EPA
A
Water Sense
Saving Water With lVlicroirrigation:
A Homeowner Guide
AEPA

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Table of Contents
What Is Microirrigation?	1
Why Microirrigate?	1
How Can Microirrigation Work on My Landscape?	2
Tips for Do-lt-Yourselfers	3
Go With a Pro	5
When and How Much to Water	5
Maintaining Microirrigation	6
Cover Photos
7.	WaterSense Landscape Photo Gallery
2.	Photo courtesy of Hunter Industries Incorporated
3.	Photo courtesy of Hunter Industries Incorporated
4.	Photo courtesy of Hunter Industries Incorporated
5.	Photo courtesy ofTheToro Company
6.	WaterSense Landscape Photo Gallery
7.	WaterSense Landscape Photo Gallery
8.	Photo courtesy of Rain Bird Incorporated

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The U.S. Environmental Protection Agency's WaterSense® program labels products, homes,
and programs that help consumers save water. Along with the labeled products, another way
to save water outside is to install or retrofit a landscape irrigation system with microirrigation
technology. The following guide provides a brief overview of the technology and tips for
homeowners interested in using microirrigation; more detailed information can be found in
Adding Microirrigation to Your Services: A Mini-Guide for Irrigation Professionals, which is
available at www.epa.gov/watersense/microirrigation.
What Is lVlicroirrigatiori?
Microirrigation is a low-pressure, low-flow-rate
irrigation that helps reduce overwatering on
residential and commercial landscapes. Also
referred to as low-flow, trickle, or drip irrigation,
microirrigation delivers water directly to the
root zone of plants, where it is needed most. By
delivering water more slowly and over a longer
period of time, it allows the water to better
penetrate soil and reduces runoff.
A microirrigation system can be incorporated
into a newly designed landscape, installed in
an existing landscape, or added to a landscape
that already has an irrigation system. While it
can be used in most landscapes, it is best suited
for plants and trees that are spaced somewhat
apart, as opposed to turfgrass on lawns,
where spray sprinkler systems provide better
coverage. Spray sprinkler irrigation is the most
common form of landscape irrigation in the
United States. If managed improperly, however,
water that comes from spray sprinklers can
form puddles, evaporate, or land in soil beyond
plant roots, causing outdoor water waste.
This guide provides an overview of the
benefits of microirrigation, where it works
best, how to use it efficiently, and tips for the
do-it-yourselfer on how to design, install,
and maintain a microirrigation system. And
if you're not the do-it-yourself type, there are
suggestions for consulting a certified irrigation
professional to ensure the system performs
well and saves water.
Because microirrigation provides water directly at the root zone of plants at a lower flow rate, it allows
the water to soak into the soil, rather than run off, and applies water only where it is needed.
Why lVlicroirrigate?
The average American home uses 30 percent
of its water outdoors, but that percentage can
be much higher in drier regions of the country.
As much as 50 percent of outdoor water can
be wasted due to runoff, wind, or evaporation,
in part because irrigation systems are not
installed, maintained, or used properly. Because
microirrigation provides water directly at the
root zone of plants at a lower flow rate, it allows
the water to soak into the soil, rather than run
off, and applies water only where it is needed.
Research indicates that microirrigation systems
use between 20 to 50 percent less water than
conventional spray sprinkler systems. Installing
a microirrigation system instead of a traditional
system can save a typical home more than
25,000 gallons of water per year.
With microirrigation, bare areas of soil or
mulch between plants are not irrigated, which
not only saves water, but reduces weed
growth. Since water does not pool and the
landscape is healthier, the need for added
herbicides or pesticides decreases. Finally,
these systems help protect local water bodies
such as streams, lakes, and rivers, because they
reduce runoff caused by the inefficient
watering that can sometimes be associated
with spray irrigation.
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How Can lVlieroirrigatiori
Work ori lVly Landscape?
Whether designing a new landscape or
developing an irrigation system for an existing
one, you can incorporate microirrigation
techniques and equipment. Even if you have an
existing irrigation system with spray sprinklers,
it can be retrofitted with microirrigation in
areas where the landscape could benefit from
direct water delivery to plant roots.
It's important to note where and on which
types of plants microirrigation works best.
The illustrations on this page describe the
landscape and plant types best-suited for
microirrigation.
Flower Beds
Vegetable Gardens
Trees and Shrubs
Container Plants
Flowers can benefit from a microirrigation
system that provides water only to the plants
that need it.
Whether circling a tree or running along
shrubbery, microirrigation can keep the roots
moist without wasting water where it's not
needed.
In rows or patches, vegetable plants can get
all the water they need while decreasing
the likelihood of weed growth and reducing
pesticide use.
Microirrigation works for potted plants too.
On balconies, porches, or decks, plants in
containers can benefit from water lines
that deliver water right to the roots.
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Tips for Do-lt-Yourselfers
There are a few things to consider when
designing and installing a microirrigation
system, including the plants in your landscape
and how much water they need. This will
help determine what types of water-emitting
devices should be used and where they should
be placed. If starting with a new landscape, the
ideal approach is to organize the plants by type
and water needs into different irrigation zones.
This is also known as hydrozoning.
Separating the landscape into irrigation
zones helps ensure that the water needs of
different types of plants are met based on plant
type, soil type, and sun exposure. To water
most efficiently, zones should group plants
with similar irrigation needs together in the
landscape. For example, turfgrass and shrubs
have different irrigation needs and should be in
different irrigation zones. However, even if you
aren't starting with a new landscape, you can
look for areas where microirrigation will work
best and tailor the devices used to different
types of plants and landscape conditions.
Following are some of the most common
types of water emission devices used in
microirrigation:
•	Drip line emitters are tubes with evenly
spaced emitters that water at a uniform rate.
•	Multiple outlet emitters have a centralized
assembly with multiple emission points.
•	Point-source emitters discharge water from
a single point that can extend from a long
pipe.
•	Microsprays spread water over a larger area,
but still at a low pressure and low flow.
When installing a microirrigation system,
it's important to have the correct number of
emission devices to deliver the right amount
of water to the different plants. The types,
number, flow rate, and spacing of emitters used
can vary by zone and plant type. Following are
a few tips for different types of plants:
Photos courtesy of Hunter Industries Incorporated
•	Flower beds and vegetable gardens may only
need one emitter per plant.
•	Shrubs often require one or two emitters per
plant, depending on their type, size, and age.
•	Trees typically benefit from multiple
microsprays or drip line emitters placed in
concentric circles below the edge of the tree
canopy.
Other considerations for installation include
the size of the pipes used, the water line
pressure, and whether filtration is needed.
More microirrigation installation tips for
experienced do-it-yourselfers are available
in WaterSense's technical guide, Adding
Microirrigation to Your Services: A Mini-Guide
for Irrigation Professionals at www.epa.gov/
watersense/microirriaation.
Drip Line Emitters
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A Bird's Eye View of a A/Iicroirrigated Landscape
Fiowers &
Small Shrubs
Zone 4

Flowers &
Small Shrubs
Zone 4
Flowers &
Small Shrubs
Zone 4
Fruit & Vegetables
Zone 1
Trees
Zone 3
Because landscapes and watering needs will
vary by region, you can consult a certified
irrigation professional (see page 5) to develop
a system that works best for your needs. For
more information about specific product
types and their installation, consult the guides
provided by product manufacturers.
The drawing below illustrates how a landscape
can be"hydrozoned"according to different
plant types with different watering needs,
and which type of microirrigation equipment
and devices might be appropriate for this
landscape. Microirrigation can be easily
installed to water a single zone near a house, or
as an irrigation system for the entire landscape.
B. Lateral Supply
Tubing
A. Controller
E. Microspray
Emitter
Photo courtesy of Rain Bird	Photo courtesy of Rain Bird
Photo courtesy ofRachio
Photo courtesy of Rain Bird
Photo courtesy of Hunter
Industries Incorporated
C. L Joint
Note: Irrigation lines can be a tripping hazard
if they cross pathways or areas with high foot
traffic. Make sure to bury lines where possible to
avoid trips and falls.

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Go With a Pro
If you are looking for a contractor to install
or retrofit a system with microirrigation,
WaterSense recommends consulting
an irrigation professional certified by a
WaterSense labeled program.These qualified
contractors have verified knowledge of water-
efficient irrigation methods and technologies.
To find a certified professional near you, see
WaterSense's Directory of Certified Irrigation
Professionals (www.epa.gov/watersense/
find-pro). Following are a few questions and
answers to help ensure your contractor installs
a high-performing, water-efficient system.
How can a contractor assist with a
microirrigation system?
The contractor will scope out your landscape
to locate the different types of plants for each
zone and determine the appropriate type and
number of emitters to deliver the right amount
of water to each. The contractor should
also check your incoming water pressure
to see if it is higher than recommended for
the microirrigation system, to determine if a
pressure regulator is needed. If you already
have an irrigation system, a contractor will
check it for leaks, clogged emitters, and other
issues. The contractor should also review your
irrigation schedule to ensure the appropriate
amount of water is being applied and address
the change in seasons, based on your region.
What should I look for in a newly
installed system?
Walkthrough the landscape with the
contractor and ask for a demonstration of
how to use the system (and program the
irrigation controller, if one is installed). Drip
emitters should be spaced properly to ensure
even distribution, all the connections should
be safely secured, and tubing should be
positioned so as not to cause a tripping hazard.
Remember to ask how often the system will
need maintenance, and if the contractor will
return to audit or repair the system or update
watering schedules.
What information will the contractor
provide?
The contractor should provide the design of the
microirrigation system, quantity and types of
emitters, and expected installation time. Your
contractor may also recommend the following:
•	For a new irrigation system installation,
some cities require rain sensors on irrigation
systems or use of reclaimed water, if available.
•	Depending on your source of water, your
system may need filtration, or connection to a
backflow preventer may be required to avoid
contaminated water entering the potable
water system.
•	If your water pressure is higher than
recommended for the system, the contractor
will likely install a pressure regulator to reduce
water waste.
•	The contractor may also recommend
replacing a clock timer on an existing system
with a weather-based irrigation controller,
which is described in more detail below.
When arid How Much to Water
Even with an efficient method such as
microirrigation, overwatering can occur when
irrigation schedules are set without careful
consideration for plants'actual water needs
and weather conditions. A certified irrigation
professional can help you develop a watering
schedule that best fits your landscape's needs,
or you can note the following factors when
scheduling watering (and make sure to revisit
your water schedule with every change of
seasons):
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•	Location, location, location. Landscape
watering needs vary by the type and location
of plants, as well as the soil in which they are
planted. Drought-tolerant plants and those
located out of direct sunlight do not need
watering as often.
•	Watch the weather. Instead of a clock
timer on your irrigation system, consider
a WaterSense labeled weather-based
irrigation controller. These independently
certified devices do the thinking for you by
using local weather and soil conditions to
determine when and how much to water
your landscape. Check if your local utility
offers a rebate on these devices at www.epa.
gov/watersense/rebate-finder and learn more
about smart controllers at www.epa.gov/
watersense/irrioation-controllers.
•	Timing is everything. Avoid watering in the
middle of the day, when the sun's heat can
evaporate water before it can be absorbed
into the soil.
•	How (old) does your garden grow? Newly
established plants need to be watered more
frequently, but once they are established,
watering frequency can decrease. As shrubs
and trees grow, they require more water to
remain healthy; however, since their roots
are better developed, much of their watering
needs can be satisfied by rainfall, depending
on the region.
Think Globally, Plant Locally
Plants native to your region often require less water. Many utilities provide lists of regionally
appropriate plants. Your local nursery, cooperative extension service, or gardening group can
also provide advice on the right amount of water for your region or plant types.
Maintaining lVlicroirrigation
Proper maintenance is essential to a water-
saving microirrigation system. Water lines at
ground level are susceptible to weed growth,
freezing, and damage from landscape work
or animals. Emitters can also become clogged
without preventive care. Following are a
few key maintenance steps for successful
microirrigation:
•	Remove weeds when needed. While direct
water delivery can help reduce weed growth,
weeds can still grow into the emitters, causing
clogs and reducing efficiency. Remove weeds
at their roots to avoid emitter damage.
•	Filter for a free flow. Emitters can also
become clogged by particles that enter the
irrigation system. Use filters to block these
particles, especially in systems fed by non-
potable water, and clean them frequently.
•	Is winter coming? At the end of the irrigation
season, and before the first freeze, the system
should be flushed of standing water, to avoid
the water lines freezing during winter months
and causing cracks in the pipes.
• Look for leaks. In addition to cracks in
frozen pipes, landscape work and animals
can damage tubing, pipes, and emitters and
cause water-wasting leaks. Flow meters and
other devices can help detect leaks before
they become a drain on your water bill and
reduce flow to plants.
With the proper design,
installation, and maintenance,
along with a little help from a
WaterSense labeled irrigation
controller and a certified
professional, your microirrigation
system can save a significant
amount of water while maintaining a healthy
landscape and enhancing your home's curb
appeal. For more information, including
more technical instructions for installing or
retrofitting a system, visit www.epa.gov/
watersense/microirrigation.
Q rnA EPA-832-F-18-003
PHONE (866) WTR-SENS (987-7367) WEBSITE www.epa.gov/watersenseEMAILwatersense@epa.gov	May 2018
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