The latest generation of products is more affordable and offers benefits beyond water conservation.
It turns out it’s not true that “everybody talks about the weather but nobody does anything about it,” as Mark Twain is reported to have said. Weather stations have been used for at least 20 years as a tool for efficient water use in irrigation, but their cost and complexity have limited their use. However, as irrigation products evolve and conservation efforts take on greater urgency, it’s important for water conservation professionals to understand the available options in weather-based irrigation controllers, as well as the changing regulatory environment related to these products.
Weather stations, explains Jeremy Schalk, marketing group manager at Rain Bird, “range from simple rain measurement devices to stations that have a full complement of sensors” measuring such conditions as solar radiation, air temperature, relative humidity, wind speed and direction, and rainfall. Weather stations with the full range of sensors, says Schalk, “are typically used to calculate evapotranspiration—or ET—the water loss due to evaporation and plant usage.” That information—which is transmitted from the weather station to the user by means of phone, radio, or wireless signal—”is then used to apply the correct amount of irrigation given the daily weather conditions.”
The water conservation and other environmental benefits of such systems are well-documented. According to the EPA, as much as 50% of the water used for landscaping is lost due to overwatering, evaporation, or bad irrigation system design or maintenance. Studies conducted by the Municipal Water District of Orange County, CA (MWDOC), found that using ET-based controllers saved 42 gallons per day per controller for a single-family residence and 525 gallons per day per commercial controller. In addition, says Joe Berg, the MWDOC’s manager of water-use efficiency programs, the use of such controllers results in runoff reduction of 50%, with commensurate reduction in pollution.
Despite their efficacy, weather-based central control irrigation systems historically have made financial sense for only a limited number of users, because they required the purchase of a weather station, a computer control system, and software. The substantial capital investment required for these systems—and the costs of maintaining them—made them feasible only for such customers as municipalities, school districts, and golf courses. In fact, the capacity that these types of systems offer, such as frequent reprogramming of schedules to accommodate people and traffic flow and the ability to control multiple sites, mean that they continue to be an excellent option for institutional users with a particular need for those features.
Ellen Beighley, president of Irrigation Management Systems in Portland, OR, uses a central controller to manage the landscape irrigation needs of her clients, which include Nike, Willamette National Cemetery, and homeowners’ associations, because she feels that as a specialist, she can provide the best service to her clients. Beighley prefers using onsite weather stations, because she believes they provide more accurate data than subscription services that provide data from a weather station that may be some distance from—or in a different climate zone than—the landscape being irrigated. (She emphasizes the importance of regular maintenance of the weather station in obtaining accurate data.) Beighley also strongly recommends having a qualified irrigation technician set up an ET-based system, because the property owner won’t get good results if the irrigation system is set up based on poor data or faulty assumptions.
The upfront and maintenance costs and increased complexity of weather stations have meant that central controllers were not affordable for the general consumer. But ET-based irrigation control is now available to smaller commercial and residential customers through a variety of means. In some cases, homebuilders include a weather station in a new housing development, spreading both the capital and ongoing costs across a large number of users.
Some products, such as WeatherTRAK, provide weather data to buyers by means of an annual or monthly subscription. In other instances, water purveyors or government agencies broadcast the data collected from weather stations, because the cost of obtaining the data is fairly nominal for a municipal water district or private water company. For customers who purchase the appropriate receiver, such as Rain Bird’s ET Manager, to connect to their irrigation controllers (for which the water purveyor may offer a rebate), such an arrangement makes the advantages of ET-based irrigation control available to those who wouldn’t be able to afford their own weather station.
Return on investment of such systems depends on such factors as the size of the property and the previous watering schedule, notes Shaw Merrill of Irrisoft, a subsidiary of weather station maker Campbell Scientific. But Merrill notes that some of Irrisoft’s customers have seen their investment pay off in just under three months, although he says typically return on investment would probably take one to two years for a typical home on a quarter-acre lot experiencing a 30% to 50% savings in water use.
For property owners or managers who may not wish to pay the subscription fees sometimes necessary to obtain weather data or who may not have a signal provider in their area transmitting such data, there are also ET controllers, offered by makers such as Accurate WeatherSet and Weathermatic, that use data from an onsite sensor. As opposed to the complexity of some other weather-based irrigation systems, Matt Piper of Weathermatic explains that users of his company’s SmartLine product simply have to provide basic data—their ZIP code, the kind of sprinklers they’re using (drip, etc.), and the type of plants being watered—and the system then determines how much water needs to be used and how often.
With the multitude of ET-based irrigation control products on the market, the Irrigation Association (IA) has formulated an independent testing protocol for “smart” controllers. The tests are conducted by the Center for Irrigation Technology at California State University–Fresno, and manufacturers who give their authorization have the results of their products’ tests posted on the IA’s Web site. Stephanie Tanner, an environmental engineer with the EPA’s WaterSense program, says the agency is “closely watching” the IA’s testing program. Eventually, according to Tanner, the EPA wants to set performance standards for these devices that would allow them to earn an agency designation as “water efficient.”
Meanwhile, in February, the program awarded its first WaterSense label to two Irrigation Association programs: Certified Irrigation Designer and Certified Irrigation Contractor. To win the WaterSense designation, says the EPA, “IA’s certification programs must test for the ability to design, install, and maintain water-efficient landscape irrigation systems, including tailoring systems to the surrounding landscape, selecting water-efficient equipment, tracking local climate conditions, and developing appropriate schedules for watering.”
Fiona Sanchez, a conservation supervisor with California’s Irvine Ranch Water District (IRWD), expresses concern that a lack of “easily accessible and accurate data”—needed in order for ET-based controllers to operate effectively—limits the use of such devices. According to Sanchez, the California Department of Water Resources and the University of California–Davis are partnering to increase the weather station data available in the state, particularly in urban areas. With support from large water agencies throughout the state, the IRWD—a public water purveyor—has just begun talks with manufacturers about producing a receiver for the newly available data in an accepted format. While it remains to be seen how readily manufacturers will participate in development of a product that could cut into their market share, Sanchez notes that the makers “have been very supportive” so far. “We see the value of these products in saving water and reducing runoff,” says Sanchez. “We want better coverage throughout the state and a reduction in the cost.”
Businesses or homeowners who choose ET-based controllers may be in the vanguard now, but they’ll have a lot of company soon, if emerging trends continue. In California, the Municipal Water District of Orange County launched its SmarTimer rebate program in October 2005 with federal, state, and local funding. Currently, the imported water wholesaler offers rebates to eligible customers on a number of different ET-based controllers. The district’s Berg, engaging in a little water conservation wordplay, explains that the MWDOC initiated the rebate program for irrigation controllers because the Orange County market was already “saturated” with low-flow toilets (more than 70% market penetration) and showerheads (more than 80%). By contrast, explains Berg, more than half of the county’s 675,000 single-family residences have traditional, clock-based irrigation timers.
Giving incentives to business owners and homeowners to switch to “smart” controllers represents a way for the district to realize “quantifiable and reliable water savings that we just haven’t seen with education-based programs,” says Berg. As of December 2006, nearly 2,000 users (both single-family residences and commercial) had made the change, and the district has obtained funding to extend the program through 2010. To maintain their products’ eligibility for the district’s rebate program, Berg says manufacturers must submit their products for testing by the Center for Irrigation Technology by July of this year and release the results. Eventually, Berg adds, the district will also want controllers in the program to meet certain minimum performance standards.
Some jurisdictions—such as the City of Frisco, TX—are going beyond incentive programs and enacting laws mandating the use of “smart” controllers. As part of its new water conservation ordinance, Frisco (population 93,346) now requires that ET-based controllers be installed for new landscapes for all residential and commercial properties. The ordinance, which took effect in December 2006, will also apply to existing developments that undergo expansions of 30% or more.
Darell Bagley, senior landscape architect for the city, explains that the Frisco region of Texas—north of Dallas—receives average annual rainfall of 36 inches. Nevertheless, he says, with the population growth it’s experienced—a 277% increase since 2000—”even in years with normal precipitation, water’s still an issue.” As it happens, the area has just been through its worst drought in 50 years and is still subject to water restrictions—conditions that helped the city make its case for the new requirements, despite opposition from homebuilders.
Drafting the ordinance—in consultation with residents, developers, and landscape professionals—and getting it passed was a lengthy process, taking about three years, but Bagley notes that several other jurisdictions in the North Central Texas Council of Governments have expressed interest in adopting similar ordinances.
Jurisdictions looking to craft water efficiency ordinances will soon have other models besides Frisco’s to consider. California recently enacted legislation requiring the Department of Water Resources to update the state’s model water efficiency ordinance and distribute it to local agencies by early 2009. Local jurisdictions in turn will have until the beginning of 2010 to adopt the model ordinance or their own, equally effective one, and such ordinances must include provisions for the use of weather-based irrigation controllers.
Moreover, the law mandates the Department of Water Resources to develop performance standards and labeling requirements for landscape irrigation equipment, including irrigation controllers. Starting in 2012, all landscape irrigation controllers sold or installed in California will have to comply with the performance standards and labeling requirements adopted by the state. “Water conservation is the one approach to addressing water supply that works in every area of California,” explains Assemblyman John Laird, who authored the bill, “and it is one of the more cost-effective ways to stretch our water supplies. Also, because the pumping, movement, and storage of water is energy-intensive, this bill should be considered part of California’s unfolding strategy to combat climate change.”
The radio telemetry technology used by many weather station systems has other applications for water conservation as well. Steve Grove, North America sales manager for Austria-based Adcon Telemetry, explains that radios placed on meters along water supply lines in Europe are helping water suppliers detect leaks much earlier than they were able to in the past—in a matter of days, rather than months, when the leaks tend to be smaller. The savings, says Grove, have been so substantial that the systems pay for themselves.
Whether by government mandate or simply because of an increasing conservation ethic among consumers, it appears that the demand for weather-based irrigation control systems will only continue to rise. Weather-based irrigation systems have evolved from being an expensive means to save water to more affordable systems that not only conserve water but also can play a role in reducing runoff, pollution, and global warming.