Sprinkler system installation runs in a set order: utility locates through Ontario One Call, a design that splits the yard into zones, a connection to your home’s water supply through a backflow preventer, trenching and pipe, heads set at grade, the controller and its sensors, then a pressure and coverage test before the lawn is repaired. Spring and late summer are the kindest windows for the lawn, because turf over the trench lines knits back fastest in cool, moist weather.
If you’re weighing a system for a property in Caledon, King City, Nobleton, Mono or New Tecumseth, here’s what actually happens on the day of a sprinkler system installation, the two steps you can’t skip in Ontario, how deep the lines go, and when to book so the yard looks untouched by the time you’re using it. Irrigation systems are one of the services in our residential lawn care program, so we’ll also share how the work is sequenced when a system is part of a bigger build.
Is an in-ground sprinkler system worth it for your property?
For a large lawn or a property with a lot of planting, an in-ground system is usually the easier way to water well, and it’s still an uncommon choice, which surprises people. Statistics Canada’s Households and the Environment Survey found that in 2023 only 16% of Ontario households that watered their lawn used a lawn sprinkler system, the installed kind, while 39% used a lawn sprinkler and 55% watered by hand with a hose or watering can, with households able to report more than one method (Statistics Canada, Table 38-10-0282-01, 2023).
The Ontario Ministry of Agriculture’s lawn maintenance factsheet calls an underground irrigation system the most efficient method of watering and says it may be considered for very large lawns. Around here that describes most estate properties, so the first question before any sprinkler system installation is whether your lawn and beds are big enough, or thirsty enough, for a zoned system to matter. On the properties we look after, the answer is usually yes.
How Ontario households that watered their lawn did it, 2023
Share of households that watered their lawn, by method. Households could report more than one method, so the bars do not add to 100.
Watered by hand using a hose or watering can55%
Used a lawn sprinkler system16%
How does sprinkler system installation work, step by step?
A proper sprinkler system installation follows the same seven steps whether it’s a front lawn in Tottenham or an estate in King City, and the order matters, because each step protects the one after it. Here’s the sequence, and what you’ll see happening in the yard.
The seven steps of a sprinkler system installation
Step 1
Walk the property and design the zones. Sun, shade, slopes, soil type, lawn versus beds, and the water pressure and flow available at the house all shape the layout.
Step 2
Book the locate with Ontario One Call at least 5 business days ahead (it’s free), and arrange private locates for the gas line to a pool heater or barbecue, wiring to sheds, detached garages and landscape lights, and septic piping.
Step 3
Set the point of connection. The system tees off your home’s water supply through a shut-off valve and a backflow preventer, installed under a plumbing permit where your municipality requires one.
Step 4
Trench and lay pipe. The pressurized mainline runs deeper than the lateral lines, and sleeves carry the pipe under any driveway or walkway it has to cross.
Step 5
Set the valves and heads. Sprinkler heads that shoot low to the ground cover the lawn zones, soaker or drip lines feed the beds under the mulch, and every head sits flush with finished grade.
Step 6
Wire the controller and sensors. A rain sensor at minimum, and a smart controller if you want the schedule to follow the weather on its own.
Step 7
Pressure test, adjust the coverage zone by zone, backfill and compact the trenches, then repair the turf with seed or sod.
A sprinkler system installation that skips a step tends to show it within a season, usually as a dry patch, a soggy corner, or a head that never quite lines up with the lawn.
When irrigation is part of a full design and build with us, it goes onto the drawings early. Every project of ours starts with a consultation at your property and a LiDAR scan that maps your land, structures and grades before design begins, and the construction documents that follow carry the grading plans, drainage coordination and layout drawings the crews build from. A sprinkler system installation planned at that stage means pipe sleeves go under a new patio or driveway while the ground is open, so nobody has to cut through finished stone later.
Do you need locates before a sprinkler system installation in Ontario?
Yes, every time, and it’s the law. Ontario One Call states that homeowners, or contractors on their behalf, must submit a locate request whether the digging is on public or private property, at least 5 business days before the work, and the request is free. The person physically doing the excavation is responsible for getting it, so when a contractor installs your system that duty sits with them, and nobody digs until every notified utility has responded.
57%
The share of Ontario homeowners who don’t realize a locate is legally required before any digging, according to Ontario One Call’s November 2024 awareness research. The same research found 1 in 4 residential digging projects results in accidental damage to underground infrastructure.
Public locates cover the gas, hydro, water and telecom lines running onto your lot. Ontario One Call is clear that private lines are yours to have marked: the gas line from the house to a pool heater or barbecue, wiring to a shed or detached garage, septic piping and the wiring to landscape lights all need a private locate before a trencher touches the lawn. Landscape Ontario, which teamed up with Ontario One Call in 2025 to spread the click-before-you-dig message, points out that locates are needed even for digs under a foot deep.
How is a sprinkler system connected to your home’s water supply?
The system tees off your home’s water supply through a shut-off valve and a backflow preventer, and that device is the part of a sprinkler system installation that carries the rules. An irrigation system is fed from the drinking water supply, and the Government of Ontario’s backflow guide defines a connection like that as a cross-connection, one that needs some form of backflow prevention device. The same guide notes that the Building Code generally requires backflow preventers where either backflow or back-siphonage may occur from a source of potential contamination, that devices are selected and installed to the Building Code and CSA B64.10, and that the work should be done by persons qualified for those purposes.
Locally, that means plumbing work with paperwork. In New Tecumseth, which runs the Alliston and Tottenham drinking water systems, the Town’s backflow program has the required device installed, where needed, under a Town plumbing permit by an authorized Master Plumber, with testing required yearly by a licensed backflow tester, and the Town treats the device as private infrastructure the homeowner maintains.
Peel Region’s backflow by-law applies to owners other than low-risk land (residential buildings of three or fewer storeys with a building area up to 600 square metres sit outside it), and it still shows how the work is meant to go: devices selected, installed and tested to the CSA standards, installed in a way that mitigates the potential for freezing, tested by a qualified person when first installed and annually after that, and installed, relocated or replaced only by licensed plumbers.
For you, the practical version is simple: leave the tie-in to a licensed plumber, keep the test report, and make sure the device is protected before winter. On a sprinkler system installation the irrigation work and the plumbing tie-in have to be coordinated, because the day the system is connected is the day the first zone can be tested.
How deep do sprinkler lines go, and how are the zones laid out?
Shallower than you might expect, because irrigation pipe is emptied every fall and never sits full through an Ontario winter. Landscape Ontario’s guidance for residential systems puts lateral lines about 10 inches deep to the top of the pipe, so a standard 8-inch shovel blade can’t reach them, with 12 inches better still, and the pressurized mainline 12 to 18 inches down. That’s deep enough for edging, planting annuals and a core aerator, and shallow enough that a repair is a small dig.
Zoning is where the design earns its keep. OMAFRA’s factsheet notes that slopes, areas near buildings, curbs and sidewalks, and light soils need more water, while low-lying areas, shaded areas and heavy soils may not need watering as often, so a well-designed system groups areas with similar needs onto their own valve and runs each for a different time.
Lawn zones use sprinkler heads that shoot low to the ground, which York Region recommends to reduce water waste, and beds do better on soaker or drip lines under the mulch; a soaker hose under the mulch is what York’s at-home water efficiency guide calls the best way to water a garden. The guide has a name for grouping plants by the water they need: hydrozoning.
This is where a full property scan pays off. Before design begins on our projects, a LiDAR scan captures a digital twin of the land, structures and grades, and the drainage and grading plans are drawn from that. Those are the same facts a zone layout depends on, because a zone drawn without the grade in front of it ends up with a soggy low corner and a dry crest.
Lateral lines sit shallow on purpose, around 10 inches to the top of the pipe, because the whole system is blown empty before the first frost.
When is the best time to install an irrigation system in Ontario?
Spring, from the time the ground can be worked until the summer heat sets in, or late summer into early fall, and if you have a choice, take the fall slot. The reason is the lawn. A sprinkler system installation leaves trench lines through the turf that get repaired with seed or sod, and OMAFRA’s lawn establishment guide says the best time to seed in southern Ontario is mid-August to mid-September, when soil moisture and temperature conditions are optimal for germination. The same guide says spring seeding should happen as soon as the ground can be worked, and that midsummer seeding is difficult unless irrigation is available to keep the seeded areas moist, which, happily, it now will be.
A fall install also lines up with the calendar in a useful way. The system is tested while the grass is still growing, the repaired turf roots in before winter (OMAFRA notes new sod is usually rooted within about two weeks), and the first blowout happens a few weeks later, before the first frost. A spring install gives you a full season of use, with the trade-off that the trench lines heal more slowly once the heat arrives.
Keep the municipal calendar in mind too. York Region’s outdoor water-use bylaws run from May 15 to September 30 unless a municipality says otherwise, with odd-numbered houses watering on odd days of the month and even-numbered houses on even days. In King Township, home to King City and Nobleton, outdoor watering is permitted from 6 a.m. to 9 a.m. and 7 p.m. to 9 p.m. on your assigned day, and running an irrigation system counts as outdoor water use. A controller gets programmed around those rules on the day of the sprinkler system installation.
Should you add a smart controller and a rain sensor?
Yes to both, and most people already run some kind of timer: Statistics Canada reports that 88% of Ontario households that used a lawn sprinkler system in 2023 ran it on a timer. A smart controller goes a step further. York Region describes it as using sensors and Wi-Fi to decide when and how much to water, and Peel Region notes that rain sensors prevent the system from watering during rainfall and that in spring and fall you only need half the run time you do on the hottest days of summer. Adding both during a sprinkler system installation is far easier than retrofitting them later, because the wiring goes in with the valves.
Whatever controls it, the target is the same. OMAFRA’s guidance is to irrigate at least once a week with 2.5 cm of water when there isn’t enough rainfall, in the early morning when there is little or no wind, and to be wary of evening watering, which may encourage disease. York Region adds the reason morning works: while the sun is low, the water reaches the roots instead of evaporating.
A straight-sided jar on the lawn during a 15-minute cycle shows what each zone is putting down, and OMAFRA counts about 2.5 to 4 cm in the jar as adequate. It’s the check we’d suggest the first week a new system is live, and our guide to a healthy lawn covers the rest of the routine.
What happens to your system each fall and spring?
Two visits a year keep an in-ground system honest. In the fall, before the first frost, the sprinkler system valve is shut off and an air compressor blows all of the water out of the system, which is exactly the winterizing Peel Region describes, and the backflow preventer gets the same care, since Peel’s by-law asks for devices installed in a way that mitigates the potential for freezing. In the spring, the system gets a tune-up: a check for leaks and broken heads, and a look at the schedule before the watering season starts. Those two visits are the part of a sprinkler system installation that never really ends.
Irrigation systems sit inside our residential lawn care program alongside mowing and edging, fertilization and weed control, aeration and overseeding, and seasonal clean-ups, so the watering side of the yard is looked after along with everything else growing in it. After a design and build, most of our clients move into our estate property care program, where the same team maintains the landscape so it matures and performs exactly as designed. For a certified set of eyes on an older system, Landscape Ontario created the Water Smart Irrigation Professional program with Peel and York Regions, and both regions point homeowners to it.
Sprinkler system installation questions we hear most
Can I install a sprinkler system myself?
Parts of it can be. Once the locates are done, the trenching and the lateral pipe on a small lot are within a handy homeowner’s reach. Two parts can never be skipped or improvised: the locate, which Ontario One Call requires before any digging even on your own property (you can request it yourself, and it’s free), and the tie-in to your home’s water supply, which needs a backflow preventer selected and installed to the Building Code and CSA B64.10 by a qualified person, and in New Tecumseth under a Town plumbing permit by a Master Plumber. Zone design and water pressure are the hardest parts to get right without instruments, so it’s worth having the layout checked.
Do I need a permit for sprinkler system installation in Ontario?
The part that usually carries a permit is the backflow preventer at the point of connection, because that’s plumbing. The Town of New Tecumseth, for example, has the device installed, where needed, under a Town plumbing permit by an authorized Master Plumber, and Peel Region’s backflow by-law, for the properties it covers, has devices installed, relocated or replaced only by licensed plumbers. Check with your own municipality before the plumber is booked.
How deep does a sprinkler line need to be in the ground?
Landscape Ontario’s residential guidance is about 10 inches to the top of the lateral pipe, so an 8-inch shovel blade can’t reach it, with 12 inches better, and the pressurized mainline between 12 and 18 inches deep. The lines stay shallow on purpose, because they’re blown empty every fall.
What’s the best month for a sprinkler system installation in Ontario?
Late August into September is the sweet spot, because OMAFRA’s best seeding window in southern Ontario is mid-August to mid-September and the trench lines heal fastest then. Spring works well too, as soon as the ground can be worked, and it gets you a full first season. Midsummer is the hardest time to establish turf from seed, so a July install means a little more care on the seeded strips.
Does a sprinkler system need to be winterized in Ontario?
Yes, every year. Peel Region’s advice is to shut off the sprinkler system valve before the first frost and use an air compressor to blow all of the water out of the system, or to call a certified Water Smart Irrigation Professional if you don’t know how to do it yourself. The backflow preventer needs the same care, since Peel’s by-law asks for devices installed in a way that mitigates the potential for freezing in the first place.
Will the trenching wreck my lawn?
It looks rough for a couple of weeks, then it disappears. Trench lines from a sprinkler system installation are backfilled and compacted so they don’t settle into a groove, and the strip is repaired with seed or sod. OMAFRA notes new sod is usually rooted within about two weeks, and seed sown in the mid-August to mid-September window establishes fastest, which is why we lean toward fall installs.
If you’re planning a sprinkler system installation for this fall or next spring, or you’d like irrigation folded into a bigger backyard project, we’d be glad to walk the property with you. Call us at 905.936.9494 or schedule a consultation, and we’ll look at the grades, the water supply and the planting you have in mind, then plan the zones as part of your residential lawn care program or your design and build. We work across Caledon, King City, Nobleton, Mono, New Tecumseth and the surrounding areas.
