Irrigation plan: stations, mainline and controller schedule
The drawing that turns your hydrozones into stations, valves and pipe runs. The engineering behind it is the mini-course in Phase 8; this lesson is about producing the document and coordinating it with everything else.
Irrigation is the only service in a garden that has to be drawn before the hardscape is built and cannot be corrected afterwards without breaking something. A planting mistake is a plant. A retic mistake is a mainline under 250 square metres of new liquid limestone.
This lesson produces the drawing. It does not teach the hydraulics — that is the irrigation mini-course in Phase 8, and you should read at least hydraulics and hydrozoning and stations before you commit anything here.
One legal point first. The connection at the head of your mainline is water supply plumbing, and in WA installing or altering water supply plumbing is major plumbing work under the Plumbers Licensing and Plumbing Standards Regulations 2000 — a new or replacement testable backflow prevention device always counts. That is a licensed plumber, not you. Draw the connection, specify the device, and put a plumber in the schedule of works. Check licences on the Building and Energy licence search, which also covers the electrician you need for a 240 V controller supply or a pump circuit.
What a professional does at this stage
They design backwards from the watering window, and they draw the mainline before they draw a single sprinkler.
Most people start with where the heads go. A professional starts with how many minutes they are legally allowed, because that number caps the station count, which caps how finely they can hydrozone — which sometimes sends them back to change the design.
The mainline and the sleeves under paving go in during earthworks, before the base is compacted. If the plan does not exist by then, someone trenches through finished work later. And because the irrigator, the plumber and you-in-five-years all have to read it, every valve gets a number and every mainline run gets an offset dimension from a permanent edge. That drawing becomes the as-built.
Start with the run time budget
Perth is on two rostered watering days a week, once per day, before 9am or after 6pm, and bore users get the same roster and hours. Look up your own days on Check your watering days; breaching it is a $100 on-the-spot fine, and the roster and winter ban lesson covers the rules in full. Treat the pre-9am window as your budget, take run times from the Water Corporation’s published application rates, and add them up:
| Station | Hydrozone | Emitter | Run time |
|---|---|---|---|
| 1 | Back lawn | Gear drive rotary | 35 min |
| 2 | Front lawn | Gear drive rotary | 35 min |
| 3 | Feature beds, west sun | Dripline | 35 min |
| 4 | Feature beds, south shade | Dripline | 30 min |
| 5 | Native / low-water bed | Dripline | 30 min |
| 6 | Pots and entry | Micro spray | 15 min |
| Total | 3 h 00 min |
Start at 5:30am and it finishes at 8:30am, inside the window. A seventh station pushes the 9am boundary. Cycle-and-soak on deep Bassendean sand needs you to be cleverer, not longer: split the lawn stations into two shorter passes and order the program so the other stations run during the soak interval. Total minutes barely change; the water gets time to move down instead of running off.
If it does not fit: increase available flow so stations can be bigger, shrink the high-water hydrozone, merge two areas that genuinely share a water requirement, or accept manual care for one small area. A second start time is not an option — the rule is once per rostered day. If you are unsure whether cycle-and-soak counts as one watering event, ring Water Corporation on 13 10 39 rather than guessing.
Stations: one hydrozone, one emitter type, one aspect
Anything sharing a solenoid gets the same minutes, so anything with a different water requirement needs a different solenoid.
| Never share a station | Why |
|---|---|
| Lawn and garden bed | Different rates, different depths, different schedules |
| Spray and rotary heads | 35–45 mm/h against 10–20 mm/h on the same valve |
| Full sun and deep shade | Same plant, twice the demand |
| Dripline and sprinklers | Completely different application logic |
| Slope top and slope bottom | Bottom stays wet, top stays dry |
| Established natives and new planting | The new planting needs establishment water the natives will rot in |
That last row matters on a renovation. If you are keeping mature plants and adding new beds, the new beds get their own stations — you will run them hard for the first summer and then wind them back, which is impossible on a shared valve.
Carry the zone boundaries straight off the hydrozone plan. Do not redraw them by eye here.
The mainline: route it where nobody will ever dig again
The mainline is pressurised whenever the system is on. A lateral leaks only while its station runs; a mainline leak runs 24 hours a day into sand, and you find out via the bill.
- Lodge a BYDA request first. Free, and it shows where the water service, gas, power and comms run. Hand-dig to expose anything near the route. On a renovation, assume BYDA misses the previous owner’s unmarked poly and the dead power run to the shed — cross-reference your own services survey.
- Run it straight, parallel to a permanent edge, offset dimensioned. “1.2 m off the southern boundary fence” is findable in ten years. A curve through a lawn is not.
- Never under future paving, concrete, decking or a slab. Cross at right angles, inside a sleeve.
- Sleeve every hard-surface crossing and oversize it. 100 mm conduit, capped, both ends staked and on the plan, plus a separate sleeve for the lighting cable. A few dollars a metre now; several hundred to retrofit through a finished driveway.
- Keep out of the drainage. Overlay the drainage plan and stay clear of soakwell excavations and stormwater trenches.
- Keep out of the root plate of trees you are keeping, and out of anywhere you will cultivate deeply.
Perth trade practice is a deeper trench for the mainline than for laterals. Confirm the cover depth your supplier and installer specify, and put that number on the drawing.
Valve boxes you can actually open
- Group valves into manifolds of two to four in one rectangular box rather than scattering single valves. Fewer places to look, one wiring run.
- Boxes go in mulched garden bed — never in lawn, never inside a paved area. A box in turf gets mown over, sinks and disappears.
- Lid flush with finished level, taken off the levels and grading plan, not off today’s ground, and with nothing large planted in front of it.
- Number every valve on the drawing and on the lid. Station 3 on the plan is the lid marked 3.
- Show the master valve and controller position, and note the wiring: one core per station, plus a common, plus at least two spares. Spare cores are the cheapest insurance in the system.
Coordinating with the rest of the set
Overlay this plan on each other drawing before you call it finished.
| Overlay with | The question it answers |
|---|---|
| Scaled layout plan | Does the mainline cross anything hard, and where are the sleeves? |
| Levels and grading | What level are the valve box lids? |
| Drainage plan | Do any trenches or soakwells clash? |
| Planting plan | Is every plant in the hydrozone its station is scheduled for? |
| Lighting plan | Can the two share trenches and sleeves? |
| Existing garden audit | What of the old system is reused, and is it worth it? |
The establishment program is part of the drawing
New planting cannot survive on two days a week in its first month, so Water Corporation grants a watering exemption for a new lawn or garden — up to 42 days from installation between 1 October and 31 March, and up to 35 days between 1 April and 30 September. Breaching the conditions risks a $500 fine, and the property owner carries that risk, not the installer. Apply on the day you plant; the clock runs from installation, not application.
Put two programs on the drawing — an establishment schedule and the ongoing schedule, with the changeover date — then add the Water Corporation’s seasonal adjustment percentages as a table on the same sheet: 100% January and February, 80% March, 60% April, manual only in May and September, off June to August for the Switch-off, 60% October, 80% November, 90% December. One set of run times, one dial — scheduling and uniformity tunes those numbers against catch-cup data once the system is in. Note the Switch-off on the drawing too: 1 June to 31 August, bores included, and if your build lands in that window you are hand-watering unless your supply is a rainwater tank.
Safety on the day this gets built
Trenching in Perth sand is more dangerous than it looks: dry sand walls collapse without warning, so keep trenches shallow and battered, and never put your head below ground level in an unsupported trench. Hand-dig inside the exclusion zones on your BYDA plans, do not work alone in a trench in summer heat, and leave the connection and the backflow device to the licensed plumber.
What happens to this next
The finished plan feeds the sleeve and trench line items in your quantity take-off, the sequencing in the schedule of works, and the Phase 8 mini-course where the pipe gets sized and installed. The next lesson produces the planting plan and schedule — and the first thing it asks is which station every plant on it belongs to.
Checklist
- Every hydrozone maps to one or more stations, never mixed
- Mainline route avoids future excavation and structures
- Valve box positions are accessible and marked
- Station run times fit inside your legal watering window
Where to go deeper
Every link below was fetched and checked before it shipped. Nothing here is a guess.
- Freetool5 minPerth / WA
Check your watering days
Water Corporation
Why this oneEnter your street number and postcode and it returns the rostered watering days for your actual property, which is the number your whole controller schedule is built on. It also states the rules you are designing against: water once, before 9am or after 6pm, on your rostered days only; garden bore users in Perth and Mandurah are on the same roster and the same hours as scheme water users; and breaches carry a $100 on-the-spot fine with inspectors operating seven days a week.
Link checked 2 Aug 2026
- Freegovernment10 minPerth / WA
Sprinkler Switch-off
Water Corporation
Why this oneThe winter ban runs 1 June to 31 August every year across Perth, Mandurah and parts of the South West and Great Southern, and it applies to garden bores as well as scheme water. Two details on this page change an irrigation plan: irrigation fed from a rainwater tank is not covered by the switch-off, and new lawns and gardens can be watered under an exemption you have to apply for. If your build lands in winter, this page decides whether you can commission the system at all.
Change this for PerthChecked on 2 August 2026, the Water Corporation waterwise homepage was carrying the live banner that the Switch-off is currently in effect. Confirm the areas covered with the postcode checker rather than assuming your suburb is in or out.
Link checked 2 Aug 2026
- Freegovernment15 minPerth / WA
Apply for a watering exemption
Water Corporation
Why this oneThe page that lets a newly planted garden be watered outside the roster while it establishes, and the one most renovators find out about too late. It covers new garden and new lawn including roll-on, runners, shredded lawn and seed; the period is up to 42 days from installation between 1 October and 31 March, and up to 35 days between 1 April and 30 September. It is explicit that the property owner, not the installer, carries the compliance risk, and that breaching the conditions risks a $500 fine.
Change this for PerthApply on the day of installation. Applying late still works but the clock runs from the installation date, not the application date, so you lose the days you waited.
Link checked 2 Aug 2026
- Freecalculator5 minPerth / WA
How long should I run my sprinklers for
Water Corporation
Why this oneThe published application rates that turn a station list into minutes, which is the only way to check the fourth item on this lesson's checklist. As at August 2026 it gives pop-up and fixed spray at 35 to 45 mm per hour needing 13 to 16 minutes for the 10 mm target, micro spray the same, rotary at 10 to 15 mm per hour needing 40 to 60 minutes, gear drive rotary at 10 to 20 mm per hour needing 30 to 40 minutes, and dripline at 15 to 20 mm per hour needing 30 to 40 minutes.
Change this for PerthThe 10 mm per watering day target is a Perth default for sandy soil on a two-day roster, not a plant water requirement. Hydrozoning is exactly the process of departing from it deliberately, and Phase 8 revisits the number with catch-cup data from your own block.
Link checked 2 Aug 2026
- Freegovernment10 minPerth / WA
Why you need to adjust your irrigation
Water Corporation
Why this onePublishes a month-by-month seasonal adjustment table so your controller schedule can be a single set of run times with a percentage against it rather than twelve separate programs. For Perth and the South West it gives 100% in January and February, 80% in March, 60% in April, manual use only in May and September, the Sprinkler Switch-off from June to August, then 60% in October, 80% in November and 90% in December. Put that table straight onto your drawing.
Link checked 2 Aug 2026
- FreedirectoryPerth / WA
Find a Waterwise Irrigation Design Shop
Irrigation Australia / Water Corporation
Why this oneThe searchable list of endorsed businesses, filterable to Waterwise Irrigation Design Shop Member as a separate category from Waterwise Garden Irrigator Member. Design shops are the ones that will size pipe, check pressure loss and lay out heads from your scaled plan, usually at no charge if you buy the parts from them. For a homeowner who has done the hydrozoning honestly, walking in with a dimensioned layout plan is the cheapest competent hydraulic design available in Perth.
Change this for PerthEndorsement means the business has been trained in the program's best-practice guidelines and appointed to deliver it, not that it is the cheapest or the most independent — a design shop sells product. The directory also lists Victorian members, so filter by state.
Link checked 2 Aug 2026
- Freegovernment15 minAustralian
Before You Dig Australia — Duty of Care
Before You Dig Australia
Why this oneFree asset plans from every utility that owns something under your block, and the page that sets out what you are expected to do with them. It asks you to lodge the request at least one day before work starts, to use a skilled locator where the plans are ambiguous, to hand-expose cables and pipes rather than machine-dig onto them, and to observe the exclusion zones in the duty of care statements the asset owners attach. Do this before you commit the mainline route to paper, not on the morning you dig it.
Change this for PerthBYDA only shows registered network assets. It will not show the previous owner's unmarked poly, the abandoned power run to the shed, or the soakwell nobody recorded — which on a renovation is most of what you will hit.
Link checked 2 Aug 2026
- Freegovernment15 minPerth / WA
Information for licensed plumbers — major and minor plumbing work
Building and Energy, Department of Energy, Mines, Industry Regulation and Safety
Why this oneThe regulator's own definition of what a homeowner may not legally do at the point of connection. It classifies the installation, alteration, extension or replacement of water supply plumbing as major plumbing work under the Plumbers Licensing and Plumbing Standards Regulations 2000, and singles out a new or replacement testable backflow prevention device as always defaulting to major plumbing work. That is the item sitting at the head of your mainline, so read this before you draw the connection.
Link checked 2 Aug 2026
- Paid · Application $200 member / $300 non-member, plus $440–$670 per exam and $195–$420 annual renewalcourse6–12 months self-pacedAustralian
Certified Irrigation Designer program
Irrigation Australia (RTO 91313)
Why this oneNamed here so you know what the actual professional credential is and can ask whether the person quoting you holds it. The syllabus is the honest scope of irrigation design — principles of irrigation, soils, scheduling, valves and electrical, then system selection, hydraulic design, performance parameters and monitoring — and it expects two to three years of industry experience going in. This is not a sensible purchase for one garden; the free equivalent for a homeowner is taking your scaled plan to a Waterwise Irrigation Design Shop.
Link checked 2 Aug 2026
The rules, with sources
WA regulation changes. Each point below names its primary source and the date it was last checked — always confirm with your own council before you build.
In Perth, sprinklers may be used only once on a rostered watering day, either before 9am or after 6pm. Breaches attract a $100 on-the-spot fine and inspectors operate seven days a week. Garden bore water users in Perth and Mandurah have the same rosters and times as scheme water users.
Water Corporation ↗ · checked 2 Aug 2026
Garden bores in the Perth and Mandurah area may be used on two rostered days a week, once on the rostered day, either before 9am or after 6pm.
Be Groundwater Wise, Department of Water and Environmental Regulation ↗ · checked 2 Aug 2026
The Sprinkler Switch-off runs from 1 June until 31 August every year in Perth, Mandurah and parts of the South West and Great Southern, and applies to garden bore users as well as scheme water users. It does not apply to irrigation systems supplied from rainwater tanks.
Water Corporation ↗ · checked 2 Aug 2026
A watering exemption for a new lawn or garden runs for up to 42 days from the installation date between 1 October and 31 March, and up to 35 days from the installation date between 1 April and 30 September. Random inspections may occur and failing to comply with the exemption conditions risks a $500 fine. The property owner, not the installer, is responsible for compliance.
Water Corporation ↗ · checked 2 Aug 2026
Installing, altering, extending or replacing water supply plumbing is major plumbing work in Western Australia under the Plumbers Licensing and Plumbing Standards Regulations 2000 and must be carried out by a licensed plumber. A new or replacement testable backflow prevention device always defaults to major plumbing work.
Building and Energy, Department of Energy, Mines, Industry Regulation and Safety ↗ · checked 2 Aug 2026
You may run each irrigation station for no longer than two minutes for testing, on your rostered watering days, before 9am or after 6pm. A Waterwise Garden Irrigator may test on or outside your rostered days and during the Sprinkler Switch-off without notifying Water Corporation.
Water Corporation ↗ · checked 2 Aug 2026