Nozzles’ new norm

Learn what the EPA’s WaterSense standard for spray sprinkler nozzles means for the industry.
Photo: RainBird

Staying informed about the latest developments in irrigation technology and standards is crucial for contractors. The U.S. Environmental Protection Agency’s WaterSense program is proposing new benchmarks with its specifications for spray sprinkler nozzles. Currently, there are no current federal standards that regulate water use or performance of spray sprinkler nozzles. Although WaterSense is a voluntary program, states are increasingly using it to establish state regulations. This initiative could redefine water use and efficiency standards across the country.

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Photo: Hunter

Advancing WaterSense standards

The WaterSense program, initiated by the EPA in 2006, focuses on water efficiency across various sectors, including irrigation. It establishes performance standards for water-using products, such as spray bodies, and the program’s label helps consumers and businesses identify and choose efficient products.

For spray sprinkler nozzles, the notice of intent to create a specification was filed in December 2022.

This is the second time WaterSense has attempted to set a standard for spray sprinkler nozzles, with the first attempt coinciding when it set a standard for spray sprinkler bodies. At that time, EPA decided to only move forward with specification development for spray sprinkler bodies.
Joanna Kind, senior environmental scientist at Eastern Research Group, presented the case for the specifications at a meeting in December 2022, including that it is estimated that high-efficiency spray sprinkler nozzles have the potential to use approximately 10% less water than standard spray nozzles, based on WaterSense’s review of recent studies on real-world water savings.

Photo: Hunter

According to the EPA’s estimates, the average household could save about 2,400 gallons of water annually by replacing standard spray nozzles with high-efficiency spray sprinkler nozzles.

For contractors, as Nathan Bowen, Irrigation Association advocacy and public affairs vice president, explains, “a WaterSense specification can be an important tool for informing consumers about water-efficient products and can create opportunities for irrigation contractors to engage clients about more efficient product options. But it is critical to get a specification right, and that is why we are working closely with EPA’s WaterSense program to ensure the perspectives of the entire irrigation industry are taken into account as it considers developing a specification for spray sprinkler nozzles.”

This shift impacts contractors directly, as it ultimately changes the types of products available in the marketplace. Understanding these specifications is not just about selecting nozzles; it’s about grasping the technology behind them and their environmental and business implications, says Bowen.

Draft specifications:
A closer look

The WaterSense draft specifies criteria for landscape irrigation spray sprinkler nozzles to earn a label under the EPA’s program.

It focuses on nozzles attached to spray sprinkler bodies lacking components to drive nozzle rotation during operation and without internal control valves. The specification does not apply to products used exclusively in agricultural irrigation systems or those like bubblers and microirrigation devices.

Key aspects of the draft include general requirements like meeting ASABE/ICC 802 Sprinkler and Bubbler Design Requirements, performance criteria such as a maximum allowable difference between tested and rated distances of throw, and an application rate of 1.2 inches per hour or less. Uniformity and matched precipitation are also referenced, with detailed guidelines on how these should be measured and achieved.

Testing was conducted to develop the specification by Michael Dukes, PhD, University of Florida professor of irrigation and director, University of Florida/IFAS Center for Land Use Efficiency.

Bowen highlighted that many water agencies have been pressing WaterSense to develop a specification as a way to help bring clarity to their rebate programs. Designing a rebate program around a WaterSense label is a more straightforward approach for an agency, compared to managing extensive lists of individual products, he says.

Photo: Hunter

The contractor’s perspective:
Adapting to change

Brian Vinchesi, CGIA, CIC, CID, CLIA, CLIM, CLWM, founder and president of Irrigation Consulting Inc., Nashua, New Hampshire, highlights the practical implications of these changes: “The label, as proposed, will reduce the contractors’ available nozzle selections considerably.”
According to Vinchesi, contractors will need to rethink their sprinkler layouts and nozzle choices, potentially shifting toward more rotary sprinklers or more closely spaced spray sprinklers with lower gallons-per-minute nozzles.

Many of the higher precipitation rate spray nozzles that contractors use will not be labeled. “Most likely, no variable arc nozzles will be labeled. It will be interesting to see how many multi-stream, multi-trajectory rotary nozzles will be able to earn a label. It may be manufacturer-specific as some will and some won’t.”

Vinchesi emphasizes that the shift toward WaterSense-labeled products is not just about product adoption but also involves a deeper understanding and application of efficient irrigation principles. He points out that this significant change will necessitate extensive education for distributors, contractors, and even irrigation designers, acknowledging that the transition may be challenging to implement.


There will be a learning curve to figure out how to meet the criteria.
– Brian Vinchesi, Irrigation Consulting


“Precipitation rates are not something your average contractor is used to dealing with, nor uniformity,” says Vinchesi. “There will be a learning curve to figure out how to meet the criteria. Buying the WaterSense-labeled product will be a big step, but you can void its benefits very quickly by spacing the sprinklers wrong or not having the correct operating pressure for the nozzles.”

The lower precipitation rates will increase overall run time, which will need to be taken into consideration. Longer water windows may require a larger water supply. Most contractors are not necessarily well versed in precipitation rates as they are more used to time scheduling — this many minutes for sprays and this many minutes for rotors — which is still based on precipitation rate, but they will be more diverse with the label.”

The future landscape:
A ripple effect across states

The draft specification could end up as more than a voluntary label program; it could become the blueprint for state-level standards.

“It’s important for contractors to be aware of the development of these specs and have a seat at the table as they’re crafted, as they could shape future regulations in the states,” says Bowen. “This isn’t just about the proposed new specification. The broader implications are significant, potentially reshaping water-related policy at the state level.”

Photo: RainBird

The Irrigation Association is actively involved in developing these specifications and providing resources and guidance for contractors. For the latest updates and detailed information, contractors are encouraged to visit the IA’s website and stay connected with industry developments, says Bowen.

“In light of the evolving WaterSense spray sprinkler nozzle specifications, the IA remains steadfast in its engagement with the EPA’s WaterSense program,” says Bowen. “Our proactive involvement ensures that the voice of the irrigation industry is not just heard but is influential in shaping these standards. We are committed to guiding our members through these changes, ensuring that the industry not only meets but exceeds these benchmarks, reinforcing our dedication to thoughtful water resource stewardship and efficiency.”

The process of finalizing the spray sprinkler nozzle specification is ongoing. The current stage involves collecting public comments on the draft specification. After reviewing these comments, the EPA will release a final specification, which will also be open for public feedback.

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Luke Reynolds is the content editor for Irrigation & Lighting and can be reached via email.

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