough to solve the city's water problem was astute (HCN, 11/21/08). According to the U.S Geological Survey, California is below the national average in per capita use of freshwater of 1,280 gallons per day. This estimate includes all water use, which is driven to a large degree by agriculture, manufacturing, and cooling of power plants. Daily use per capita was reported in the HCN article as ranging from 128 gallons in Los Angeles to 185 in San Diego, which I presume to be residential use only. I recognize that regional water use will vary, but I found those residential statistics shocking compared to my average daily use of 25 gallons.
The need for a massive, expensive, energy-hogging desalinization plant in Southern California to prevent further use of an already over-tapped freshwater supply should be glaring testimony to unsustainable lifestyles in a crowded desert environment. I remain skeptical that substantial improvements in efficiency will reduce profligate use of water (swimming pools, lush landscaping, people cleaning sidewalks with the hose, etc.) until use beyond some reasonable level becomes a true economic burden to the wasteful, not to mention a major social stigma. Let's hope that the looming water and financial crisis bolsters conservation practices (and laws) in Southern California.