3 A #9 9 00 3
IRRIGATION CONTROLLERS
FOR m HOMEOWNER
Recommended Water Saving features
Wafer - too precious to waste!
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Forward
This brochure is a cooperative effort sponsored by members
of both the water and landscape industry to promote
efficient landscape water use. The purpose of this brochure
is to highlight important irrigation controller features that
allow for proper irrigation scheduling. Since many people
are somewhat mystified or intimidated by these devices,
hopefully, this brochure will help when making the deci-
sion of which controller to obtain. The main point to keep
in mind is that the key to watering efficiently is to obtain
a controller that can handle diverse landscape and weather
situations and then to program it properly. This message is
so important; it is repeated again in the text.
We encourage you to contact your local water agency or
landscape company to obtain more information on how to
improve landscape water use efficiency. For any technical
assistance you may need with your controller, contact the
manufacturer.
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Importance of Irrigation Controllers
A large part of our household water use goes to watering
our landscape and many households rely on automatic
irrigation systems to accomplish this. One of the most
important components of an automatic irrigation system
is the irrigation controller (also called a rimer or clock).
The controller turns the irrigation system on and off at
the times you select. In other words, the controller
controls the irrigation system and you control the control-
ler. Having a controller with certain minimum perfor-
mance capabilities is vital to efficient watering. The right
controller, properly scheduled, can result in significant
water savings and lower water bills.
How Does a Controller Work?
An automatic irrigation system is a collection of pipes,
tubing, valves, sprinkler heads, and circuitry used to
irrigate a landscape. Automatic valves (also called sta-
tions or zones), which control the flow of water to
different parts of the landscape, open and shut upon a
signal from the controller. For example, there may be
one valve that controls the water flow to some
grpundcover, another valve for some shrubs and another
valve for the lawn. Once programmed, the controller
determines when, how often, and how long each valve is
open. It controls how much water goes where and when
in your landscape based upon your instructions. The more
programming flexibility the controller has, the more
efficiently water can be applied to the landscape.
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Why Certain Controller Features are Important
The key to watering efficiently is to obtain a control-
ler that can handle diverse landscape and weather
situations and then to program it properly to meet
your plants' water needs. Let's imagine you have a front
yard with three valves that control the water flow to a
sloped lawn area, to several trees, and to a groundcover
area. You desire to water the lawn every third day for the
entire month in three short time intervals of five minutes
each and want a 30-minute break between watering to
avoid runoff from the slope. You also desire to water the
trees, which are on a drip system, once a month for two
hours. Next, you want to water the groundcover once a
week for 30 minutes. Finally, you don't want to water if
it is raining. To accomplish this, your controller would
need the following features: 1) three independent pro-
grams, 2) 120 minute station run times, 3) three start
times per program, 4) interval program capability to 30
days, and 5) rain shut-off device capability (the actual
rain shut-off device needs to be purchased separately).
Important Water Saving Features
The recommended minimum hardware features for a
controller when water efficiency is a priority include:
Hardware Features
• Three independent programs
• Station run times from one to 200 minutes
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• Three start times per program
• Odd/even, weekly and interval program capability
up to 30 days
• Water budgeting from 0-200%, in 10% increments,
by program
• 365 day calendar, adjusted for leap year
• Non-volatile memory or battery back-up
• "Off", "Auto"/and " Manual" operation modes
without disturbing programming
• Rain shut-off device capability
• Diagnostic circuitry to notify homeowner when
station is shorted or a power failure has occurred
The above features, discussed in more detail below, are
important because they give you the ability to properly
manage your landscape watering.
Multiple independent programs allow watering differ-
ent parts of the yard on different days. Station run times
determine the upper and lower limit on how long an area
can be watered. While watering times are usually in
minutes, a few controllers are capable of assigning run
times in seconds (for potted plants) and hours for drip
applications. Multiple start times allow for repeat
watering in the same area on the same day. Odd/even
weekly and interval program capability allows for
flexibility in deciding what days to water. For example, a
30-day calendar would allow watering a large tree once a
month. Water budgeting (also known as a percent
switch) allows for an increase or decrease in station run
times by a certain percent. For example, during a cool
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spell, you may want to decrease watering time by 10% for
all programs. This feature allows for the changing of all
station run times within a given program in one easy -
step. 365-day calendar allows for the tracking of the
number of days in each month throughout the year.
Non-volatile memory retains the set program in case of
a power failure. However, the set start watering times are
still affected. For example, a four-hour power failure
where the watering times are set to start at 6 a.m. would
result in 10 a.m. start. A battery back-up is recom-
mended to retain the 6 a.m. watering time. Controllers
with only volatile memories would both lose their set
program and have the watering start time affected. For
controllers with volatile memories, a battery back-up
would retain both the set program and the set watering
times. Rain shut-off device capability (and rain shut-
off device) is used to automatically override the call for
water during rain events. (The actual rain shut-off device
needs to be purchased separately since it is not included
with the controller.) Diagnostic circuitry to notify
homeowner when a station is shorted or a power failure
has occurred is useful so that the controller can be
checked for any changes or problems as soon as possible.
In addition to the above hardware, programming instruc-
tions, technical support phone numbers, and irrigation
scheduling information are important resource tools.
Check with your local water utility, irrigation supply
company or landscape professional for local watering
guidelines.
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Opliond Conlrdller features
Besides the above mentioned recommended controller
features, several desirable but optional features include
"pause times' and "soak cycles". The "pause time"
feature allows for some time to elapse before watering
different stations within a program. This feature allows
time for a control valve to completely close before the
next valve opens ensuring more uniform pressure and
thus better uniformity of coverage. For those on well
water, this feature may allow time for the level in the well
to recover before the next irrigation cycle. The "soak
cycle" allows for short, multiple watering cycles. This
feature can be used either before a normal irrigation cycle
to wet the soil to break the soil surface tension to reduce
runoff or for multiple, short watering of a given area.
Controller Warranty
Ask about the warranty on any controller you are consid-
ering. The length of a product warranty is often linked to
quality and many controller manufactures are offering
warranties in the 2-5 year range: the longer, the better.
Other Important Component of an Efficient Irrigation System
Besides obtaining an irrigation controller with the recom-
mended features, there are other irrigation components
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that should be used with irrigation systems to save addi-
tional water. Control valves control the flow of water to
different parts of the landscape and are used for the
separate watering of plants with different watering needs.
Check valves can be installed in sprinkler heads to
prevent water from draining out of the irrigation line
when the water is turned off and are most useful on sloped
landscapes. Rain shutoff devices can be wired to a
controller to shut off the system when it is raining.
Moisture sensors can be wired to control valves to
override the caU for water if they "sense" that enough
moisture is already present in the soil. Moisture sensors,
therefore, "monitor" the irrigation schedule for over
watering. Drip or bubbler irrigation can be used to
irrigate slowly and minimize or eliminate evaporation,
runoff and overspray. Finally, low precipitation spray,
stream, and sprinkler heads with matching precipita-
tion rates can dramatically improve efficiency.
It is important to note that automatic irrigation systems,
if not properly managed, can waste a lot of water. Always
be mindful that YOU are the "brains" behind your
irrigation system scheduling and YOU control the con-
troller.
The Importance of Proper Irrigation Scheduling
Plants require the most water during the summer and
little or no water in the winter. After July, plants need
less water each month, and by November, often little or
no irrigation is required until March or April. Then, plant
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water needs increase each month through July. The chart
below compares the typical month to month average
percentage changes in your landscape's water require-
ment to the July requirement. For example, the
landscape's water requirement in May is twice that of
April but only 60% of the July requirement. This chart
demonstrates the importance of regularly changing
your irrigation schedule. Note that by the end of
September, your landscape will need only about half
of the water it needed in July. Since this chart is based
upon the change by month in a plant's water need, local
precipitation will, of course, affect how much supplemen-
tal irrigation is needed. Check with your local water
agency or Cooperative Extension office for specific
monthly water requirements for your landscape.
Typical Monthly Percentage Comparison of Landscape Water.
Need Using July as Basis
3an feb Mar Apr May ]un ]ul Aug Sep Oct Nov Dec
0 0 5 30 : 60 90 100 90 60 30 5 ' 0
Other Water Saving Landscape Practices
Besides proper irrigation system design and scheduling,
water use efficiency in the landscape can also be in-
creased through appropriate use of plant material, soil
preparation, and proper horticultural practices (mainte-
nance).
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Extensive use of plants suited for the climate of the
region should be considered for your landscape. Plants
should be grouped, as much as practical, according to
their water requirements. Proper horticultural practices
that include regular pruning, weeding, lawn aerating
and dethatching, and the use of mulches and fertilizers
should be followed.
For more detailed information regarding water saving
opportunities in the landscape contact your local oppor-
tunities in the landscape contact your local water agency,
irrigations supply store, or landscape professional.
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SAMPLE WATER SCHEDULE
The chart below shows a sample watering schedule. You
can increase or decrease the amount of water applied to the
landscape by changing either the number of start times per
day, the number, of minutes per day, or the number of
watering days per week. Note in this example the watering
times stay the same but the number of watering days per
week, change during the year. Also, note no watering is
shown for the winter months. To determine the appropri-
ate watering schedules for your area, contact your local
water agency or landscape professional. Keep your sched-
ule in your controller for easy references.
Sample Wafer Schedule
Plan}
Type
lawn
groundcover
shrubs
trees
Sprinkler
Type
spray
spray
drip
drip
Starts
per day
2
2
1
2
Minutes
per day
7
7
30
30
Number of Watering Days per Week
fall and Spring Summer
2
.5
'.5
0
3
1
1
.5
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