Pressure regulation has established itself as one of the most direct ways to manage water use in an irrigation system, so much so that legislatures in more than a dozen states (and more on the way) have made this technology the law. If it’s not already mandated in the state you’re doing business in, it could be very soon.
As many regions around the U.S. are forced to deal with water restrictions due to persistent drought conditions or depleted aquifers, pressure-regulating components represent minor upgrades with major water-saving upsides. But the bottom line is that using this technology when designing a system just makes sense.
Pressure management has always been a critical component of any successful irrigation system, says Arianne Williams, product manager at Rain Bird, Azusa, California. Historically, low pressure has been indicative of a maintenance issue, system damage or even a poorly conceived design. This subsequent loss in irrigation efficiency results in everything from sprinkler heads that fail to pop to poor spray patterns, leading to excessive run times and the telltale doughnut pattern featuring a lush green center surrounded by a brown, dying circle of turf.
Irrigation systems with excessive pressure are just as inefficient. “A lot of the time, people think the higher pressure they have, the more effective the irrigation system is going to be,” says Williams. “That’s not actually the case when it comes to irrigation.”
In addition to the toll this scenario has on irrigation components, systems under high pressure tend to release a spray as a fine mist instead of a weighty droplet. This impacts application uniformity and drastically cuts efficiency as the misty microdroplets of water are carried off and away in the prevailing breeze. This results in excessive run times to ensure enough water saturates the soil of surrounding turf and ornamentals already showing signs that they are in dire need of a drink.
“With PRS, since you’re reducing the misting, the water droplets are actually bigger and can reach your target area more efficiently,” says Williams. “You want something with a higher distribution uniformity — a measure of how evenly or uniformly water is applied to an area. High-efficiency and rotary nozzles have a greater distribution uniformity — greater than 70%.”
High-efficiency nozzle technology dials in the distribution uniformity. By comparison, the distribution uniformity of standard nozzles can vary between 40% and 50%, she says. Combined in tandem with PRS, the water savings begin to add up.
The ability to hit targets more efficiently and accurately can scale back a 45-minute run time down to 30 minutes. “That’s really where you start seeing the water savings come in,” Williams adds. “We’ve done studies where you take [an irrigation system’s] pressure from 70 psi down to 30 psi, and you can save up to a gallon of water a minute. A site may have 100 spray bodies, so water savings and conservation can add up quickly.”
The impact of pressure regulation upgrades is significant. For example, researchers from Oklahoma State University partnered with Oklahoma City to retrofit 157 spray heads in several median strips throughout the city. The upgraded components regulated the pressure at 30 psi, with an output of 153 gallons per minute, which was a 62 gpm reduction in water, according to a 2019 fact sheet published by the university.
And operating on an 18-minute cycle, the pressure-regulated system saved around 16,700 gallons of water, according to the university’s report. In addition, researchers estimated that a typical residential irrigation system with around 40 spray heads could save as much as 5,000 gallons of water per month.
Clearing up myths
There’s a fair amount of misconception regarding pressure regulation in irrigation systems, says Chris Keating, a district sales manager for The Toro Company, Bloomington, Minnesota.
First, pressure-regulating technology is not a new innovation, and it’s been available for irrigation systems for at least the last 35 years, Keating says. It just hasn’t been adopted unless specified by an irrigation consultant or designer.
“This is not a new concept,” he says.
Typically, its integration into designs comes down to cost. But a bit of added upfront investment can save the end user significant dollars in operational and maintenance costs over the life of the irrigation system, Keating says.
Another obstacle has been a clear understanding of how this technology is beneficial.
“Some folks have suggested, ‘Why do we need to regulate the pressure at the sprinkler when it could be done at the valve?’” he says. While that can be done, anything that happens in the system after the regulated valve can affect the operating pressure of the sprinkler and negatively affect distribution uniformity and efficiency.
Regardless if the inlet pressure exceeds the desired operating pressure, a pressure regulator guarantees equivalent operating pressure within a reasonably tight parameter. For an irrigation designer or installer, this ensures that each sprinkler in the system is operating at or near its peak effectiveness.
“Pressure regulation really enables the general installer and designer to really be good at getting close to a highly efficient system,” Keating says. “It helps us hit that target.”
What PRS doesn’t do is make a mediocre irrigation system better. “It can’t improve a nozzle’s performance beyond its inherent design capability,” Keating says. “Pressure regulation does not make a silk purse out of a sow’s ear.”
And it doesn’t add pressure to an irrigation system, which Keating says is a common misconception among irrigation pros.
“If a pressure-regulating spray head suggests a 30-psi operating range and you give it 25 pounds at the base of the head, it won’t magically increase the pressure by 5 pounds and deliver it to the nozzle,” Keating says. “Pressure regulation cannot improve low pressure. That’s on the designer. What it will do is reduce the flow and pressure to a desired optimum range to help us achieve what was intended by the manufacturer as proper operating parameters.”
Getting on board
The writing was on the wall for Eric Weston, CIC, owner of Acquaviva Irrigation, Yarmouth Port, Massachusetts. As legislators began to make news finalizing PRS laws in various state capitals, he moved to get in front of eventual legislative mandates in his home state and adopted PRS as his standard practice.
“I’ve always believed it’s really, really important to stay current with trends and the advantages of the latest technology, especially if it can improve water efficiency and save my clients money,” he says. “So, a few years ago, when I heard that [PRS laws] were coming, I made it a standard practice for myself so that customers were accustomed to it before it became mandated.”
A large percentage of Weston’s business is overhauling existing residential irrigation systems, which has allowed him to create a niche in his Cape Cod market, which must manage sandy soils. Most of his work is troubleshooting older systems to correct poor uniformity and poor coverage. And while the pressure-regulating components were nearly double the cost of standard irrigation components, he says the cost jump really wasn’t an issue with clients.
“Something I’ve always tried to market and explain to my customers is don’t hire me to get the best deal because you’re not going to get the cheapest price,” he says. “Hire me because you’ll get the best coverage, the best water efficiency and, ultimately, you’ll have the best plant health.
“In the grand scheme of things, I don’t see it as having a huge impact on the overall cost of the irrigation system,” Weston adds. “It’s well worth the cost to achieve more uniform coverage. And it’s the point I’ve tried to explain to my clients that I’m not looking to put the water down quickly, but rather I’m looking to put it down as evenly as possible. I tell clients the results will speak for themselves, and that’s something that most people can understand.”
Once the PRS law was enacted, it provided Weston with new business opportunities.
“Cape Cod is a single-source aquifer … and we’re all pulling from the same source,” he says. “The past three years, we’ve had water restrictions in place as it became apparent to people that we had to be smarter about the ways that we water.”
Although relatively minor, the price increase has been an issue for IA-certified contractor Mike Palotta’s clients.
Palotta, CIC, CID, CLIA, the owner of Palotta Lawn Irrigation, Bedford Hills, New York, has been troubleshooting issues and upgrading systems with check valves instead of PRS components mainly because his residential and commercial clients (including athletic fields and golf courses) balked at the price increases. He offered PRS as a systems upgrade, but very few clients were willing to consider the extra cost. However, he acknowledges this will change when the law is enacted in New York in 2024.
No one else in his market is using PRS, which means that he prices himself out of work when he advocates for it. “Even though you’re only looking at a $2.50 to $3 increase per component, [the price] begins to add up if you’re adding that to a system with 100 heads,” he says. “It all comes down to the dollar, right?”
Palotta suspects most of his clients will resist PRS upgrades until their existing irrigation system breaks down and requires significant maintenance or even replacement.
A bit further south, Russ Jundt, CIC, founder and president of Conserva Irrigation, Richmond, Virginia, has seen that residential and commercial clients are receptive to pressure-regulating technology, regardless of whether it’s state law. PRS spray bodies are also a standard protocol for Conserva. For multiple years, Jundt’s team has adopted pressure-regulated spray bodies with check valves combined with an efficient nozzle or rotator as the only installation option for clients. No matter what type of system is being installed, this approach guarantees that it will incorporate regulating technology, making it easier for clients to choose an efficient option.
“Likewise, whenever a spray body is installed during a service call, the same is true,” he adds. “Similar to Henry Ford’s [motto], you can choose any color Ford vehicle you want, as long as it is black. Conserva has taken that same stance.”
While this may appear limiting, Jundt says this stance has set them apart from their competitors in two significant respects. First, it sends the message that they only do what’s best for their customers and for the environment. And second, he says the SKU reduction and the associated economies of scale for purchasing large amounts of this SKU make the decision even more compelling and profitable from a business perspective.
“All contractors who consider themselves professionals in the landscape irrigation vertical should have no issue being proactive and taking the same stance as Conserva,” he says. “Once you become educated on the topic, the only path forward is to install [pressure-regulating] heads, regardless of regulation. And the same holds true, in my opinion, for only installing checked heads, efficient nozzles and smart controllers with rain/freeze sensors.
Once you have seen behind the Oz curtain, you can never go back to where you started.”
