How to winterise your reticulation in Perth

Perth's winter sprinkler ban runs from 1 June to 31 August. Scheme-water reticulation is off for three months. This is the right window to actually shut your system down properly, check the bits that fail silently, and queue up spring start-up so you're not running with a broken station in September.

Most of this is twenty minutes of work. None of it costs money unless you find something broken.

Why bother - I'll just leave it

Two reasons.

First, an automatic controller left "on" can fire by accident after a power cut. Some controllers default to a factory program when the backup battery dies, and that program may not match the winter ban. Best case: a neighbour reports you and Water Corp issues a warning. Worst case: your system runs a leak undetected for weeks while you assume it's off.

Second, three months is exactly long enough for slugs, ants, and tree roots to do unhelpful things inside your valve boxes. If you find a problem in June, you've got the whole winter to fix it. Find it on 1 September with the daytime ban about to start and you're scrambling.

The shutdown - what to do in the first week of June

Step 1: Turn the controller fully OFF

Not "Mist", not "Pause", not "Rain Delay". The dial or switch should be in the OFF position. On most controllers this disconnects the solenoid outputs entirely so the system can't fire even if the rain sensor fails or the program corrupts.

On smart controllers (Hunter Hydrawise, Rain Bird ESP-TM2, Rachio), use the app to set the controller to Standby or Off mode for the full ban window. Don't rely on weather-based skip - cold rainless weeks happen in Perth winter, and a smart controller in "auto" mode will try to water.

Step 2: Leave the backup battery in place

Most controllers run a small 9V battery to retain the program through power cuts. Leave it in. If you pull it now to "save the battery", you'll come back in September to a controller that's reset to factory defaults and you'll have to re-enter every station, run-time, and watering day.

Step 3: Open one solenoid manually for 30 seconds

Pick the lowest valve box on your property - the one furthest downhill. Open the manual bleed on one solenoid. Let it run for 20-30 seconds, then close it. This drains residual pressure from the lateral lines and makes any leak at the solenoids visible during the dry months.

You'll get a visible patch of damp earth. That's expected. If the patch is still soaking three days later, you've got a leak. Get it fixed during winter rather than in the spring rush.

Step 4: Cap exposed risers if you've got dogs or kids

If your sprinklers sit proud of the lawn (older systems often do), winter is when toys, hooves, and shoes break them. Slip a $2 plastic cap over any exposed riser. Sounds trivial - it saves a $250 call-out in spring.

Step 5: Note the controller program before doing anything else

Take a phone photo of the controller display showing each station's run time and start time. Photograph the watering-days screen and the seasonal-adjust setting too. If the controller resets over winter for any reason, you've got the program. This takes 90 seconds and saves an hour of guessing in September.

What to check during winter

Three things, once a month each.

Valve boxes

Pop the lids on each box. Look for:

• Slug damage to wiring. Slugs love valve boxes. They chew through the wire insulation. If you see exposed copper, get a installer to splice it with a waterproof connector ($120-$180 visit).
• Ant colonies in solenoids. Sounds weird, but ants will nest in a dry solenoid through winter and the colony can block flow when you start up in spring. Flush each solenoid with a hose for 5 seconds.
• Standing water in the box. If a box is full of water in July, something is leaking. See signs your reticulation needs repair for what to do.

Controller

Once a month, walk past and confirm the display is off (or in standby on smart units). If a previously-off controller has come back to life, the most likely cause is a power cut that triggered a factory reset. Set it back to off and check the days are still correct.

The water meter

Once a month, with all taps off and no internal water use for at least 10 minutes, look at the meter. The dial should be completely still. If it's turning, something is leaking - could be retic, could be inside. Worth investigating now, not in October.

Frost protection (Hills suburbs only)

Most of Perth metro doesn't see frost hard enough to crack reticulation. The exception is the Perth Hills - Kalamunda, Mundaring, Roleystone, parts of Lesmurdie - where overnight temperatures drop below zero on a handful of nights per winter.

If you're in that band:

• Drain the mainline by closing the upstream isolation valve and opening the lowest point in the system.
• Insulate any above-ground pipework with foam pipe lagging from Bunnings (about $8/m).
• Wrap the bore pump pressure tank if it's outdoors and unsheltered.

On flat metro suburbs (Mount Lawley, Subiaco, Como, anywhere within 10km of the coast), skip the frost steps. Not worth the work.

Spring start-up - first week of September

Run this checklist on or before 1 September. The winter ban lifts on the 31st of August, and the daytime watering ban (9am-6pm) starts on the 1st, so your first watering is overnight on the first eligible day of September.

Spring start-up checklist

1. Confirm your watering days. Check your suburb's watering days - they're set by the last digit of your street number and don't change, but it's worth a confirmation in case Water Corp adjusted your postcode group.

2. Re-program the controller. Set the current day-of-week, start time (3am to 5am is standard), watering days, and run times for each station. Use your phone photo from June if the controller reset over winter.

3. Run each station manually for 60 seconds. Watch each sprinkler. Look for:

   • Geysers (snapped riser)
   • Sprinklers not popping up (debris or low pressure)
   • Sprinklers stuck open (perished seal)
   • Stations that won't fire at all (dead solenoid)

4. Check the spray pattern on rotors and MP rotators. Six months of dust and three months of inactivity will have clogged some nozzles. A $5 nozzle pull-and-clean per affected head is worth the effort.

5. Check the rain sensor. If you've got one mounted on a fence or eave, climb up, pop the cap, check for cobwebs, wasp nests, or a swollen cork that hasn't relaxed. Trigger it manually to confirm the controller registers the input.

6. Set seasonal adjust to 100% if you've got that feature. Spring evapotranspiration in Perth ramps fast - your June settings (if you had any) won't match September demand.

7. Run the full cycle the first night and check coverage the next morning. Dry patches in the lawn 12 hours after watering = a station that didn't fire, a sprinkler that's blocked, or a coverage gap.

What you don't need to do

Skip these - they're either snake oil or genuinely wasteful:

• "Winter blowout" with compressed air. Standard for cold-climate retic in the US. Pointless in Perth - we don't get freeze depth that requires it, and over-pressurised blowout damages MP rotators and pop-ups.
• Antifreeze in the lines. Don't. Aside from being environmentally problematic, no Perth installer should ever suggest this.
• Pulling the controller off the wall. Leave it mounted. The backup battery is enough.
• Disconnecting the mains supply. Optional, and most homeowners shouldn't bother. The supply pressure isn't doing harm to a system that's electrically off.

If something breaks during winter

The advantage of finding faults in June is you've got three months to fix them at your own pace. Most Waterwise-endorsed installers have lighter calendars through winter and can usually schedule a non-urgent repair within a week.

Common winter-discovered faults:

• A solenoid leaking into a valve box (found via your monthly box check).
• A controller that died over a power-cut weekend.
• An underground leak revealed by a winter rain pattern that doesn't match - one patch of garden stays wet when the rest dries.
• Rodent or slug damage to wiring that wasn't visible in autumn.

Fix in winter, not September. Spring is the busiest month for retic call-outs and you'll wait 2-3 weeks for a non-urgent slot.

FAQ

Do I have to legally shut my system down for winter?

Yes, if you're on scheme water. The winter sprinkler ban runs 1 June to 31 August and applies to all automatic and unattended scheme-water sprinklers. Hand watering is allowed any day.

What if I'm on bore water?

The legal ban doesn't apply to bores, but Water Corp asks bore users to switch off too because established Perth gardens don't need supplementary water through winter rainfall. Most bore-fed systems get shut down in practice.

Will my lawn die without watering for three months?

Established Perth lawn (couch, kikuyu, buffalo) goes semi-dormant in winter and doesn't need irrigation. Winter rainfall covers it. Newly-laid turf within the last 8 weeks of autumn may need exemption-watering - check with Water Corp.

Should I pay an installer to winterise for me?

If you've got a smart controller you're comfortable with and a system you understand, no - it's 20 minutes of DIY. If you've inherited a system from a previous owner and don't know where the valve boxes are or how the controller works, a one-off $200-$300 audit is money well spent.

What about my drip lines under mulch?

Drip lines fed from a solenoid follow the same rules - off via the controller. If you've got a dedicated drip station with a separate isolation valve, close that too.

Can I run my system once a week through winter just to keep it working?

No, not on scheme water - that's a ban breach. Established systems don't "seize up" from three months of inactivity in a Perth climate. If you're worried about solenoids sticking, the Step 3 manual-bleed during shutdown gives them a final cycle.

I forgot to winterise and it ran in July. What happens?

If a neighbour reports it, expect a Water Corp warning. Switch the controller off immediately and you're unlikely to escalate. Repeat breaches attract fines.