Good news for the Southwest and those cities and rural communities whose water supplies depend upon the Colorado River. According to a recent report released by the Pacific Institute, entitled “Municipal Deliveries of Colorado River Basin Water”, while the populations in and around the Colorado River basin have increased by more than 10 million since 1990, the “overall per capita water use declined by an average of at least one percent per year from 1990 to 2008.” This reduction in water use is due primarily to “substantial water-efficiency gains made over the past 20 years by agencies delivering water from the Colorado River basin.” (you can download the full report here.
So while the population grew to almost 35 million people—including citizens in the ever-expanding metropolises of Las Vegas and Phoenix—the water pumped and pulled from the Colorado River has only increased by 600,000 acre-feet, a rate much slower than the population growth, which, according to the study, would have had to increase by almost 200 million acre-feet without increased conservation and efficiency. Instead, demand declined dramatically: in Albuquerque by 38%; in Southern Nevada by 31%; in Phoenix by 30%; and in San Diego County by 29%. Even Southern California agencies—which handle some of the toughest water resource management challenges in the country—were able to reduce demand to 4% less water in 2008 than they had in 1990, “despite delivering water to almost 3.6 million more people.”
And while municipal deliveries (deliveries to the residential, commercial, industrial, and institutional sectors) only comprise about 15% of total Colorado River water use, (agricultural water uses still hovers around 70%) “as the fastest-growing sector, municipal use drives demands for additional water supplies and places pressure on a river system that is over-allocated and facing a supply-demand imbalance, as well as the prospect of long-term declines in runoff due to climate change.” As such, the main goal of “Municipal Deliveries of Colorado River Basin Water” is to highlight the successes of cities that used projections on future water demands as part of their overall water resource management plan of action—success that should “be adopted or emulated by the less efficient water providers.”
So what do you think? How significant is it that, while populations rose, water use fell in some of the most water-strapped regions of the country? Can those successes be duplicated, or were they the result of the low-hanging fruit of fixture replacement and residential irrigation regulations—programs that are already in place in many communities and thus already contributing to demand management? And is the situation in the Southwest too regionally specific to affect and inspire water resource management on a nationwide scale?