Residential outdoor water use in the United States accounts for nearly 9 billion gallons of water each day, mainly for landscape irrigation. Experts estimate that as much as 50 percent of this water is wasted due to overwatering caused by inefficiencies in irrigation methods and systems.
But that’s just an average. As summer temperatures start to skyrocket, so does residential water use. Water utilities refer to the hotter and typically drier months of June through August as “peak season,” or the time of year when customers compensate for increased temperatures and decreased rainfall by using the most water. Compounding the already hot and dry weather is the persistent drought that many areas of the country are experiencing.
Landscaping and irrigation customers might be asking how they can keep their lawns looking fresh without overwatering. Contractors can look to WaterSense labeled weather-based irrigation controllers – a “smart” technology that applies water only when plants need it – as part of the solution.
WaterSense labeled weather-based irrigation controllers, which act like a thermostat for a sprinkler system by telling it when to turn on and off, use local weather and landscape data to tailor watering schedules to actual conditions on the site. Instead of irrigating using a clock timer and a preset schedule, WaterSense labeled controllers allow watering schedules to better match plants' water needs. With proper installation, programming, and system maintenance, homeowners and businesses can replace standard clock timers with independently certified WaterSense labeled controllers, and waste less water, time and money.
Get off the clock. Advanced weather data-gathering technologies allow WaterSense labeled controllers to automatically adjust the amount of water applied to the landscape according to its needs. As outdoor temperatures increase or rainfall decreases, labeled controllers adjust watering schedules to compensate for the fluctuation. They automatically alter watering times and events based on site-specific variables, such as soil type, plant type, and local weather changes.
Using WaterSense labeled controllers instead of standard clock timer controllers can save an average home nearly 8,800 gallons of water annually. If every home in the United States with an automatic sprinkler system installed and properly operated a WaterSense labeled controller, we could save $435 million in water costs and 120 billion gallons of water across the country annually from not overwatering lawns and landscapes. That's equal to the annual household water needs of nearly 1.3 million average American homes.
WaterSense labeled controllers are available for a variety of applications appropriate for everything from small residential to large commercial systems. Some products connect to standard clock timer controllers and modify their irrigation schedules. These add-on or plug-in technologies can be added to an existing controller to make it “smart.” Stand-alone products, meanwhile, replace clock timers and have the ability to monitor weather conditions within the controller itself.
WaterSense labeled controllers can either employ onsite sensor-based control technology or use signal-based control technology. Onsite sensor-based controllers collect real-time measurements of local weather data (e.g., temperature, humidity, solar radiation) to adjust irrigation scheduling. In contrast, signal-based controllers receive a regular signal of prevailing weather conditions via radio, telephone, cable, cellular, Web, or pager technology. The signal typically uses data from local weather station(s) to create or update the current schedule for the controller.
Control with confidence and payback. There are currently nearly 70 weather-based irrigation controller models that have earned the WaterSense label. To earn the label, controller manufacturers submit their products to third-party laboratories to test whether they can adequately meet the watering needs of a landscape without overwatering. These controllers must also be able to accommodate local watering restrictions and avoid watering when necessary. They can even work in tandem with a rain sensor to avoid irrigating during a storm.
“There are so many controllers on the market,” said Kathy Nguyen, water efficiency program manager for Cobb County (Georgia) Water System. “It is a challenge to understand what controllers are designed to actually do. Having a WaterSense label allows the professional to say these controllers have been independently labeled and they have the potential to save water over standard controllers. It gives the professional a reputable resource.”
By specifying labeled controllers for their customers, contractors can become more than just a landscape or irrigation designer, and instead take on the role of “water manager,” Nguyen noted. According to Nguyen, introducing WaterSense labeled controllers can help contractors initiate broader discussions with their customers about auditing their systems, the importance of landscape zoning, or the potential need to retrofit sprinkler heads. Talking to their customers about their systems and plant water needs can differentiate an irrigation or landscape business as water-smart and make them more valuable in a competitive market.
Paul Schultz, a certified irrigation professional and WaterSense partner with Cagwin & Dorward in Novato, California, has been recommending smart controllers for years, several of which now bear the WaterSense label. “When possible, we always bring the possibility of weather-based controllers to the table,” Schultz said. “Besides their overall water savings and potential payback, they have the ability to keep plants and the rest of the landscape healthy.”
More often than not, Schultz said, despite the cost difference between weather-based and clock timer controllers, his customers are comfortable installing smart controllers. If customers aren’t sold on the technology from the beginning, he and his team will often install a scalable system—meaning that modules can be added on at a later date to make them “smart.”
Schultz has found that his customers see a quick return on investment. One customer that installed 11 weather-based controllers at a commercial site saw a 40 percent water savings when compared to previous usage and recovered the cost of the project in less than two years. And since the plants and turf were no longer subject to overwatering, the entire landscape was healthier.
A number of municipalities and water utilities also offer rebates for WaterSense labeled controllers to make them more affordable or get customers to try them. This means customers may see a return on their investment much earlier. What’s more, weather-based controllers could mean fewer call-backs and higher customer satisfaction rates for contractors, since these controllers adjust on their own—with the proper programming and management.
Put Best Management Practices in Place
For smart controllers to work as intended, there are several best management practices to keep in mind:
1. Don’t “set it and forget it.” Make sure the customer understands that no irrigation control system should be installed to “set and forget.” Users need to periodically inspect the landscape to ensure the system is performing properly.
2. Play zone defense. Zone-by-zone control successfully manages landscapes consisting of multiple areas with various watering requirements.
3. When in drought, take time out. Utilities often impose local water restrictions in drier parts of the country during “peak” season and drought periods. Although WaterSense labeled controllers are required to allow manual overrides for such occasions, it’s a good idea to keep restrictions in mind when initially programming the controller for a customer.
4. Get smart. Occasionally, a controller can lose its weather-based signal and stop operating in “smart” mode. Help customers understand the difference, and how to switch the controller back to efficient operation.
5. Set a budget. On WaterSense labeled controllers, the percent adjust or “water budget” feature allows users to adjust water applied to the landscape without changing the detailed settings in the controller’s program. Show customers how to use this simple dial or button so they can fine-tune their watering to allow more or less water to be applied to a specific irrigation zone.
Finally, while WaterSense labeled controllers can be an important component of a water-smart landscape, they cannot replace proper irrigation system design, installation, maintenance, and auditing by qualified professionals. In fact, it’s a good idea to have the entire system audited by a certified irrigation professional for inefficiencies before switching to a new controller.
WaterSense labels professional certification programs focused on water-efficient techniques. For more information and a list of professionals certified by a WaterSense labeled program, visit www.epa.gov/watersense/outdoor/irrigation_professionals.html. For more information about WaterSense labeled weather-based controllers, visit www.epa.gov/watersense/outdoor/tech.html.
The author is an environmental protection specialist with the EPA