WaterSense Label Identifies Smart Irrigation Technologies

By Stephanie Tanner and Jill Hoyenga

Each time Americans use a WaterSense labeled product in their homes — whether it be a toilet, faucet, or showerhead — they use about 20 percent less water than if they had used a standard model. Since 2006, the U.S. Environmental Protection Agency (EPA) has worked to enhance the market for water-efficient products and services by setting voluntary criteria for efficiency and performance that must be met in order to earn the WaterSense label.

In the area of outdoor water use, however, the picture is more complex. The water that Americans use outdoors, primarily to maintain lawns and landscapes for homes, office parks, malls and athletic fields throughout the United States, adds up to billions of gallons each day — more than 7 billion gallons in residential use alone. Furthermore, up to half of the water used in landscape irrigation is wasted due to evaporation, wind or runoff often caused by improper irrigation system design, installation, maintenance or scheduling.

Improving the efficiency of outdoor water use is not as straightforward as installing a product that will automatically save water. The amount of water used is related to how people irrigate, how well irrigation systems are designed and installed, whether they are regularly maintained, and whether the irrigation schedule is adjusted for rain and seasonal weather fluctuations.

For this reason, WaterSense strives to improve landscape irrigation efficiency through an approach that focuses on programs, partners, and products. Since 2006, WaterSense has labeled certification programs for irrigation professionals that include a strong water-efficiency component. Irrigation professionals certified through these programs can become WaterSense partners, demonstrating their commitment to practicing irrigation design, auditing, installation and maintenance in a water-efficient manner. Water-savvy professionals and water-efficient education is critical, but we also need sophisticated irrigation technologies to continue to improve efficiency in landscape irrigation. In November 2009, EPA issued a draft specification to label weather-based irrigation controllers, adding products to the approach.

Watering when needed

As most irrigation professionals are aware, weather-based irrigation controllers are one type of Smart technology designed to increase the efficiency of residential and commercial irrigation systems. The controller adjusts the irrigation schedule based on landscape attributes and real-time weather data, applying water only when the landscape needs it. A weather-based controller uses information from on-site sensors or local weather stations to determine if the sprinklers need to kick on, and for how long.

Potential water savings from weather-based irrigation controllers are significant. Manually programmed clock timers, currently the most common method used to schedule irrigation, run like clockwork no matter what the conditions. Few homeowners know when or how often to irrigate when using these systems. Many others simply forget to fine-tune this modern-day convenience to the changing weather or seasons, resulting in systems that run in the rain or irrigate on a summertime schedule in December. Weather-based irrigation controllers make these schedule adjustments automatically by tailoring the amount, frequency and timing of irrigation to current weather and landscape conditions.

Field tests on weather-based irrigation systems in residential landscapes have demonstrated water use reductions in the 7 percent to 30 percent range. However, water savings depend on the geographic location of the landscape, the type of controller used, and the irrigation behavior of the user prior to installation.

There are an estimated 13.5 million irrigation systems currently installed in residential landscapes throughout the United States, and an additional 308,000 new systems are installed each year as a part of new home construction. Of the 13.5 million installed units, industry estimates show that less than 10 percent use weather-based controllers to schedule irrigation. In the final calculations, the EPA estimates that if every home with an automatic irrigation system installed and properly operated a WaterSense labeled irrigation controller, the nation could save about 150 billion gallons of water annually from no longer overwatering lawns and landscapes as well as more than $400 million in homeowners’ utility costs.

The specification development process

When WaterSense began working with the irrigation industry to determine how to measure the performance and water-savings potential of these technologies, it looked to the work of the Smart Water Application Technologies (SWAT) initiative. Formed in 2002, SWAT is a voluntary partnership among water purveyors, irrigation equipment manufacturers, and irrigation practitioners created to promote and test irrigation technologies that adjust irrigation schedules based on plant needs. To identify high-performing products, SWAT developed an initial version of a testing protocol in 2003. SWAT has continued to refine the protocol, based on input from myriad stakeholders, since initiating the protocol.

Although EPA used the SWAT protocol as the basis for measuring performance in its draft WaterSense weather-based irrigation controller specification, every product that earns the WaterSense label must be independently tested and certified to meet EPA’s criteria for both water efficiency and performance. To achieve this certification, manufacturers of weather-based controllers will have their products tested by an
EPA-licensed certifying body (to learn more about the process, visit www.epa.gov/watersense/partners/certification.html).

After EPA issues the final specification, manufacturers of weather-based irrigation controllers may submit products for testing and will be authorized to use the WaterSense label with certified products. In addition, manufacturers and distributors of WaterSense-labeled irrigation controllers will be invited to become WaterSense partners and commit to spreading the word to consumers about how to use these products correctly to achieve water savings.


Brian Vinchesi, president of Irrigation Consulting, Inc., Pepperell, Mass., and the 2009 WaterSense Irrigation Partner of the Year, has chaired the SWAT initiative since it began in 2002. “This is the first outdoor product that’s going to be eligible for the WaterSense label, so we’re very excited about it — I’m very excited about it,” said Vinchesi.

Vinchesi explained that the SWAT testing protocol employs a virtual model to test a controller in six different zones using calculations for different plant materials, root zones, and slopes — the full gamut of possibilities in the real environment. The test provides two measures of performance — irrigation adequacy and irrigation excess. Irrigation adequacy measures how well the landscape’s water needs are met, while excess is a measure of water applied above and beyond the landscape’s needs. Thus, the test shows that an efficient controller can deliver enough water to keep plants healthy without overwatering.

WaterSense partners bring expertise

Whether installed by a professional or by a homeowner, weather-based irrigation controllers maximize water savings when they’re installed on irrigation systems that have been designed, installed, and maintained properly. In other words, it’s important to view the system holistically — using water-efficient components, ensuring efficient distribution uniformity, maintaining the system, and repairing leaks.

That’s where the partnership aspect comes in. WaterSense is partnering with irrigation professionals who have completed a WaterSense-labeled certification program that includes a strong water-efficiency component. These WaterSense irrigation partners know how to design, install, maintain or audit irrigation systems for optimal efficiency. They are the key to making sure the system performs well overall.

The map below shows the number of WaterSense irrigation partners by state.

Benefits of WaterSense partnership

Irrigation professionals looking to differentiate themselves in today’s market will gain many benefits by becoming certified through a WaterSense-labeled program and becoming a WaterSense irrigation partner. Green building is burgeoning and there is an increasing focus on maintaining a beautiful landscape in ways that do not impact the environment.

Numerous voluntary green building programs provide points for hiring a WaterSense irrigation partner. For example, the U.S. Green Building Council’s LEED for Homes rating system provides points for minimizing outdoor demand for water by installing an irrigation system designed by a WaterSense partner. Likewise, builders meeting the National Association of Home Builders’ National Green Building Standard receive three points in the water-efficiency section for contracting with WaterSense irrigation partners.

For a home to meet the WaterSense specification for single-family new homes, if the home has an irrigation system, it must be designed or installed, and audited, by a WaterSense irrigation partner. Executive Order 13423, which requires federal agencies to reduce the environmental impacts of their operations, offers implementing guidance to federal facilities which instructs that, where available, they hire WaterSense partners for landscape irrigation. These requirements — along with national recognition by EPA — will continue to drive demand for the services of WaterSense irrigation partners.

Important considerations

To realize the potential water savings of weather-based irrigation controllers, it is important to heed a few key guidelines. First, the initial programming of the weather-based controller is essential for it to operate correctly, and during the first six months to one year of operation, it should be checked and recalibrated if necessary.

“It takes a little longer to set up and get adjusted and to tweak because it’s a more sophisticated controller and a Smarter controller,” said Vinchesi. “[Homeowners] can’t just slap one on the wall and expect it to work. A controller needs a professional to install it, and it needs a little bit of adjusting in its first months in order for it to work to its maximum efficiency.”

Secondly, the use of weather-based controllers should be targeted toward landscapes that are currently overwatered. Often controllers are set to apply amounts of water that meet or exceed 100 percent of plant water needs based on agricultural requirements for optimal yield, the evapotranspiration rate for each of the various landscape plants (ETc). Plants may not require this amount of water to remain healthy, and in some areas of the country where water conservation is promoted, landscapes may be adapted to receiving less water than this. If a weather-based controller installed on a conservation-adapted site is set to apply 100 percent of ETc, it could end up applying more water than the landscape previously received. To install a weather-based controller in this situation, it is preferable to program it to water at a percentage of ETc. Irrigation professionals with experience in these technologies will be able to address this issue in the field.

Finally, it is critical to remember that the weather-based irrigation controller is part of the overall irrigation system and can only perform as intended if the system is properly designed, installed, audited and maintained over time.

The market angle

Promoting WaterSense-labeled irrigation controllers to your customers will offer myriad benefits to your business. Green is the color of money, healthy landscapes, and environmental stewardship. Many customers want to be “green,” but they don’t want to sacrifice quality. Products that earn the WaterSense label are efficient products that are performance tested.

Selling WaterSense-labeled controllers will demonstrate to customers that your business cares about keeping their landscape in top form, and also about reducing the amount of water used in the process. Weather-based controllers have the potential to save customers water — as well as money on water utility bills.

In addition, the weather-based controllers that will earn the WaterSense label are more sophisticated than a standard controller and will benefit from the knowledge of experienced irrigation professionals to install, adjust and maintain them. Forward-thinking landscape and irrigation designers increasingly recognize that having a sustainable business model involves knowing the direction that the industry is heading: those who capitalize on it are positioned to benefit.

If homeowners and property owners use properly programmed, WaterSense-labeled weather-based controllers, Vinchesi said, they will save water, as well as receive tangible environmental benefits. “A Smart controller does a much better job at providing the required amount of water to the plant — when it needs it — so it will have better root zone moisture management and that sort of thing,” he added. “Also it’s the green and sustainable thing to do, and it’s hard to put a dollar amount on that.”

Even so, some weather-based irrigation controllers may be more expensive than a standard clock timer controller. However, a number of water utilities offer rebates for weather-based irrigation controllers, which can help defray their costs and provide a motivator for residents and businesses to install them. Landscape or irrigation contractors who become knowledgeable about rebate options in their area can help connect customers with utilities and earn benefits that affect both parties’ bottom line.

Stephanie Tanner is product development coordinator for the U.S. Environmental Protection Agency’s WaterSense program. She is responsible for all technical aspects of the development of labeled products including setting efficiency and performance criteria, as well as managing the certification process. Prior to EPA she managed a water-efficiency program for federal facilities and wrote a number of guides to water efficiency for federal facilities.

Jill Hoyenga worked for 15 years in the landscape industry including five years as an irrigation specialist before being hired as a water management specialist for the Eugene Water & Electric Board. She currently supervises a work group responsible for demand management and cross connection control at her utility. In her 14 years in the water conservation field, she has developed and implemented several award winning programs. She is the past-chair of the Pacific Northwest Section of the American Water Works Association Water Conservation Committee and was the initial-chair of the Irrigation Association Smart Water Application Technology Promotion Committee. She is currently co-chair of the Alliance for Water Efficiency WaterSense and Water-Efficient Products Committee.

To learn more about the draft WaterSense specification for weather-based irrigation controllers, to consult with a WaterSense partner about your next project, or to learn how to become a partner, visit www.epa.gov/watersense

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