Waterwise Irrigation Rebate
Eligible customers can apply to receive a rebate of up to $200 when they engage an approved garden irrigator to address specific irrigation system issues.
Learn more
•
Why you need to seasonally adjust your irrigation
In this article
Our unique WA climate means your garden needs different amounts of water at different times of the year. By adjusting your irrigation system for each season, you can keep your garden healthy while saving water for when we need it most.
First, set your sprinkler run times
Different sprinklers apply water at different rates, so the time needed to deliver the recommended 10mm of water depends on the type of sprinklers in your garden. Before setting seasonal adjustments, ensure your sprinkler run times are correctly set for your specific sprinkler type.
Recommended run times:
- Dripline sprinklers: 30-40 minutes
- Pop-up & fixed spray sprinklers: 13-16 minutes
- Rotary sprinklers: 40-60 minutes
- Micro Spray sprinklers: 13-16 minutes
- Gear drive rotary sprinklers: 30-40 minutes
Is rain on the horizon?
When rain is forecast, turn your sprinklers off and let nature do the work. Remember the Winter Sprinkler Switch-off is in place from 1 June until 31 August every year for scheme and bore water users in Perth, Mandurah and parts of the South West and Great Southern. Check if you’re included.
Next, set your seasonal adjustments
Seasonal adjustments are a percentage taken from your sprinkler run time.
As temperatures rise in summer, your garden needs more water. But in cooler months, low evaporation rates mean your garden needs much less water. Leaving your system on the same settings all year wastes water and can lead to over watering, root rot and nutrient loss in your garden.
So you don’t have to re-program each station individually, most irrigation controllers have a seasonal adjustment setting that changes all irrigation station run times at once.
Seasonal adjustment example
If your normal sprinkler run time is 10 minutes in summer, setting an 80% seasonal adjustment would make the new run time 8 minutes.
Seasonal adjustment guide
For Perth and the South West, we recommend setting your seasonal adjustment at 100% for January and February only, then gradually decreasing the percentage as the weather cools.
| Time of year | Seasonal adjustment |
| January - February | 100% |
| March | 80% |
| April | 60% |
| May | Use manually, if needed |
| June - August | Winter Sprinkler Switch-off |
| September | Use manually, if needed |
| October | 60% |
| November | 80% |
| December | 90% |
Water wiseley when the weather is cool
In spring, cooler weather and lower evaporation means your garden needs far less water than in summer. Switch your irrigation to manual and only water once on your rostered watering days.
Read a transcript of this video