Public spaces such as parks and reserves are an important facet of community life, but taking care of them in a sustainable and economical way can be challenging. A new smart irrigation trial is using innovative technology to help councils keep their green spaces green while reducing water consumption.
Ranked the fourth greenest city in the world, Sydney has over 155m2 of green space available per person.(1) Maintaining these green spaces requires comprehensive irrigation schedules, which can consume significant amounts of water.
Sydney Water’s Segment Manager Circular Economy, Greg Ingleton, said that Sydney Water’s smart irrigation trial has been designed to address this challenge, with estimates that it can help councils reduce their water use at parks and ovals by up to 20 per cent.
The trial includes a smart irrigation system that uses soil moisture probes and smart meters to measure water consumption, which can be analysed via an online dashboard.
Four councils are participating in the trial, with 22 parks and reserves involved and approximately 160 sensors installed across them.
Maintaining green spaces
Mr Ingleton said that the software in the trial can be tailored in a variety of ways; for example, the irrigation schedule can be changed within minutes in response to a council’s budget, or reductions due to water restrictions in dry periods. Irrigation budget adjustments mean that irrigation levels can be reduced from 100 per cent down to 80 per cent, which still allows for green parks and ovals.
“You might not be getting as lush of a green as you were hoping for, but you’re still getting some greening.”
Mr Ingleton highlighted that this is particularly impressive when compared to the alternative.
“When you go from 100 per cent to zero due to water restrictions, you don’t get any of that greening.
“That’s the beauty of it – it’s incrementally applicable and incredibly flexible for councils.”
Saving water on a rainy day
One of the benefits of the software used in the trial is its connection to the Bureau of Meteorology, which enables the software to produce an irrigation schedule based on upcoming weather events.
“The software incorporates the weather for the next seven days – if there’s a big rain event coming up, you can turn the irrigation off. If there’s a dry period approaching, then it’ll tell you to put the water on.”
Mr Ingleton said that this is one of the best features for councils as it eliminates ‘set it and forget it’ water wastage.
“A lot of councils will set their irrigators to come on twice a week. It will then turn on regardless of the weather and this is where the water wastage occurs because the irrigators will continue to turn on, even when large rain events
are forecast.”
Water needs vary greatly depending on the weather conditions, and cloudy weather will require less water than when it’s a hot, sunny day. Having an irrigation schedule that is not easily adjustable to account for weather conditions may result in too much water being used in cloudier weeks and not enough in hot, dry weeks.
“Once your grass dies, watering it again the following week won’t bring it back to life,” Mr Ingleton said.
Customisable irrigation schedules
Developed for the agricultural sector, the software used in the smart irrigation trial allows users to enter information about the size of the area, soil type, the kind of crop being grown or turf being used, the amount of water used previously and the desired level of green.
The system uses this information in combination with weather data from the Bureau of Meteorology and input from a flow meter to determine irrigation schedules. Soil moisture probes also communicate how much water is being used and what the response has been within the soil.
“When it comes time for irrigation the next week, the soil probes can detect, for example, that the roots are dry and the vegetation is not as healthy as you have programmed it to be.”
Soil probes at council parks and reserves are installed underground and communicate with the other technology by sending a signal to the cloud via a SIM card.
“The system operates on the 4G network, similar to a mobile phone. The soil probes and smart meters send their information to the software and then the councils access the dashboard to get their schedule for the upcoming week.”
Councils with existing infrastructure that cannot be directly controlled by the software can manually enter the irrigation schedule for the upcoming week.
Installation and maintenance
The soil moisture probes and sensors were mostly installed by Sydney Water’s technical teams, a process that Mr Ingleton said takes about half an hour.
“The process is as simple as getting a drill with a large bit to dig a hole into the dirt before creating another small hole for the communication system. After that, you put the probe and the communication system in their respective holes, cover them up and walk away.”
Mr Ingleton said the software setup process is also easy and takes councils approximately 20 minutes to enter all the required information.
The systems themselves are robust and require limited maintenance.
“If a system fails after several years, it can easily be taken out and replaced.”
Mr Ingleton said the low cost of the smart irrigation infrastructure combined with the savings made during its life, make smart irrigation an affordable choice for councils when replacements are required.
Another benefit of smart irrigation systems is leak detection – the software contains detailed information about watering schedules so it becomes obvious to operators when water is being used outside of the schedule.
“This is helpful not just for optimising irrigation, but for saving water and ensuring leaks are addressed quickly,” Mr Ingleton said.
Unseasonal challenges
The unusually wet conditions of the previous two summers have caused some limitations for the trial. However, despite the lack of extended periods of extreme heat, Mr Ingleton said the trial is still producing positive results.
“Though we haven’t had the ideal summers for the trial, we are still seeing some good results. As the system was designed, there have been instances in which irrigation was stopped because of an upcoming rain event.
“We have also seen some water overuse, but nothing too drastic.”
Mr Ingleton said that although the team is hoping for some more varied summer conditions to fully test the program, participating councils have still seen savings in both water and money.
In conjunction with the smart irrigation data from the parks and ovals, Mr Ingleton said that the smart irrigation software provider has recently introduced Planet Data – a satellite that can assist with measuring the soil moisture and vegetation health at the participating parks and reserves.
“The satellite imagery can identify some issues with the irrigation systems before there’s any evidence on the field – it gives councils another avenue to remotely manage their parks and reserves.
“Councils are often taking care of a lot of parks, so anything we can do to reduce their workload is a bonus,” Mr Ingleton said.
Looking to the future
In addition to Sydney Water exploring different commercial models to attract more councils to get on board, Mr Ingleton said the utility is also looking to maximise the benefits delivered to the community.
Another technology being trialled as part of the project is air temperature sensors. Mr Ingleton said that there are approximately 160 located in parks and reserves around Greater Sydney, with plans to install even more. The sensors feed their information to a live data map, with Sydney Water working on making this information available to the community on the Sydney Water website.
“When you’ve got young children, it can be hard to know what activities are safe to do in the summer heat. If you can jump onto a website and find out what the temperature is at your favourite park, it makes the decision a lot easier.”
It is hoped that the smart irrigation trial will have more far-reaching impacts than reduced water consumption and healthy council parks. Mr Ingleton said that Sydney Water is taking a more holistic approach on how the information gathered can be made available to residents who live near parks to help them with the irrigation of their own open spaces.
“The next iteration of this work centres around community education. Urban heat islands can’t be addressed by councils watering their parks alone. We need to be able to educate the community on irrigation and how to best care for their own space.”
Featured image: Probe installation underway in a local park. Image: Emma James, Sydney Water
Footnotes:
- How green space and health insurance can support your mental health, https://www.comparethemarket.com.au/health-insurance/features/the-greenest-cities-in-the-world/
