Relieve Pressure and
Reduce Water Waste
From Spray Sprinklers
Many irrigation systems operate at water pressures that are higher than what
the manufacturer recommends, which can result in excess and uneven watering.
Spray sprinkler bodies (SSBs) that have earned the U.S. Environmental Protection
Agency (EPA) WaterSense® label can reduce water waste and improve plant health
by regulating water pressure at the spray nozzle. This document describes the
characteristics, benefits, optional features, and installation tips for WaterSense
labeled SSBs, and how SSBs fit into a water-smart landscape.
Background
Most spray sprinklers have recommended operating
pressures between 30 pounds per square inch (psi)
and 45 psi. Operating a sprinkler system at a pressure
higher than recommended can cause significant water
waste, due to excessive flow rates, misting, fogging,
overspray, and uneven coverage.
High water pressure can be caused by high supply
pressure or changes in landscape elevation. High
pressure can be
managed by installing
pressure regulators
on the main line near
valves that separate
irrigation zones or
sprinkler bodies
that have internal
pressure regulation.
The location and
number of pressure
regulators will depend
on where a system
experiences high
pressure. A pressure
regulator on the main
line will reduce incoming
supply water pressure for
the entire system. Some
systems will require multiple
pressure regulators along
the path of water. Some
sprinkler bodies include an
internal pressure regulator
that is housed inside the
stem. This mechanism
is engaged when water
entering the sprinkler body
is at a pressure higher than
the manufacturer-specified
regulation pressure. This
"integral pressure regulator"
allows the sprinkler body to work at or near its optimal
operating pressure, resulting in a consistent flow of
water, generating the appropriate water droplet size,
and providing a more uniform distribution of water
across the landscape.
High pressure in irrigation systems is more
common than one would expect. For example,
based on irrigation audits conducted by Utah State
University Extension and by the Center for Resource
Conservation in Boulder, Colorado, 63 percent of
Operating under too much
pressure can cause misting,
fogging, overspray, and uneven
coverage. Courtesy of the Irrigation
Association.
Operating under too much
pressure can cause misting,
fogging, overspray, and uneven
coverage. Courtesy of the Irrigation
Association.
Internal structure of a spray
sprinkler body. Courtesy of
the Irrigation Association.
EPA-832-F-20-002
PHONE (866) WTR-SENS (987-7367) WEBSITE www.epa.gov/watersense EMAIL watersense@epa.sov February 2020

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irrigation systems in those regions operate at water
pressures higher than 30 psi. Installing WaterSense
labeled SSBs in an irrigation system for the average
household, operating at or above 60 psi, can save
nearly 5,600 gallons of water per year.
Why Install WaterSense Labeled
Spray Sprinkler Bodies?
There are many benefits to installing WaterSense
labeled SSBs:
•	Reduce overwatering and improve plant
health: By using integral pressure regulation to
ensure the intended amount of water is applied,
WaterSense labeled SSBs reduce the likelihood
of overwatering, resulting in a healthier, more
attractive landscape.
•	Pay for themselves with avoided water
costs: Replacing existing sprinkler bodies with
WaterSense labeled models throughout an in-
ground irrigation system operating at or above
60 psi can save a home with an average sized
residential landscape more than $60 per year in
water and sewer costs, resulting in a payback
period of 2.1 years.
•	Make installation a snap: WaterSense labeled
SSBs are installed the same way as a standard
model. Both installation and maintenance are
simple and straightforward.
Optional Features
In addition to integral pressure regulation, sprinkler
bodies can also come with optional features such as
flow reduction capabilities, integral check valves, and
caps to indicate reclaimed water use. Flow reduction
prevents water from flowing when a sprinkler is
broken or damaged. An integral check valve prevents
water from flowing out the bottom of sprinklers at
Savings All Season
Installing sprinklers with flow reduction could
save more than 25,000 gallons of water and
$280 in water costs over a six-month irrigation
season.
Performance Under
Pressure
WaterSense labeled SSBs
are tested and independently
certified to meet EPA's criteria for efficiency and
performance, as described in the WaterSense
Specification for Spray Sprinkler Bodies.
Labeled SSBs are tested for a consistent
flow rate under varying upstream water
pressures that are higher than ideal
operating pressures for sprinkler nozzles.
By testing for performance related to flow
rate, WaterSense labeled models have
demonstrated that they will perform under a
variety of high-pressure conditions.
• WaterSense labeled SSBs are also tested to
ensure that performance is maintained under
low-pressure conditions.
lower elevations. Both are beneficial for operating an
efficient irrigation system.
Design and Installation
Even the most water-efficient components cannot
compensate for poor irrigation system design,
installation, or maintenance. A holistic approach will
help customers achieve the full potential of water
savings outdoors.
An irrigation system should be designed and
installed to provide the right amount of water to
plants based on plant type. When designing a new
landscape, group plants by water requirements
into irrigation zones designed to match plant water
needs. All sprinklers within a zone should have
integral pressure regulation and share the same
recommended operating pressure. This maintains
even pressure distribution and flow rates throughout
the zone, providing a uniform distribution of water and
preventing misting and overspray.
For best results, after assembling the irrigation pipe,
but before connecting the sprinklers, flush the entire
system to remove any debris that could be in the
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pipes. When installing sprinklers, as with all system
components, the connection should be secure. All
threaded connections should be wrapped with tape to
keep the connection secure and prevent leaks. Most
connections should also be glued, because the high
system pressure can push joints apart.
When installing WaterSense labeled SSBs, like any
sprinkler body, the top of the sprinkler body should
be level with the top of the soil. During operation, the
top of the sprinkler nozzle should rise higher than the
grass level so that the spray is uninterrupted. Nozzle
patterns should conform to the shape of the irrigated
area. During installation, the direction and spray
distance should be adjusted to avoid hitting any walls
or hardscapes. Spray sprinklers should be avoided
on steep slopes. If used on shallow slopes, to ensure
Figure 1
Installing sprinklers perpendicular to the ground allows for
head-to-head coverage and an even distribution of water
across the landscape.
even coverage, sprinklers should be installed such
that they are oriented perpendicular to the surface of
the ground (see Figure 1).
For maximum efficiency, sprinklers should be
placed so that the spray of one sprinkler reaches
the adjacent sprinkler. Ensuring that all sprinklers in
a zone can maintain consistent pressure and flow
makes even spacing and head-to-head coverage
easier to achieve and avoids gaps in irrigated areas of
the landscape (see Figure 2). Designing your system
for head-to-head coverage includes selecting the
correct nozzle, which is just as important as selecting
a WaterSense labeled SSB. Differences in nozzles
are based on discharge angle, pattern, and distance.
Figure 2
The top image represents a system operating at high pressure
without integral pressure regulation. The bottom image shows
the benefits of pressure regulation: consistent flow, reduction in
misting and overspray, and improved coverage.
Exact specifications for sprinkler body spacing should
be included in the manufacturer's literature.
Maximizing Outdoor Water Savings
While WaterSense labeled SSBs help reduce water
waste when pressure is too high, there are other
components of an irrigation system that can improve
water savings. For systems where irrigation events
are scheduled using a standard clock-timer controller
watering at set intervals, irrigation will occur whether
plants need it or not. WaterSense labeled weather-
based irrigation controllers : WBICs) use local weather
Weather-based irrigation controller Courtesy of Rachio.
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Don't Lose Your Head
Foot traffic, landscaping equipment, or other
machinery can easily break sprinklers and cause
water to leak or spray uncontrollably. A broken
or missing sprinkler head can waste as much as
1,000 gallons of water per week!
data and landscape conditions to apply water only
when plants need it.
Since smart irrigation is only one piece of the puzzle
when it comes to reducing outdoor water waste, here
are a few more ideas to keep in mind when creating a
landscape or irrigation system:
•	Select plants based on the local climate. Plants
native to the region are accustomed to local
weather patterns and require less irrigation.
•	Establish healthy soils to promote deep root
growth and store water,
•	Create cycle-soak schedules if water begins to
pool on the landscape surface. Dividing irrigation
cycles into shorter runtimes allows water to soak
into the landscape between cycles.
•	Consider soil moisture-based irrigation control
technologies, which water plants based on their
needs by measuring the amount of moisture in the
soil and tailoring irrigation schedules accordingly.
•	Install microirrigation around trees and
shrubs; by allowing water to seep into the soil,
this technology better irrigates the root zone of
plants, where they need water most.
•	Winterize during the cold months to eliminate the
chance of cracks and leaks caused by freezing.
Winterizing uses air pressure to remove all water
from inside the pipes. Note: If any sprinklers are
installed using the side inlet, instead of the bottom
inlet, winterizing will only remove water to the
depth of the side inlet, and any water below that
inside the sprinkler body needs to be manually
removed
Resources
EPA offers a wide variety of information about water-
smart landscaping and irrigation, as well as resources
to find WaterSense labeled irrigation products and
professionals certified by a WaterSense labeled
program. Here are just a few resources:
•	Find irrigation professionals certified by
WaterSense labeled programs: https://www.epa.
gov/watersense/irriaation-pro
•	WaterSense Product Search Tool (including SSBs
and WBICs): https://www.epa.aov/watersense/
product-search
•	Watering tips (including Sprinkler Spruce-Up):
https://www.epa.aov/watersense/waterina-tiPS
•	Irrigation Association's Landscape Irrigation Best
Management Practices: https://www.irriaation.
ora/IA/Advocacv/Standards-Best-Practices/
Landscape-lrriaation-BMPs/IA/Advocacv/
Landscape-lrriaation-BMPs.aspx
For more information about
smart outdoor water use, visit
https://www.eDa.cov/watersense/outdoors.
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