If you live in Scottsdale or Gilbert, there is a good chance you use more water than someone in Buckeye or Apache Junction.
Across the Valley, cities, towns and other water providers differ dramatically in the quantity of water their customers use on a daily basis.
Experts say the impact can depend on several factors, from average income to lot size, and that significantly affects a community’s water footprint even when there are water-conservation efforts in place.
Even so, one water-conservation campaign, which released a report on challenges facing the Colorado River, says Scottsdale and other water providers may need to step up their efforts to encourage water conservation and cut down on excess usage.
In Scottsdale, a typical resident uses about 220 gallons of water a day — the highest among major municipalities in metro Phoenix, according to 2009 data, the most recent available from the Arizona Department of Water Resources.
Buckeye residents were the lowest, averaging 60 gallons a day.
So, what does that mean for cities?
The 90 by 20 campaign, which receives its funding from various organizations including Nuestro Rio and Protect the Flows, is asking cities and other water providers in the Colorado River Basin, including those in Arizona, to reduce their water consumption to 90 gallons per person daily by 2020.
Estimates indicate the Colorado River is a vital source of water for more than 35million people and a big source for drought-stricken Arizona. Campaign supporters call the goal “realistic and achievable.”
But water experts say it’s not that simple.
The goal of reaching 90 gallons is based on a community’s gallons per capita per day, commonly known as GPCD. It is an estimate of how much water each resident uses on a daily basis.
Among major Valley cities, Phoenix had a GPCD of 107, compared with 115 in Mesa, 128 in Tempe and 117 in Glendale, according to the state’s data.
The problem is the figures are not always reliable, state officials said.
There is no industry standardization for how to calculate GPCD, “so it isn’t apples to apples,” said Carol Ward-Morris, program manager in demand management and sustainability for the Arizona Municipal Water Users Association.
“GPCD may be a convenient measurement for those who want to simplify complex issues and talk in sound bites, but it does not serve well to compare water use from one community to another,” she said.
In Scottsdale, water usage is heightened by large lot sizes and homes, a large number of pools and large lawns, as well as disparities in billing, and socioeconomic conditions such as a higher median income, water officials said.
Michelle Moreno, spokeswoman for the state Department of Water Resources, agreed there are many variables that impact an area’s water use, such as climate, landscape and population.
“Therefore, it is not realistic to set a one-size-fits-all GPCD target goal for all water providers or cities,” she said.
A community’s service area doesn’t always equal its population, because some water providers serve areas outside their boundaries or do not serve all residents, Moreno said.
Scottsdale, Phoenix and other municipalities also tap water from other sources, including the Salt and Verde rivers and groundwater.
There is little doubt that Arizona has some tough challenges ahead when it comes to maintaining a sustainable water supply. And conservation efforts, although important, “will only get us so far,” said Moreno, who called Arizona a leader among states for water-management practices.
According to the 90 by 20 campaign report, lowering residential water usage across the Colorado River Basin to 90 GPCD would result in savings of more than 1million acre-feet of water annually. An acre-foot is enough to supply about two urban families with water for a year.
But asking residents to turn off their faucets or check for leaks isn’t always simple, and cities and towns say they are going above and beyond to encourage water conservation in their respective communities.
In addition to a tiered water-rate structure, Scottsdale has water-conservation videos, website tips, rebates and free outdoor water evaluations, which is “more than what the 90 by 20 campaign wants,” said Annie DeChance, public-participation and -outreach manager for Scottsdale’s Water Resources Department.
Gilbert, which also ranks among the highest in GPCD among municipalities in the Valley, said it has been encouraging residents to curb excess water use for more than 15 years.
Jeff Lee, Gilbert water-conservation specialist, said that, although the town monitors GPCD to observe trends, “it’s not as simple as that when evaluating a typical person’s water use.”
“The average GPCD number is just that, the average,” Lee said. “In many cases, you will find that people are below the average GPCD.”
Stacey Champion, a spokeswoman for the 90 by 20 campaign in Arizona, recently organized a performance outside Scottsdale City Hall to draw attention to the issue.
“(It) isn’t about playing the blame game and pointing fingers,” she said.
Still, Champion was critical of Scottsdale’s water usage.
“All of these other cities can hit that number: Phoenix, Denver, Tucson — even St. George, Utah, is not anywhere close to Scottsdale,” she said. “What gives them the right to use two or three times more water than (any) other city?”
There are private water providers with higher water usage than Scottsdale. For example, a water-service area encompassing portions of Paradise Valley and Scottsdale has a GPCD of 780. EPCOR Water, which provides water services to that district, said it reaches out to customers regularly to share conservation tips and provide free audits and retrofit kits to its our customers.
Paradise Valley is known for large homes on large lots of at least 1 acre or more.
“Water use is individual to each customer — their lifestyle, their home and the number of people living in the home,” said Rebecca Stenholm, a company spokeswoman.
Stenholm said that roughly 70 percent of residential water use is outside the home, so “lot size, landscaping and water features all play an important role in a customer’s water usage.”
The 90 by 20 campaign acknowledges that “climate, landscape and a host of other factors” influence a community’s water usage and that “it would not be effective to prescribe a single set of solutions across the basin for how to get to 90 GPCD by 2020.”
Phoenix, which is not far off from the 90 by 20 mark, “commends” its residential customers who have helped reduce water use to 107 gallons per person per day — a 27 percent reduction from 15 years earlier, said Ken Kroski, a spokesman for the Phoenix Water Services Department.