Written by Anish Desai 6:30 pm Column, IAPMO R&T - WaterSense

WaterSense-Certified Spray Sprinkler Bodies Prevent Waste, Ensure Proper Coverage

Representing roughly 30 percent of the average U.S. household utilization of water, outdoor applications are estimated to be 9 billion gallons per day for a total of 3.2 trillion gallons over the course of a year. With significantly higher amounts used in arid parts of the country, most of this water is used for landscape irrigation. 

Residential landscape irrigation systems frequently incorporate standard spray sprinkler bodies at locations where the system pressure exceeds their design limitations. As a result, they deliver uneven and insufficient coverage while also wasting significant amounts of water. 

WaterSense-certified spray sprinkler bodies are designed to prevent this with built-in pressure regulation that provides a consistent flow of water to sprinkler heads. Water can then be applied evenly across the landscape in a way that prevents waste and ensures proper coverage. 

The average residential irrigation system operating at 60 pounds per square inch and using 50,500 gallons of water per year could save about 5,600 gallons annually with 

WaterSense-labeled spray sprinkler bodies. 

Exchanging every spray sprinkler body in the nation that operates at pressure exceeding its design specification with these could conserve more than 31 billion gallons per year. 

Certification Criteria 

Flow Rate Requirements 

To comply with EPA’s water efficiency requirements, the product must meet two flow requirements: 

  • Maximum flow rate at any tested pressure level: the percent difference between the initial calibration flow rate (as described in Appendix B of the specification) and the maximum flow rate at any tested pressure level, averaged for the selected samples at the test pressure levels where the maximum flow rate occurred, shall not exceed +/- 12.0 percent. 
  • Average flow rate across all tested pressures: the percent difference between the initial calibration flow rate (as described in Appendix B of the specification) and the flow rate at each tested pressure level, averaged across all pressure levels and all selected samples shall not exceed +/- 10.0 percent. 

General Sprinkler Body Requirements 

In addition to meeting water efficiency and performance requirements, the specification requires conformance with Section 302 of ASABE/ICC 802-2014, which addresses general design and health and safety requirements for sprinklers (and bubblers). This section establishes criteria related to elements such as rated temperature, inlet connections, filters and strainers, servicing, adjustments, burst pressure, check valve function, and pressure regulation. 

Note: Although WaterSense initially intended to develop a specification for spray sprinkler nozzles as well, the program made the decision to stop work on that component due to comments received through the Notice of Intent (NOI) process. Should the program decide to develop a specification for this product category in the future, it will issue a new NOI. 

All statistics from US EPA WaterSense website 

Anish Desai
Senior Vice President of Product Certification at IAPMO R&T

Last modified: May 8, 2024