Outdoor
Sprinkler system installation cost
An irrigation system is built out of zones, and the number of zones comes from how much water your house can deliver — not from how big the garden is. Two identical lawns on different water services need a different number of zones and cost different money, which is why every price per square foot you will read is a range. Start with a bucket.
Written and edited by Pablo Ruiz Quintero
Last reviewed 2026-09-21 · Nothing you type leaves your browser
Start with the water, not the lawn
The number of zones is what you pay for, and it comes from how much water your house can deliver — not from how big the garden is. Two identical lawns on different water services need a different number of zones and cost different money.
Run an outside tap wide open into a 5-gallon bucket and time it. It is the only measurement that matters and it takes thirty seconds.
That is 10 gpm, and 7.5 to design with.
A gauge on an outside tap with nothing running. Under 40 psi the head choice narrows a lot.
The garden
Leave the width blank if there is no back lawn.
The narrow way.
Zero if there is none.
The narrow way.
These get drip, not spray — water at the root, no evaporation and nothing on the fence.
The system
Multiple rotating streams on a spray body. A third of the flow of a spray for a wider throw, which means far more heads on a zone and fewer zones overall — often the cheapest system on a house with modest water pressure, and almost nobody offers it.
Simplest to lay out and to trench. Every head sits at the corner of a square whose side is the head's radius.
The forgiving one. It will take most precipitation rates without complaining and holds enough that twice a week is usually plenty.
Flexible black pipe, joined with barbed fittings and clamps. It survives a freeze that would split PVC, which is why the north uses it — and it can be pulled in with a vibratory plough instead of trenched.
The common residential answer. It has to sit at least twelve inches above the highest head, which on a sloping garden decides where it goes.
The mainline run, which is trenched like everything else.
Every foot of climb costs about half a psi at the nozzle.
Rock, roots or heavy clay roughly doubles the trenching, which is the biggest single labour line on the job.
The trenching is rentable and the plumbing is simple; the design is the part worth paying for, and it is the part above.
Used only to pick a regional labour rate. It stays in your browser.
2 zones, installed
$3,387
18 heads · 1,950 ft² · $144 a zone after the first
10 gpm is what decides this, not the lawn
Designing at 7.5 gpm — three quarters of what you measured — this garden needs 2 lawn zones. More water at the tap would mean fewer zones and a smaller bill for exactly the same garden, which is why no price per square foot can be right.
Will the pressure reach the nozzle?
Comfortable. Below its rated pressure a head does not simply throw shorter — the pattern breaks up and the coverage goes with it, so the margin here matters more than it looks. The friction figure is an estimate for a normal residential run, not a Hazen-Williams calculation on your actual pipe.
And how long to run it
Which nobody tells you after taking the money.
Back lawn — 3 × 3 heads
Every 20 ft, which is the head’s radius. The circles have to reach the next head.
Front lawn — 3 × 3 heads
Every 20 ft, which is the head’s radius. The circles have to reach the next head.
The same garden with each head type
Head choice changes the zone count, and the zone count moves the price far more than the heads themselves ever do.
| Head | Throw | Zones | Installed |
|---|---|---|---|
| Fixed spray | 15 ft | 5 | $3,602 |
| Gear-driven rotor · overshoots | 30 ft | 2 | $3,024 |
| Rotary nozzle · yours | 20 ft | 2 | $3,387 |
A rotary nozzle uses a third of the flow of a fixed spray for a wider throw, so far more heads fit on one zone. On a house with modest water it is frequently the cheapest system there is, and almost nobody offers it. A head marked overshoots throws further than the narrowest part of your garden is wide — it will be cheaper on this table and it will water the fence, so read that row as unavailable rather than as a bargain.
What goes in the ground
- Rotary nozzle heads
20 ft throw at 40 psi, spaced every 20 ft — which is the radius, not the diameter.18 - Zone valves and boxes
One valve per zone in a manifold. The valve is the cheap part — what a zone really costs is the wire to it and the trench it sits in.2 - Polyethylene pipe
396 ft of laterals plus 100 ft of mainline from the meter.496 ft - Direct-burial wire
Controller to manifold, with a spare conductor. Running a new wire later means digging the route again.120 ft - Pressure vacuum breaker
The common residential answer. It has to sit at least twelve inches above the highest head, which on a sloping garden decides where it goes.$320
What it costs
National average. 2 zones, 18 heads, 496 ft of pipe trenched in, valves, wire, controller, backflow preventer and the permit. Not included: repairing the lawn where the trench ran, and any tap or meter upgrade if the flow turns out not to be there.
$1,694 a zone on average, but that average is misleading at 2 zones: $1,253 of this is the backflow preventer, the controller, the mainline and the permit, and none of it scales with the zone count. Adding one more zone costs about $144, which is the number to hold against a quote. Trenching alone is $1,389. And every year after: about $105 to blow the lines out before the first hard freeze. New turf goes down after the irrigation, never before.
Worth knowing
- 10 gallons a minute at the tap is 7.5 to design with — nobody designs to the whole of it, because the flow at a tap is not the flow at the end of two hundred feet of pipe and somebody still has to be able to flush a lavatory while it runs. That 7.5 is what sets the number of zones, and the number of zones is what you are actually paying for.
- Heads go every 20 ft, which is the radius and not the diameter. A sprinkler does not water its circle evenly — it throws far more water close to itself than at the edge — so the edge of one has to reach the next head. Spacing them at the diameter is the commonest reason a new system leaves dry rings, and the heads get blamed for it.
- About 68 minutes a zone, 2 times a week in season, to put down the 1.25 in your loam soil wants. Deep and infrequent beats little and often — it pulls the roots down, and a lawn with deep roots survives a week you forget about it.
- A backflow preventer is not optional and it is not a detail: it is what stops fertiliser and whatever the dog left on the lawn being siphoned back into the drinking water when the main loses pressure. The common residential answer. It has to sit at least twelve inches above the highest head, which on a sloping garden decides where it goes. Budget $320 for the device and expect an inspection.
- And the recurring cost nobody quotes: Blowing the lines out with compressed air before the first hard freeze, every year, wherever the ground freezes. Skipping it once splits pipe underground and cracks valve bodies, and the repair costs more than a decade of blowouts. About $105 a year wherever the ground freezes.
On this page — 6 sections
The water decides the zones, and the zones are the price
The short version
- Zones come from your flow, not your lawn size. Two identical gardens on different water services need different numbers of zones and cost different money.
- Design to 75 per cent of measured flow, never the whole of it.
- Heads go at the radius, not the diameter. It looks like huge overlap and it is the minimum.
- About $600 to $1,200 a zone installed, and trenching is the largest single line in it.
Every irrigation price you will find online is quoted per square foot, and every one of them is a wide range — usually a factor of two or three. The range is not caution. It is the shape of a number that has been calculated from the wrong input.
An irrigation system is built out of zones. A zone is a valve, a wire run back to the controller, a place in a manifold box, and a set of heads that run together. That is the unit that gets bought, installed and paid for.
And the number of zones does not come from the lawn. It comes from the water.
Take an ordinary garden: 1,200 square feet at the back, 750 at the front. With fixed spray heads that is around 37 gallons a minute of demand. On a house delivering 10 gallons a minute you design to 7.5, and it needs five zones. On a house delivering 16 you design to 12, and the same garden needs four. Same lawn, same heads, a different bill.
Which is also why the single most useful thing a contractor can do on a first visit is put a bucket under your tap — and why one who quotes a price per square foot without doing it is guessing.
75%
Of measured flow
What you design to, never all of it
96.3
The precipitation constant
GPM and area into inches an hour
$2.8/ft
Trenching
The biggest single labour line
$105
Every year, forever
Blowing the lines out before the freeze
Irrigation Association, Landscape Irrigation Best Management Practices — system design and distribution uniformity · checked 2026-09-21
Head-to-head: the spacing is the radius
This is the design rule that gets broken most often, and it is broken because the correct answer looks wasteful.
A sprinkler head with a 15 foot radius goes every 15 feet. Not every 30. Each head throws all the way to the next one, so the circles overlap by their entire radius, and every square foot of lawn is covered by at least two heads and often four.
The reason is that a sprinkler does not water its circle evenly. Nothing does. The distribution is heavy near the head and falls away towards the edge of the throw, so the outer ring of each circle is putting down a fraction of what the middle is. On its own it would leave a lawn striped. What makes it even is the next head’s heavy middle landing on this head’s thin edge.
Space them so the circles merely touch — which is what most people do, because it looks like complete coverage on paper — and you get a dry ring at the meeting point of every four heads. The grass browns in a repeating diamond pattern, and the heads get blamed.
| Head-to-head, at the radius | Circles touching, at the diameter | |
|---|---|---|
| Spacing for a 15 ft head | 15 ft | 30 ft |
| Heads on a 40 × 30 lawn | Around a dozen | Around four |
| Looks like | Absurd overlap | Sensible coverage |
| Actually gives | Even coverage | A dry diamond between every four |
| Cost | More heads, more zones | Cheaper, and it does not work |
| What happens next | Nothing | Brown patches, blamed on the nozzles |
Three kinds of head, and the one nobody offers you
Head choice looks like a detail and it is the biggest lever on the price, because it changes the zone count — and the zone count is the cost.
| Head | Throw | Flow | Rate | What it is |
|---|---|---|---|---|
| Fixed spray | 15 ft | 3.7 gpm | 1.6 in/hr | The cheapest head and the thirstiest. It puts down about an inch and a half an hour, which is faster than most soil can take it — so short run times, and on clay it runs off before it soaks in. |
| Gear-driven rotor | 30 ft | 3 gpm | 0.45 in/hr | Throws twice as far as a spray for the same flow, so it covers four times the ground per head. Slow and gentle enough for clay, and it needs real pressure — below about 40 psi at the head the stream falls apart. |
| Rotary nozzle | 20 ft | 1.4 gpm | 0.6 in/hr | Multiple rotating streams on a spray body. A third of the flow of a spray for a wider throw, which means far more heads on a zone and fewer zones overall — often the cheapest system on a house with modest water pressure, and almost nobody offers it. |
Look at the middle two columns together, because that is where the argument is. A fixed spray covers a 15 foot circle on 3.7 gallons a minute. A rotary nozzle covers a 20 foot circle — nearly twice the ground — on 1.4. That is roughly five times the area per gallon.
Five times the area per gallon means five times as many heads fit on one zone, which means a fraction of the zones, which means a fraction of the valves, the wire runs and the manifold work. On a house with modest water pressure it is frequently the cheapest complete system available, and it waters more gently into the bargain.
It is offered rarely. Partly because it is a newer product than the spray head and the trade is conservative, and partly for the obvious reason: fewer zones is a smaller invoice. It is worth asking for by name.
MaterialsEstimator, Sprinkler nozzle performance survey — radius, flow and precipitation rate · checked 2026-09-21
What it costs, and the four things never in the quote
Between about $600 and $1,200 a zone installed covers most residential work. Within that, the split is not what people expect: the heads are almost a rounding error and the trench is the job.
Ask whether these are in the price, because they usually are not
- The backflow preventer — $320 for a vacuum breaker, $720 for a reduced pressure device, and which one you are allowed is set by the health department rather than by preference.
- The permit and the inspection, which irrigation connections need in most jurisdictions.
- Repairing the lawn where the trench ran. A vibratory plough barely marks it; a trencher leaves a scar that wants seed and topsoil.
- Winterisation, about $105 every year forever wherever the ground freezes — and the first one is usually the same autumn.
- A spare wire conductor buried with the others. It costs almost nothing now and it is the difference between a cheap repair and an expensive one later.
- A rain sensor or a weather-based controller, which several water utilities rebate in full.
- Head-to-head spacing rather than something looser — ask what spacing they are designing to, in feet, and compare it against the head radius.
- Which head type, and whether rotary nozzles were considered. The answer tells you how the zone count was arrived at.
One more that is worth raising before anybody digs: what happens if the flow is not there. Occasionally a bucket test comes back at six or seven gallons a minute, and the honest answers are a larger service line from the meter, a separate irrigation meter where the utility offers one, or a design built entirely around low-flow heads. All three are cheaper to decide on before the trencher arrives than after.
Sprinkler repair costs, and which ones are a twenty dollar part
Most sprinkler repairs are a cheap part and a call-out fee, and several of the commonest are not repairs at all. Worth knowing which is which before the van arrives.
| Symptom | Part | Fitted | Yourself | Usually means |
|---|---|---|---|---|
| Nozzle blocked or worn | $4 | $55 | yes | Grit from the main, usually after the water company has worked on the street. Unscrew, rinse the filter under the nozzle, refit — it is the repair most often sold as a new head. |
| Head cracked or snapped off | $9 | $75 | yes | A mower, a car or a frost. The head unscrews from a flexible riser below ground; the only real skill is not letting soil into the pipe. |
| Head sunk below the grass | $3 | $60 | yes | Soil settles around the head over a few seasons and the spray hits the grass in front of it. Dig, pack underneath, reset flush. No parts at all in most cases. |
| Zone will not turn on | $18 | $125 | maybe | Usually the solenoid on the valve rather than the valve itself — it unscrews from the top and it is an eighteen dollar part. Test it by turning the valve on manually with the bleed screw. |
| Zone will not turn off | $34 | $205 | maybe | Grit under the diaphragm holding the valve open. A rebuild kit is a fraction of a new valve and the diaphragm is four screws, though getting at a valve in a wet box is the unpleasant part. |
| Wet patch, one zone | $16 | $175 | maybe | A split lateral, usually where something was driven over or where a root has grown against it. Finding it is the work; the coupling itself is a few dollars. |
| Wet patch all the time | $30 | $340 | no | The mainline is under pressure whether the system is running or not, so a leak there never stops. It is also the one that shows up on the water bill before it shows up on the lawn. |
| One zone dead, valve is fine | $14 | $260 | no | A broken or corroded wire somewhere along the route, which has to be traced with a locator. It is the repair that costs real money, and it is the reason for burying a spare conductor. |
| Several things wrong in spring | $130 | $520 | no | Water left in the lines over a hard winter. Split pipe, cracked valve bodies and burst backflow devices, all at once — which is what a blowout costs a hundred dollars a year to avoid. |
The repair that genuinely costs money is a wire fault: around $260, because there is no shortcut to tracing a buried cable and it usually ends in digging. It is the entire argument for burying a spare conductor when the system goes in, which costs almost nothing at the time.
And the expensive one that is entirely avoidable is a system that was not blown out before a hard freeze. Water expands when it turns to ice and it does not care what it is inside — split laterals, cracked valve bodies and a burst backflow device, all found at once in spring. Blowing the lines out with compressed air before the first hard freeze, every year, wherever the ground freezes. Skipping it once splits pipe underground and cracks valve bodies, and the repair costs more than a decade of blowouts.
What goes wrong
01Pricing the job by the square foot
The unit that gets built and paid for is the zone, and the number of zones comes from your water supply. Two identical gardens on different services need different numbers of zones and cost different money.
Instead — Measure the flow with a bucket first, work out the zones from it, and compare quotes per zone. Anybody quoting per square foot without measuring your flow is guessing.
02Spacing heads at the diameter
A sprinkler throws far more water close to itself than at the edge of its circle, so the thin outer ring has to be topped up by the next head. Circles that merely touch leave a dry diamond between every four heads.
Instead — Space at the radius — head-to-head. A 15 ft head goes every 15 ft. It looks like enormous overlap and it is the minimum.
03Mixing sprays and rotors on one zone
Their precipitation rates differ by about four to one. There is no run time that satisfies both — one half of the lawn floods while the other burns.
Instead — One head type per zone, always. And beds get their own drip zones, because drip runs for hours where a lawn zone runs for minutes.
04Designing to all of the available flow
The flow at a tap is not the flow at the end of two hundred feet of pipe with a dozen fittings, and the house still has to work while the garden is being watered.
Instead — Design to about 75 per cent of what the bucket test gives. The margin is the difference between a system that works in August and one that limps.
05Putting rotors in a narrow garden
A 30 ft throw in a 25 ft garden waters the fence and next door, and every gallon is metered.
Instead — Match the throw to the narrowest part of the area. Below about thirty feet of width, use rotary nozzles or sprays and accept more heads.
06Ignoring what the soil can absorb
Clay soil takes about 0.2 of an inch an hour and a fixed spray delivers 1.6. The surplus runs down the drive, so you are paying for water that never reaches a root.
Instead — Turn on cycle and soak — several short bursts with an hour between them. Every modern controller does it and almost nobody uses it.
07Leaving the backflow preventer out of the comparison
It is legally required, it is a real cost — $320 to $720 plus fitting — and it is the item most often missing from the cheaper of two quotes.
Instead — Ask which device is being fitted and whether the permit and inspection are included. The answer often explains the whole difference between two prices.
08Skipping the winter blowout to save a hundred dollars
Water left in the lines through a hard freeze splits pipe underground, cracks valve bodies and bursts the backflow device — and all of it is found at once, in spring, at several thousand dollars.
Instead — Book it every autumn where the ground freezes. It is about $105 and it is the cheapest insurance on the property.
- 01Measure the flow firstOutside tap wide open, nothing else running, five-gallon bucket, time it. Sixty divided by the seconds, times five, is your gallons per minute. This single number does more to set the price than anything about the garden.
- 02Measure the pressureA gauge on the same tap with nothing running. Under 40 psi the head choice narrows sharply, and it is better to find that out now.
- 03Design to three quarters of the flowNever the whole of it. The flow at a tap is not the flow at the end of two hundred feet of pipe, and somebody still has to be able to use the house while it runs.
- 04Choose the head for the spaceThe throw has to fit the narrowest part of the lawn. A 30 ft rotor in a 25 ft wide garden waters the neighbour, and you pay for every gallon of it.
- 05Space at the radius, not the diameterHead-to-head, every time. The edge of each circle has to reach the next head, because that edge is the thinnest part of the pattern.
- 06Count the zonesTotal flow for the heads, divided by the design flow. That number times roughly seven hundred dollars is most of your answer.
- 07Add the things that are never quotedThe backflow preventer, the permit, the lawn repair where the trench ran, and about a hundred dollars a year forever to blow the lines out.
Order matters and it only works one way: the irrigation goes in first, then the turf over it. Laying sod and then trenching through it is paying twice for the same lawn.
If new turf is going down too- Zone
- A group of heads that run together off one valve. It is the unit an irrigation system is actually built and priced in, and the number of them comes from your water supply rather than from the size of the garden.
- GPM
- Gallons per minute — how much water your house can deliver. Measure it by timing a five-gallon bucket at an outside tap, and design to about three quarters of what you get.
- Static pressure
- The pressure with nothing running, measured with a gauge on an outside tap. It is what everything else is subtracted from: the backflow preventer, the rise in the ground, the pipe, the fittings.
- Head-to-head
- Spacing heads so that each one throws all the way to the next. It sounds excessive and it is the minimum, because a sprinkler puts down far more water close to itself than at the edge of its circle.
- Precipitation rate
- How fast a zone puts water down, in inches an hour. It comes out of the flow and the area, and it is what run times are calculated from — not from a guess.
- Matched precipitation
- Every head on a zone putting water down at the same rate. It is why rotors and sprays can never share a zone: their rates differ by about four to one, so one half of the lawn drowns while the other burns.
- Cycle and soak
- Splitting a zone's run into shorter bursts with time between them, so water can soak in rather than run off. Every modern controller does it and almost nobody turns it on.
- Backflow preventer
- The device that stops garden water being siphoned back into the drinking supply when the main loses pressure. It is legally required, it costs real money, and it is missing from most quoted prices.
- Mainline
- The pipe from the meter to the valve manifold, under pressure all the time. A leak in it never stops, which is why it shows up on the water bill before it shows up on the lawn.
- Lateral
- The pipe from a valve out to the heads on that zone, under pressure only when the zone runs. A leak here shows as a wet patch that appears while one particular zone is on.
- Blowout
- Clearing the lines with compressed air before winter. It costs about a hundred dollars a year where the ground freezes, and skipping it once costs several thousand.
- Rotary nozzle
- Multiple slow rotating streams on a spray body. About a third of the flow of a fixed spray for a wider throw, which puts far more heads on a zone — and therefore fewer zones on the invoice.
Common questions
- How much does it cost to install a sprinkler system?
- Roughly $600 to $1,200 a zone installed on a typical four-to-eight zone system, so most residential jobs land between about $3,000 and $7,000. Two warnings about that per-zone figure. It is an average, and on a small two or three zone system it comes out much higher, because the backflow preventer, the controller, the mainline from the meter and the permit cost the same whatever the zone count — adding a zone to an existing design is only a few hundred. And the zone count itself comes from how much water your house can deliver, not from how big the lawn is.
- What decides how many zones I need?
- Your flow, almost entirely. Measure it with a bucket, take three quarters of it as the design figure, and divide the total flow of all your heads by that. A house with 8 gallons a minute needs roughly twice the zones of one with 16 for exactly the same garden — and pays roughly twice as much, because zones are the cost. No price per square foot can be right about this, which is why every one you see is a range.
- How far apart should sprinkler heads be?
- At the radius, not the diameter — a 15 ft spray head goes every 15 ft. It looks like enormous overlap and it is the minimum. A sprinkler does not water its circle evenly: it throws far more water close to itself than at the outer edge, so that thin outer ring has to be topped up by the next head. Space them so the circles just touch and you get a dry ring between every four heads, and the heads get blamed for it.
- How do I measure my water flow for a sprinkler system?
- Five-gallon bucket under an outside tap, tap wide open, nothing else running in the house, and time how long it takes to fill. Thirty seconds is 10 gallons a minute; twenty seconds is 15. Do it at the tap closest to where the system will connect, and do it at the time of day you would normally water, because pressure drops in the evening when the whole street is using it.
- Can I mix spray heads and rotors on the same zone?
- No, and it is the mistake that ruins otherwise decent systems. A fixed spray puts down about 1.6 inches an hour and a rotor about 0.45 — four times the difference. Run them together for long enough to satisfy the rotors and the spray area floods; run them for the sprays and the rotor area burns. One head type per zone, always.
- What is a rotary nozzle and why has nobody offered me one?
- Multiple slow rotating streams on an ordinary spray body. It throws 20 ft on about 1.4 gallons a minute, against 3.7 for a fixed spray covering less ground — so far more heads fit on one zone, and the zone count drops. On a house with modest water it is frequently the cheapest complete system available. It gets offered rarely because it is a newer product and because fewer zones is a smaller invoice.
- Do I need a backflow preventer, and what does it cost?
- Yes, everywhere, and it is not a detail to negotiate. It is what stops fertiliser, weedkiller and whatever the dog left on the lawn being siphoned back into the drinking water when the main loses pressure. A pressure vacuum breaker is about $320 and has to sit at least twelve inches above the highest head; a reduced pressure zone device is about $720 and needs annual testing. Which one you are allowed depends on your local health department.
- How much does it cost to replace a sprinkler head?
- About $75 fitted, of which the head itself is $9 — you are paying for somebody to come out. Before you call, check whether it is actually the head: a blocked nozzle is a $4 part that rinses clean under a tap, and a head that has simply sunk below the grass needs no parts at all. Both get sold as replacements.
- How much does sprinkler repair cost?
- Most repairs are a part worth under twenty dollars plus a call-out: a head is about $75 fitted, a solenoid about $125, a stuck valve about $205. The one that costs real money is a wire fault — around $260, because it has to be traced along the whole route. And a system that was not blown out before a hard winter can come back in spring with several thousand dollars of split pipe and cracked valve bodies.
- How long should I run each zone?
- It comes out of the precipitation rate rather than a rule of thumb. Work out how fast the zone puts water down — flow, area, and the constant 96.3 — then divide the weekly requirement by that. Fixed sprays at about 1.6 inches an hour need short runs; rotors at 0.45 need three or four times as long for the same water. Deep and infrequent beats little and often, because it pulls the roots down.
- Why does water run off my lawn when the sprinklers are on?
- Because the system puts water down faster than the soil can take it. Clay soil absorbs about 0.2 of an inch an hour and a fixed spray delivers 1.6 — seven times faster — so the surplus goes down the drive. The answer is not shorter watering overall but cycle and soak: split the run into several short bursts with an hour between them. Every modern controller can do it and almost nobody turns it on.
- Can I install a sprinkler system myself?
- The physical work is very doable — the trencher is rentable, the pipe is glued or clamped, and the wiring is low voltage. What is worth paying for is the part above: the flow measurement, the head choice and the zoning. A system designed wrong is not fixable by working harder at installing it, and the commonest DIY failure is not bad pipework but heads spaced at the diameter.
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About the author
Pablo Ruiz Quintero — Editor
Editor of MaterialsEstimator. Decides which documents count as a source, what every default value is, and where the line sits between what the reader parses and what the engines compute.
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