Irrigation Systems
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Irrigation System Installation, Use and Maintenance
After you have installed or contracted to have installed your new Landscape and Lawn, you certainly don't want it
to die simply for not having enough water. You can drag hoses around and keep it watered if you have the time
and energy, but for a lot of us we simply do not have the time to be watering by hand. An automatic sprinkler
system will actually use less water than you will if trying to water by hand. This seems wrong, but it's been
proven that most of us will put the sprinklers out, and then forget to move them or turn them off and water it too
much. By watering by hand and letting the sprinkler water too much you let the water run off into the street or
down the ditch and waste water, lot's of it. An automatic sprinkler system will put down just the right amount of
water and not waste it, so you will use less this way, and waste less. A huge benefit of having an automatic
watering system is that when you seed your lawn you can get grass to germinate very fast with regular
waterings (three times a day) and get your lawn started faster than watering by hand or no watering at all.
Annual Flowers that are tender like Impatiens will benefit by having a splash of water twice a day during hot dry
periods. So you can have a much nicer landscape with lot's of color with an automatic sprinkler system than
without it. It is a large expense putting a system in, even if doing it yourself the pipe, heads, wire, valves, fittings,
electric wire, and assorted parts and supplies you will need really add up. But however much you spend on
improving your home and landscape will add to the value of your home.
Lets start with how you should water if you already have a system, or if your going to try to water by hand.
Watering is divided into two types of watering, establishment and maintenance. For newly seeded or sodded
lawns and newly planted landscapes we are talking about establishment. For lawns you need to water just as
soon as the lawn is installed. Don't wait for it to rain. If you seed today, start watering today and water the
seeded or sodded area long enough that water will build up and soak in. You really want to get it soaking wet
the first time. After that you need to water enough to keep the soil moist, not standing in water but moist. Stick
your finger in the ground if you have to, but be sure you have moisture down about 1". It may take watering 2 or 3
times a day to keep it moist, or once every other day. It will depend on lot's of things, how hot is it, is the wind
blowing, do you have shade, what time of year is it, etc. Use a little common sense and apply water when it is
needed and you will do fine. After the grass has gotten tall enough that it needs mowing, you can turn the water
off for a day or so to allow it to dry out. Be sure the grass is dry before putting your mower on it so you don't do
damage to it. After you mow the new grass, just keep an eye on the moisture content of the soil, if it dries out,
your grass will die because it will only have a root system a couple inches deep, so if the soil dries out deeper
than the root system, your lawn will die. It will take a month or so of watering to get the lawn so it doesn't need
to be kept wet on the surface. At some point you will need to start watering less frequently and for longer
periods of time. For establishment you will only be watering for a short time in each section, maybe 10 minutes
or so, however long it takes to get the soil damp, after the lawn is established you will move to watering only
once or twice a week for long periods in each section of the lawn. This may take 30 minutes or even an hour, it
just depends on how much water your sprinkler will put out and how fast. Most lawns will need at least one
inch of water per week. If you have an extreme drought like we have had here in Paris, TN. then you may need to
water longer.
Establishment watering for landscapes is much the same as it is for the lawn, you need to keep the plants
moist during the growing in phase but not soaking. We have customers very often that will kill their plants with
too much water. If you have a plant that is turning yellow, grab it and try to pull it up with your hands, if it slides
right up out of the hole and makes a suction sound, like it's sitting in water, you have watered too much.
Landscape plants won't need as much watering as your lawn. If you water your plants deeply twice a week after
they have been planted that may be enough. Again use a little common sense, check your plants during hot dry
weather and see if they need water. Some plants will wilt when they are beginning to stress from lack of
watering. You can pull back the mulch from around your plants and see if they are moist, or if you are killing
them with too much water. The weather conditions will affect your landscape just like your lawn. If it is hot, dry
and windy, you will need to water more than if it is overcast, raining and in the fall or spring. For new
landscapes you will need to watch closely the watering during the first month, and the entire summer if you
plant your landscape during late spring or summer. Landscape plants are like grass in that they will have a
shallow root system right after you plant them, then as their root system grows deeper, they will need less
water. So your watering habits will need to follow what your landscape plants tell you they want. Another thing
to try to do is to keep the water off the leaves as much as possible, this isn't a huge thing, but if your watering
with a hose and hand sprayer, water the base of the plant not the leaves. You can water the leaves to the point
of being wet, but that's not going to put enough water into the soil for the plant to pull up through it's system.
Soak the mulch down good and that will be enough.
Winterizing When the temps in your area start to drop below freezing, you will need to winterize your system.
This is pretty easy most of the time. There will be a schrader valve on the system some where that you can
hook an air compressor up to the system. This will look just like a valve stem on a car tire. Usually it will be in a
valve box where you can have easy access to it. Or it may be installed in a basement or crawl space. If you cant
find it call your contractor who put the irrigation system in for you and ask where it is. If all else fails you can
install one. It is nothing more than a T, a reducing bushing in the side of the T reduced down to the 1/8" threads
that the schrader valve takes. The valve is screwed into the T, the T is installed inline in the system somewhere
that you can get easy access to it with your air hose off your air compressor. If you are installing it, remember to
put it close enough to the house to have access to electric power for your air compressor.
This is how we do it, pressure up the sprinkler system to about 40# of air. This of course is after you have
turned the water supply to the irrigation system off. Pressure up the system, then push the button on your
irrigation clock, or timer, that will open the first valve. Some timers have a "test" function that will open each
valve for a short period of time you set, usually 1 or 2 minutes. This cycle is handy since you can set the clock to
do a "test" of all valves, and stay with the compressor and charge the system with air. Each time a valve on the
irrigation system opens up, it will blow water out of the lines and the sprinkler heads will jump up and down as
first the water expels, then the air will cause the jumping. Go through each zone at least 2 times, and your done.
A lot of systems have what are called "automatic drain back valves" on them. These are supposed to let water
drain out of the system each time it shuts off making it freeze proof after each run. I don't like to take chances
on these, I don't even use them. In my area we are going to blow out most systems each year so they aren't
needed. Farther south they would be plenty safe, here and farther north I don't trust them. After you winterize the
irrigations system put a note inside the clock face telling anyone who might open the clock door that "This
system was winterized on XX/XX/XX and leave water supply turned off. This will prevent someone from trying to
turn the system on after it has been drained. Mainly on multi-family buildings is where this would be a problem,
on your own personal home where only you are there you will know what has and hasn't been done.
Sprinkler systems are installed based on "zones". A zone is an area that you will water at one time. Let's say
you have a typical city lot, a front lawn, side lawn and back lawn, landscaping in front and landscaping in back.
In this situation you would most likely water the front lawn by itself, the side lawn by itself and the back lawn by
itself, and then the two landscape sections by themselves. You have to break up the lawn and landscape into
sections because you can't water all of that area at once, it will take too much water pressure and volume and
your water meter won't supply that much. So we break the lawn and landscape up into areas or "zones" and
water each section at a time. Some of the areas we are talking about may need to be broken down into two or
more zones depending on how large they are. If you have a front lawn that is say, 150' X 75' you will have to
break it down into 2 or 3 zones in most cases.
If you are a homeowner and going to try to design and install a system yourself I would recommend getting a
book on Irrigation design and installation to prevent you from making a huge mistake that could cost you lot's of
money and time later. I know of one person who thought they would put a system in, after all it doesn't look that
hard, they have a well system that they ran the sprinkler system off of. There is nothing wrong with that, we do it
all the time. The problem came when the sprinkler system wasn't working like they thought it should, the heads
were just piddling a stream of water out, so they upped the pressure on their well. This fixed the piddling
sprinkler head problem, but it also put excess pressure on the plumbing in the house. One day while they were
gone on vacation, a pipe broke in the upstairs bathroom, flooding the house. Sheetrock, carpet, some walls all
had to be torn out and replaced. All because a pressure reducing valve wasn't installed where it needed to be.
Or, if the person would have understood the concept of water volume and capacity this could have been
prevented. You can find a good book on Irrigation, Sprinkler system design and installation here
When you have a well system, you will need to know how many gallons per minute (gpm) your
pump is producing and what size pump it is, 1/2 hp, 3/4 or 1 hp. Most pumps for typical well systems for a
house is 3/4 or 1 hp. and will produce 12 to 15 gpm. Once you know this you will be able to determine how
many sprinkler heads you can run at once to determine how many zones you will have to have. The sprinkler
heads you use will have a bearing on this too. Depending on the manufacturer, you can have .5 up to 12 gpm
coming out of each head. So if you only have a 12 gpm pump, you can only run 6 heads that are putting out 2
gpm, and if you do this you are leaving no water for the house to use for showers, washing clothes, etc. The
rule of thumb is to use no more than 60% of the available water volume for the irrigation system. That way there
will be water for your shower at 7 in the morning if the sprinkler system is running at the same time.
If you have a City water meter you can call the water dept and ask what size it is, they should be able to tell you
without looking at it, and they will know the gpm for that size meter. The average in our area of West Tn, in Paris,
Tn. is to have a 3/4 inch meter which will produce around 25 gpm. Another option is a seperate water meter for
your sprinkler system, this will be an additional tap charge from the City to install it for you, but then you don't
have to pay sewer charges on the water being used so in the long run you will save more than enough to cover
the cost of the additional water meter. Another benefit is that you can request a 1 inch meter or larger if you
need, to cover the size property you have, if you have a large property that is going to require several zones it will
be better to have a larger meter. Still, one more option is to have a pump taking water out of a pond or lake, if
you happen to be near one. In our area we have Kentucky Lake, and a lot of Lake homes. These always get
water from the lake. Its basically free water except for the electricity it takes to run the pump. The lake water also
has a bit of fertilizer value since it is full of organic debris and fish waste and such. These systems get a bit
complicated since there is a 220volt pump, 110 volt hook up for the irrigation timer, and 24 volts to power a
pump start relay box, so it would be best to call on a professional for this part. This can be a dangerous thing if
you don't know what your doing. Obviously, you can be killed by electricity if you don't know what your doing so
consider this warning our legal disclaimer that we do not encourage anyone doing this type of work if your not
qualified and if you do so, you do at your own risk, not ours. This page is simply meant for helpful tips and in no
way is an instruction manual for the project you may do.
Irigation System Design - After you determine what water source you are going to use, you can now start
determining where you will put sprinkler heads. You have to know the water source volume in gpm, and how
much pressure you can expect to know how far apart you can put sprinkler heads. Most manufacturers will
have a chart with their heads to tell you how far the head will throw water at a given pressure. All you have to do
now is measure off this increment in the lawn and put flags every 30 feet or so, (whatever the distance is that
the sprinkler head will throw) in a grid pattern all across the lawn. Nice even square lawns are easy, but when
you get into the odd shaped areas you will have to use some common sense. Don't put long throwing rotor
style sprinkler heads in an area where they will hit the house, spray out into the street, or cover a sidewalk. In
the small areas you will have to use the shorter throwing spray heads and space them accordingly. Each
manufacturer will have instructions with the heads to show patterns and spacing based on the pressure your
water system is giving you.
After you have covered the entire lawn with flags putting them where you will eventually place a sprinkler head,
you will add up all of the heads into categories.
1) how many lawn rotor heads
2) how many lawn spray heads
3 How many shrub and landscaping heads
With this information you can determine how to break the total number of heads up into "zones". Again, a zone
is a group of the same type of head all watering at the same time. Usually your going to have around 6 to 10 at
the most heads running at one time on the average home sprinkler system. Larger commercial systems with
a large water supply can run many more at one time, but that isn't the scope of this page. After you have the
heads added up into categories, now you will draw the property out on a piece of paper and start to figure out
which of the heads need to be hooked to the same zone. You will want to get the heads in general areas
hooked together to make plumbing easier. Like all the front lawn, or back lawn together. Or if it is going to be a
large project and the front lawn is going to take 18 heads or so, you will have two zones in the front. Then you
will want to hook all of the left side together, then all the right side together. This is easier to understand if you
have a sprinkler system design book to look at.
to die simply for not having enough water. You can drag hoses around and keep it watered if you have the time
and energy, but for a lot of us we simply do not have the time to be watering by hand. An automatic sprinkler
system will actually use less water than you will if trying to water by hand. This seems wrong, but it's been
proven that most of us will put the sprinklers out, and then forget to move them or turn them off and water it too
much. By watering by hand and letting the sprinkler water too much you let the water run off into the street or
down the ditch and waste water, lot's of it. An automatic sprinkler system will put down just the right amount of
water and not waste it, so you will use less this way, and waste less. A huge benefit of having an automatic
watering system is that when you seed your lawn you can get grass to germinate very fast with regular
waterings (three times a day) and get your lawn started faster than watering by hand or no watering at all.
Annual Flowers that are tender like Impatiens will benefit by having a splash of water twice a day during hot dry
periods. So you can have a much nicer landscape with lot's of color with an automatic sprinkler system than
without it. It is a large expense putting a system in, even if doing it yourself the pipe, heads, wire, valves, fittings,
electric wire, and assorted parts and supplies you will need really add up. But however much you spend on
improving your home and landscape will add to the value of your home.
Lets start with how you should water if you already have a system, or if your going to try to water by hand.
Watering is divided into two types of watering, establishment and maintenance. For newly seeded or sodded
lawns and newly planted landscapes we are talking about establishment. For lawns you need to water just as
soon as the lawn is installed. Don't wait for it to rain. If you seed today, start watering today and water the
seeded or sodded area long enough that water will build up and soak in. You really want to get it soaking wet
the first time. After that you need to water enough to keep the soil moist, not standing in water but moist. Stick
your finger in the ground if you have to, but be sure you have moisture down about 1". It may take watering 2 or 3
times a day to keep it moist, or once every other day. It will depend on lot's of things, how hot is it, is the wind
blowing, do you have shade, what time of year is it, etc. Use a little common sense and apply water when it is
needed and you will do fine. After the grass has gotten tall enough that it needs mowing, you can turn the water
off for a day or so to allow it to dry out. Be sure the grass is dry before putting your mower on it so you don't do
damage to it. After you mow the new grass, just keep an eye on the moisture content of the soil, if it dries out,
your grass will die because it will only have a root system a couple inches deep, so if the soil dries out deeper
than the root system, your lawn will die. It will take a month or so of watering to get the lawn so it doesn't need
to be kept wet on the surface. At some point you will need to start watering less frequently and for longer
periods of time. For establishment you will only be watering for a short time in each section, maybe 10 minutes
or so, however long it takes to get the soil damp, after the lawn is established you will move to watering only
once or twice a week for long periods in each section of the lawn. This may take 30 minutes or even an hour, it
just depends on how much water your sprinkler will put out and how fast. Most lawns will need at least one
inch of water per week. If you have an extreme drought like we have had here in Paris, TN. then you may need to
water longer.
Establishment watering for landscapes is much the same as it is for the lawn, you need to keep the plants
moist during the growing in phase but not soaking. We have customers very often that will kill their plants with
too much water. If you have a plant that is turning yellow, grab it and try to pull it up with your hands, if it slides
right up out of the hole and makes a suction sound, like it's sitting in water, you have watered too much.
Landscape plants won't need as much watering as your lawn. If you water your plants deeply twice a week after
they have been planted that may be enough. Again use a little common sense, check your plants during hot dry
weather and see if they need water. Some plants will wilt when they are beginning to stress from lack of
watering. You can pull back the mulch from around your plants and see if they are moist, or if you are killing
them with too much water. The weather conditions will affect your landscape just like your lawn. If it is hot, dry
and windy, you will need to water more than if it is overcast, raining and in the fall or spring. For new
landscapes you will need to watch closely the watering during the first month, and the entire summer if you
plant your landscape during late spring or summer. Landscape plants are like grass in that they will have a
shallow root system right after you plant them, then as their root system grows deeper, they will need less
water. So your watering habits will need to follow what your landscape plants tell you they want. Another thing
to try to do is to keep the water off the leaves as much as possible, this isn't a huge thing, but if your watering
with a hose and hand sprayer, water the base of the plant not the leaves. You can water the leaves to the point
of being wet, but that's not going to put enough water into the soil for the plant to pull up through it's system.
Soak the mulch down good and that will be enough.
Winterizing When the temps in your area start to drop below freezing, you will need to winterize your system.
This is pretty easy most of the time. There will be a schrader valve on the system some where that you can
hook an air compressor up to the system. This will look just like a valve stem on a car tire. Usually it will be in a
valve box where you can have easy access to it. Or it may be installed in a basement or crawl space. If you cant
find it call your contractor who put the irrigation system in for you and ask where it is. If all else fails you can
install one. It is nothing more than a T, a reducing bushing in the side of the T reduced down to the 1/8" threads
that the schrader valve takes. The valve is screwed into the T, the T is installed inline in the system somewhere
that you can get easy access to it with your air hose off your air compressor. If you are installing it, remember to
put it close enough to the house to have access to electric power for your air compressor.
This is how we do it, pressure up the sprinkler system to about 40# of air. This of course is after you have
turned the water supply to the irrigation system off. Pressure up the system, then push the button on your
irrigation clock, or timer, that will open the first valve. Some timers have a "test" function that will open each
valve for a short period of time you set, usually 1 or 2 minutes. This cycle is handy since you can set the clock to
do a "test" of all valves, and stay with the compressor and charge the system with air. Each time a valve on the
irrigation system opens up, it will blow water out of the lines and the sprinkler heads will jump up and down as
first the water expels, then the air will cause the jumping. Go through each zone at least 2 times, and your done.
A lot of systems have what are called "automatic drain back valves" on them. These are supposed to let water
drain out of the system each time it shuts off making it freeze proof after each run. I don't like to take chances
on these, I don't even use them. In my area we are going to blow out most systems each year so they aren't
needed. Farther south they would be plenty safe, here and farther north I don't trust them. After you winterize the
irrigations system put a note inside the clock face telling anyone who might open the clock door that "This
system was winterized on XX/XX/XX and leave water supply turned off. This will prevent someone from trying to
turn the system on after it has been drained. Mainly on multi-family buildings is where this would be a problem,
on your own personal home where only you are there you will know what has and hasn't been done.
Sprinkler systems are installed based on "zones". A zone is an area that you will water at one time. Let's say
you have a typical city lot, a front lawn, side lawn and back lawn, landscaping in front and landscaping in back.
In this situation you would most likely water the front lawn by itself, the side lawn by itself and the back lawn by
itself, and then the two landscape sections by themselves. You have to break up the lawn and landscape into
sections because you can't water all of that area at once, it will take too much water pressure and volume and
your water meter won't supply that much. So we break the lawn and landscape up into areas or "zones" and
water each section at a time. Some of the areas we are talking about may need to be broken down into two or
more zones depending on how large they are. If you have a front lawn that is say, 150' X 75' you will have to
break it down into 2 or 3 zones in most cases.
If you are a homeowner and going to try to design and install a system yourself I would recommend getting a
book on Irrigation design and installation to prevent you from making a huge mistake that could cost you lot's of
money and time later. I know of one person who thought they would put a system in, after all it doesn't look that
hard, they have a well system that they ran the sprinkler system off of. There is nothing wrong with that, we do it
all the time. The problem came when the sprinkler system wasn't working like they thought it should, the heads
were just piddling a stream of water out, so they upped the pressure on their well. This fixed the piddling
sprinkler head problem, but it also put excess pressure on the plumbing in the house. One day while they were
gone on vacation, a pipe broke in the upstairs bathroom, flooding the house. Sheetrock, carpet, some walls all
had to be torn out and replaced. All because a pressure reducing valve wasn't installed where it needed to be.
Or, if the person would have understood the concept of water volume and capacity this could have been
prevented. You can find a good book on Irrigation, Sprinkler system design and installation here
When you have a well system, you will need to know how many gallons per minute (gpm) your
pump is producing and what size pump it is, 1/2 hp, 3/4 or 1 hp. Most pumps for typical well systems for a
house is 3/4 or 1 hp. and will produce 12 to 15 gpm. Once you know this you will be able to determine how
many sprinkler heads you can run at once to determine how many zones you will have to have. The sprinkler
heads you use will have a bearing on this too. Depending on the manufacturer, you can have .5 up to 12 gpm
coming out of each head. So if you only have a 12 gpm pump, you can only run 6 heads that are putting out 2
gpm, and if you do this you are leaving no water for the house to use for showers, washing clothes, etc. The
rule of thumb is to use no more than 60% of the available water volume for the irrigation system. That way there
will be water for your shower at 7 in the morning if the sprinkler system is running at the same time.
If you have a City water meter you can call the water dept and ask what size it is, they should be able to tell you
without looking at it, and they will know the gpm for that size meter. The average in our area of West Tn, in Paris,
Tn. is to have a 3/4 inch meter which will produce around 25 gpm. Another option is a seperate water meter for
your sprinkler system, this will be an additional tap charge from the City to install it for you, but then you don't
have to pay sewer charges on the water being used so in the long run you will save more than enough to cover
the cost of the additional water meter. Another benefit is that you can request a 1 inch meter or larger if you
need, to cover the size property you have, if you have a large property that is going to require several zones it will
be better to have a larger meter. Still, one more option is to have a pump taking water out of a pond or lake, if
you happen to be near one. In our area we have Kentucky Lake, and a lot of Lake homes. These always get
water from the lake. Its basically free water except for the electricity it takes to run the pump. The lake water also
has a bit of fertilizer value since it is full of organic debris and fish waste and such. These systems get a bit
complicated since there is a 220volt pump, 110 volt hook up for the irrigation timer, and 24 volts to power a
pump start relay box, so it would be best to call on a professional for this part. This can be a dangerous thing if
you don't know what your doing. Obviously, you can be killed by electricity if you don't know what your doing so
consider this warning our legal disclaimer that we do not encourage anyone doing this type of work if your not
qualified and if you do so, you do at your own risk, not ours. This page is simply meant for helpful tips and in no
way is an instruction manual for the project you may do.
Irigation System Design - After you determine what water source you are going to use, you can now start
determining where you will put sprinkler heads. You have to know the water source volume in gpm, and how
much pressure you can expect to know how far apart you can put sprinkler heads. Most manufacturers will
have a chart with their heads to tell you how far the head will throw water at a given pressure. All you have to do
now is measure off this increment in the lawn and put flags every 30 feet or so, (whatever the distance is that
the sprinkler head will throw) in a grid pattern all across the lawn. Nice even square lawns are easy, but when
you get into the odd shaped areas you will have to use some common sense. Don't put long throwing rotor
style sprinkler heads in an area where they will hit the house, spray out into the street, or cover a sidewalk. In
the small areas you will have to use the shorter throwing spray heads and space them accordingly. Each
manufacturer will have instructions with the heads to show patterns and spacing based on the pressure your
water system is giving you.
After you have covered the entire lawn with flags putting them where you will eventually place a sprinkler head,
you will add up all of the heads into categories.
1) how many lawn rotor heads
2) how many lawn spray heads
3 How many shrub and landscaping heads
With this information you can determine how to break the total number of heads up into "zones". Again, a zone
is a group of the same type of head all watering at the same time. Usually your going to have around 6 to 10 at
the most heads running at one time on the average home sprinkler system. Larger commercial systems with
a large water supply can run many more at one time, but that isn't the scope of this page. After you have the
heads added up into categories, now you will draw the property out on a piece of paper and start to figure out
which of the heads need to be hooked to the same zone. You will want to get the heads in general areas
hooked together to make plumbing easier. Like all the front lawn, or back lawn together. Or if it is going to be a
large project and the front lawn is going to take 18 heads or so, you will have two zones in the front. Then you
will want to hook all of the left side together, then all the right side together. This is easier to understand if you
have a sprinkler system design book to look at.
We are currently adding information to this page
periodically, Check back or e-mail us if you have a
specific question.
periodically, Check back or e-mail us if you have a
specific question.
