Can water efficient technology save us from ourselves?
9 Sep, 2008 By: Doug BennettTechnology has brought us more than 60-in. televisions. It's also produced some remarkable innovations in water efficiency.
Today's plumbing fixtures and home appliances are more efficient and effective than ever before. The newest toilets flush effectively with 60% less water than their 1980's counterparts. High efficiency washing machines use less than half the water of traditional toploaders. Irrigation controllers and sensing technology can predict when our plants need water, while drip irrigation and high-performing sprinkler nozzles allow us to place that water more accurately than ever before.
With all that technology, today's homes ought to use a fraction of the water of an older home, right? Not necessarily, according to preliminary results from a nationwide, EPA-funded study that's looking at water use characteristics of new homes. One component of the nine-city study compared water consumption of 9,000 homes built prior to 2001 and 9,000 built after 2001. In seven of the nine cities, new homes were found to be using more water than their older counterparts - as much as 40% more.
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How can that be?
While indoor water technology may have taken two strides forward, the study indicates we may be walking on a treadmill. For example, although federal law limits a showerhead to 2.5 gallons per minute, there is technically no limit on how many nozzles may be plumbed into single stall. In more and more homes, the shower is no longer a simple hygiene appliance. Instead, it is a spa-like escape, with fixtures that may command more than 10 gallons per minute. In addition to the flow, new amenities encourage lingering as users call up their favorite music or even work on their skin tone under integrated tanning lamps.
While most Americans are still mostly business under their single showerhead, we typically have more bathrooms than our parents did. In the 1950's a single bathroom was the norm. By the 1960's two bathrooms became the norm for middle America. Today, three to five bathrooms are common in new homes.
Granted, more bathrooms don't translate to more flushes, but it does assure more water use since about 20% of toilets have a leaking flapper. Other modern conveniences, such as water filtration systems and softeners, serve to further consume water conserved elsewhere in the home.
As quickly as efficiency innovation can establish itself, consumptive designs and behaviors may push it back. As a result, the data indicates winter water demand of new and old homes is nearly identical.
The good news is that higher occupancy of the new homes equates to a 12% reduction on a per person basis.
Occupants, however, have little bearing on outdoor water use. The study found a strong upward trend in seasonal
water use, with newer homes averaging 13% more water during the growing season than the older homes, despite a 6% average reduction in lot sizes. While additional inquiry is needed, preliminary data suggest that higher rates of landscape irrigation are responsible for the trend.
Surprisingly, the largest increases in growing season water use were seen in cities with high precipitation: Eugene, OR, and Jacksonville, FL. These two cities saw increases in growing season demand of 62% and 70%, respectively. In both cases, growth in use coincides with increased prevalence of automated irrigation systems.
Only two of the nine cities showed reductions in seasonal water use: Phoenix and Las Vegas. In these two cities, almost every new home has an automated irrigation system.
Water isn't the only resource affected by higher demand. Peak summer water use is the principal driver behind infrastructure sizing. Water utilities must construct and operate facilities that meet and exceed the peak summer demand; the one single day when the community demands more water than any other. In essence, the system is overbuilt for the other 364 days of the year.
The treatment and movement of water is one of the most power intensive operations in any municipality. In the Las Vegas region, water agencies use more than 1,000 kwh per year to meet the water needs of a single home. Despite the agencies' efforts to accelerate use of green power, each home's water use broadens their carbon footprint by almost one-half metric ton annually.
That's water production and delivery only and doesn't include any water-related energy used within the home or to treat the wastewater produced by each home.
We may be doing the right things, but are we doing them the right way?
We can't blame automated landscape irrigation for increased use anymore than we could blame an automaker for a speeding ticket.
It is the combination of how we design and manage our landscapes that ultimately decides outdoor water use. It is clear, however, that we need to do it well, do it swiftly, and do it collaboratively.
Water agencies cannot do the job alone, though some still try. While regulatory approaches can be highly effective, even those are most successfully implemented with the support of stakeholders. The landscape industry is one of the most critical water efficiency partners in any community.
For the private sector, water efficiency must be profitable. For the end user, it must sustain or improve quality of life. Anything less will have very low appeal at a time when widespread adoption is critical.
In the Las Vegas region, government and industry are pursuing efficiency through partnership. The Southern Nevada Water Authority's (SNWA) Water Smart Home program, the nation's largest program for water efficiency in new homes, assures use of efficient fixtures, appliances, landscape design and irrigation techniques. More than 7,000 homes have been built to the voluntary specifications.
A common misconception is that the interests of the landscape industry and water conservation are at odds. The SNWA has injected over $100 million in incentive money into the landscape industry since 2000 and has budgeted over $45 million for the current year.
More than 30,000 properties have participated in a program to retrofit existing high water use landscapes to water efficient landscaping. These incentives have stimulated more than $300 million in new business for the landscape, irrigation and nursery industries in the region.
Funding for the programs comes primarily from new connection fees, thus new customers pay for programs that help make their water available.
SNWA's Water Smart Contractor program provides training and marketing for about 80 participating landscape companies.
These companies are featured on the agency website and are allowed to use the program logo in their advertising. In return, they agree to abide by water efficiency principles on all projects.
These programs have been valuable tactics in a multi-faceted effort that has reduced Southern Nevada's per capita water use by 20% in the last five years without compromising quality of life.
Still, these are but a few steps on a much longer path.
In virtually every city, growing water demand will eventually challenge the infrastructure, the limits of the water resource, or both. Communities with seemingly ample supply may find themselves in crisis as a result of drought or a court decision. It is not so much "if" as "when."
We cannot continue on a course when we already know the path will be blocked ahead. Working together, government and industry have the ability to navigate a more sustainable course that appeals to the consumer.
Whenever I ponder the course we're taking, I ask myself whether future generations will cheer, or jeer, the decisions we've made. As it stands today, I'm envisioning a smattering of polite applause. We can do much better.
Bennett was one of four presenters at the most recent Intelligent Use of Water Summit, this one held at Arizona State University, Tempe, AZ. Look for expanded coverage of the Summit in Landscape Management magazine.
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