a
Optional Water Efficiency Measure: May contribute to the 30 percent water efficiency requirement,
depending on the chosen WaterSense® Approved Certification Method (WACM).
ilk
III
UNDERSTAND
WaterSense labels two types of irrigation
controllers:
o Weather-based irrigation
controllers (WBICs) use local
weather and landscape conditions to
tailor watering schedules. WBICs can
obtain weather data from onsite
weather sensors and/or signals from
local weather stations,
o Soil moisture-based irrigation
controllers (also known as soil
moisture sensors or SMSs) monitor
moisture levels in the soil to prevent
irrigation when water is not needed.
An SMS is comprised of a sensor
mechanism (which stays in contact
with the soil and measures the
amount of moisture) and an interface
device (which communicates the
reading from the sensor mechanism
to the controller).
Both types of WaterSense labeled
controllers can be purchased as stand-
alone controllers. They can also be
purchased as an "add-on" or "plug-in"
device that can upgrade a clock-based
controller.
The diagram at right illustrates the
difference between the two irrigation
controllers.
BUILD
SPECIFY and INSTALL a WaterSense
labeled WBIC or SMS. Use the
WaterSense Product Search Tool at
www.epa.gov/watersense/product-
search for reference.
Real-World Results
Read WaterSense's reports on weather-based irrigation
controllers (www.epa.gov/sites/default/files/202Q-
05/documents/ws-products-irrigation-outdoor-wbic-mini-
report.pdf) and soil moisture-based irrigation controllers
(www.epa.gov/sites/default/files/2021-04/documents/ws-
outdoor-products-sms mini-report.pdf) to learn more
about how the products function, guidelines for
programming, and how to help homeowners maintain
long-term water savings. They can also help a builder,
irrigation professional, or homeowner decide which type
of WaterSense labeled irrigation controller is best for the
landscape.

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WORK with an irrigation professional certified by a WaterSense labeled program to install the irrigation
controller. These individuals are trained to install these devices and program them to work properly.
Use WaterSense's Find a Pro tool at www.epa.gov/watersense/find-pro to find a certified professional
in your area.
If installing an irrigation controller yourself, use the following guidelines:
o FOLLOW the manufacturer's installation
instructions found in product packaging or
online. Manufacturers may also provide training
on installation and operation through irrigation
distributors or retailers,
o PROGRAM the controller as described in the
instructions. Note that that the initial period of
landscape establishment may require more
water, but the device should be reprogrammed
for water efficiency once plants are established,
o MONITOR the landscape after initial installation
fo r seve ra I wee ks to loo k fo r d ry o r ove rly wet
areas. Adjust the controller accordingly,
o ENSURE that the sprinklers are working properly and there is no overspray onto adjacent areas. The
irrigation controller will not provide expected savings if sprinklers are malfunctioning,
o PROVIDE information to the resident on properly programming the irrigation controller from the
manufacturer or from WaterSense's Watering Tips web page atwww.epa.gov/watersense/watering-
tips.
There are additional installation considerations for soil moisture sensors:
o INSTALL the sensor in the area of the landscape that requires the most frequent irrigation (e.g., turf
with minimal shade). Place the sensor mechanism in the root zone of the plants,
o USE more than one sensor mechanism for large landscapes. Place each sensor in a separate
irrigation zone,
o CALIBRATE the sensor mechanism according to the manufacturer's recommendations,
o ENSURE that the SMS and rain sensor are wired in series (as opposed to in parallel), if a rain-
sensing device is also installed. See the WaterSense report on SMSs at
www.epa.gov/sites/default/files/2021-04/documents/ws-outdoor-products-sms mini-report.pdf
for more details on installation.
VERIFY
CONFIRM that the irrigation controller is WaterSense
labeled. Use the WaterSense Product Search Tool at
www.epa.gov/watersense/product-search to confirm
that the irrigation controller installed has earned the
WaterSense label.
CHECK for signs the landscape is being over- or
under-watered by looking for soggy areas, brown
spots, or wilted plants. Work with the builder or irrigation professional to adjust the irrigation controller.
*NOTE: Consult with the Home Certification Organization for specific verification protocols.
Image courtesy of Rachio
Learn More
Go to the WaterSense Labeled
Controllers web page at
www.epa.gov/watersense/watersense-
labeled-controllers to learn more.
This technical fact sheet is part of EPA's Technical Reference Manual for
WaterSense Labeled Homes. For the full document and other tools and	EPA-832-F-23-016
resources for homes, visit www.epa.gov/watersense/tools-and-resources.	July 2023

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