Saving Water Is Easier Than You Think!

Article republished with permission from Irrigation Australia. Article was originally published in the Spring 2025 edition (Issue 82) of The Overflow, the official quarterly publication of Irrigation Australia (WA Region).

Why Councils Need to Act Now

Councils play a key role in maintaining green spaces in cities. Irrigation is essential for keeping these areas healthy. But Perth’s water supply has been under pressure for years. Declining rainfall, urban growth, and heavy use of groundwater have all added stress. The Gnangara aquifer has been hit the hardest.

As part of efforts to protect groundwater, councils north of the Swan River will see a 10% cut to water allocations by 2028. This means they must keep parks and sports fields attractive and fit-for-purpose while using less water.

This article looks at how the City of Bayswater is tackling this challenge. They used SWAN Systems software with their Aquamonix Rainman controllers to optimise irrigation schedules and save significant amounts of water.

Water Allocations: A Tightening Budget

Water licences for public green spaces in Perth usually allow 7,500 kL/ha. These areas include sports fields, parks, gardens, and street verges. Councils have some flexibility with how water is used within a licenced area. For example:

• A premium oval might need 10,000 kL/ha
• A shaded park could do well with less than 5,000 kL/ha

This approach makes it possible to water each type of space properly without going over the allocation.

But the coming cut to an average allocation of 6,750 kL/ha in 2028 will make things tough. Councils will need better infrastructure, smarter water management, or both.

Finding Potential Water Savings

The first step to knowing if water savings are possible is knowing when and where water is used.

The City of Bayswater irrigates many sports fields using Aquamonix Rainman controllers. Since 2018, they’ve used SWAN Systems to collect controller data on 15 ovals. SWAN automatically collects and analyses irrigation and weather data, tracks changes in soil moisture and compares irrigation applied to actual turf water demand over time.

These data provided some important insights ( Figure 1A ):

• Irrigation usually started at the right time in September
• Watering ramped up correctly through spring and early summer
• But irrigation stayed too high late in summer and into autumn

So, February to April became the clear target for savings. Soil moisture readings confirmed this: The sports fields stayed wet longer than needed.

The Shoulder Season Problem

The data show that autumn offers the biggest chance to save water. But this can be tricky. The weather changes a lot, and turf managers are busy. Even if they check soil data, adjusting irrigation schedules may not be straightforward. They must decide how much to cut back or increase watering, all the while watching for rapidly changing weather conditions. Because of this, managers may keep irrigation high in autumn as a “safety net” against sudden heat. This is where SWAN Sync comes in.

Smart Scheduling with SWAN Sync

SWAN Sync lets SWAN send optimised irrigation schedules straight to controllers. SWAN predicts how much water the turf will need each day over the next week using weather, irrigation and soil moisture data, along with rainfall and evapotranspiration forecasts.

The process is simple:

1. In SWAN, click “optimise”
2. Review, approve and save the schedule
3. The system sends it to the controllers automatically

This takes about 15 minutes, once or twice a week. It means irrigation aligns with current conditions, saving water without extra effort.

Does it Save Water?

Yes. Starting with the 2022-23 season, Bayswater added SWAN’s schedule optimisation with SWAN Sync to two ovals – Emberson and RA Cook. Comparing the years before and after implementing SWAN Sync:

• In 2019, 2020, 2021 and 2022, water use was between 30-40% above turf demand from February – April
• In 2023, 2024 and 2025 the excess for the same period dropped to under 10% (an acceptable buffer against under-irrigating)

A comparison of irrigation patterns before and after implementation of SWAN Sync at Emberson Reserve is shown in  Figure 1 . This shows irrigation matched turf needs much better after using SWAN Sync ( Figure 1B ).

Figure 1 . Monthly turf water demand (green bars) vs. irrigation applied (dark blue bars) at Emberson Reserve.

A. Sep 2021 – May 2022  ( before SWAN Sync ): Irrigation was scheduled using accepted standard practice, with monthly budgets based on historical average evapotranspiration. The highlighted months (Feb–Apr 2022, orange box) show periods of excess irrigation compared to actual turf demand. The arrows indicate potential water savings.

B. Sep 2022 – May 2023  ( after implementing optimised irrigation scheduling with SWAN Sync ): The highlighted months (Feb–Apr 2023, orange box) show a marked reduction in excess irrigation, with application much closer to turf water demand.

How Much Water Can Be Saved?

Every season is different. For example, 2023-24 was one of Perth’s hottest and driest years, with almost no rain from September to May. Turf needed about 15% more water in 2023-24 than average. This illustrates the challenge of comparing between years to determine whether savings have been made.

However, if a consistent excess of irrigation applied relative to actual crop demand is mitigated by a change in practice, then it’s clear that water savings have been achieved. SWAN Sync has improved annual water application efficiency at the two ovals:

• Emberson Reserve: at least 20% more efficient
• RA Cook Reserve: about 15% more efficient

This equates to an average of 1,500 kL/ha saved for these high-use ovals. Published scientific research shows smarter scheduling can often cut water use by 20% or more. Importantly, there was no loss of turf quality due to the water saving. This was monitored by satellite imagery (NDVI) that showed greenness was maintained through the periods of optimised scheduling and SWAN Sync.

Because of this success, Bayswater will roll out SWAN Sync at three more ovals in 2025.

The Data is Already Available – Let’s Use it to Save Water!

Councils do their best with limited time and, often, aging infrastructure. Continuous data analysis is the only way to provide actionable decision support that drives immediate improvements in water efficiency. Fortunately, most councils already collect this data. They just need to use it! By combining SWAN’s data analysis with SWAN Sync-enabled controllers, irrigation managers get an easy, push-button solution to improve irrigation efficiency and cut water use.

“The introduction of SWAN Systems into the City’s irrigation monitoring tools has significantly enhanced our approach to predictive scheduling.

The SWAN Sync Trial has highlighted the potential for more efficient water use, and we intend to expand this trial by incorporating three additional grounds with differing characteristics to the current sites. We look forward to analysing the results of this expansion.

The moisture sensor data collected from the current sites often aligns closely with the calculations from the SWAN Systems, creating a synergistic relationship that boosts our confidence in our irrigation strategies.

Our field staff, already well-versed in the specific needs of the various grounds, are responsible for programming the irrigation systems. The insights provided by SWAN Systems serve as a valuable reference tool, further assisting them to make informed decisions on irrigation management. Together, these tools will enhance our ability to optimise water usage while maintaining healthy landscapes.”

Wayne Peace , City of Bayswater

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• Saline Water Irrigation
• Irrigation
• Irrigation & Water Management
• Water Treatment Systems
• Irrigation & Water Management
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