OXYGEN FILES: South Australian Water is collaborating with Sydney Water, researchers and the NSW Smart Sensing Network on water saving technologies. It makes sense, really, that the driest state in the country is pretty savvy on H2O.

While catchments along the east coast of Australia received a much-needed top up in recent weeks, in South Australia, it’s still pretty dry, and recent rainfall in the upper reaches of the Murray Darling catchment could take weeks to reach the far south – if it gets there at all.

According to the latest flow reports from the SA Department of Environment, continued high temperatures and the dire dryness of the upper Murray-Darling catchment means that between evaporation and catchment absorption, splashing out on water allocations is not happening in the immediate future.

But being Australia’s driest state for both annual rainfall and surface water availability seems to have shaped a wise approach to the wet stuff.

Recycled water, demand management, desalination, water-efficiency programs and active promotion of rainwater tanks are all embedded across policy, planning and property.

Tech to the rescue

SA Water has invested heavily in solutions for both ends of the pipe – supply and demand. An ongoing community engagement campaign and specific water efficiency programs has cultivated a strong awareness of the need to be careful with water.

Recently it has also been piloting smart meters across a range of different user groups, with more than 730 currently installed around the state.

A spokesperson for SA Water says they include 115 for about 70 businesses in the Adelaide CBD installed as part of a pilot smart water network project that began in 2017.

The meters enable users to monitor water use almost in real-time – and as the saying goes, what gets measured can be managed. So, for example, spikes in water use can be quickly spotted, like if an automated irrigation system is left on longer than it needs to. It can also potentially reveal a new leak in the system, which allows for rapid reporting and fixing, saving water from going to waste.

The meters are also being trialled for 310 residential and business customers in Penneshaw on Kangaroo Island, 10 at schools participating in the Smart Water Smart Schools program, and 310 across 190 commercial and industrial businesses in metropolitan and regional areas including three Westfield shopping centres, Adelaide Zoo, Monarto Zoo, Adelaide Oval, Adelaide Airport, Nyrstar and OneSteel.

“It helps businesses and also us to understand the trends [with water use],” the spokesperson said.

The data can be used to fine tune supply, such as adjusting flow rates to specific locations or facilities. It also assists with long term planning for supply and management.

Demand response is also being explored, with smart meters used by wine growers in the Clare Valley allowing the water authority to request irrigation timing to be changed to reduce loss from evaporation during hot weather periods.

Smart meter technology is just one of the remote sensing technologies being explored for water management around the country. Acoustic sensors were installed within the Adelaide network in 2017 and these have resulted in substantial improvements in leak detection and reduced operational costs.

Sydney wants a piece of the sensing action

Now SA Water is collaborating with Sydney Water, researchers and the NSW Smart Sensing Network on a $3 million project to test their use in Sydney.

Forty acoustic sensors have been deployed within the Sydney Water CBD network. The sensors can “hear” the difference in the sounds within the water system when a leak occurs and report the issue and its location to water system managers.

“Water main leaks and breaks are not unique to any state or utility. Maintaining an underground network presents operational challenges which are compounded by environmental factors such as rainfall and soil conditions, and it’s difficult to predict when and where a fault might occur,” Sydney Water customer hub manager Darren Cash said in a media statement.

Dry soil caused by the drought has also been worsening water main breaks.

The acoustic sensors will monitor the water network within an area of approximately 13 square kilometres and the data is being captured and transmitted daily to SA Water’s analytics platform for analysis and investigation.

“Deploying our sensors throughout Sydney’s CBD water network provides the chance to increase the range of data we have to baseline acoustic patterns against, and further fine tune the algorithms we have developed to monitor the data gathered from our Adelaide CBD network,” SA Water general manager of asset operations and delivery Mark Gobbie said.

By combining technology, innovation and capital investment, we’re demonstrating a positive impact on our water network’s performance and forging a new path for asset management.”

Recycled water

In SA, there is an increasing push for every drop to do double duty. Recycled water is being used for multiple purposes including the irrigation of Adelaide Oval. Purple pipe systems are also used to provide water for parks and community sports grounds.

Connection to approved recycled water schemes or recycled water systems are also an option for meeting the state’s mandatory requirement for all new dwellings, or substantial extensions to have a second water source in addition to the mains potable supply.

Rainwater tanks

Where rainwater tanks are chosen as the second source for SA residential properties, they must be plumbed to something useful such as garden irrigation, the water heater, toilet flushing and laundry.

By contrast, in Queensland and Western Australia, tanks are mostly optional for properties connected to mains water and there are no firm rules around what the water must be used for, only guidelines. Queensland has also backpedalled on requirements for rainwater tanks to be installed for major renovations or extensions.

BASIX an ally, but some folk are suss of rainwater

In New South Wales, BASIX assessor Peter Waller says it has been “almost impossible” to achieve BASIX certification for a new Class 1 dwelling unless a rainwater tank is installed.

Where severe space constraints exist, such as in a townhouse development with minimum outdoor space, designs need to implement a work-around such as specifying tapware and showerheads that carry a WELS rating higher than the minimum required by the National Construction Code.

However, just because a home is going to have a tank does not mean the water will substitute potable drinking water. Waller says some clients resist having tanks plumbed to toilets or laundries out of misplaced concerns around potential health risks. You heard it here first – some folk think rainwater is somehow too unclean for flushing toilets with.

Others have concerns it might somehow stain the porcelain.

For multi-residential developments, where meeting the demand for flushing, laundry and landscaping for every residence is extremely hard to do with rainwater, Waller says there are other ways of earning the required BASIX points such as including high-efficiency washing machines and dishwashers as part of the fitout.

Within BASIX, there are also some water saving moves that earn extra points, such as planning low-water landscaping or having a cover installed for pools. Other things cost points – a heated pool for example loses points because heating the water increases evaporation and therefore increases the amount of water needed for top-ups.

Waller says that while the BASIX ratings have helped improve water efficiency, there are still a lot of people who waste water.

“It is still relatively cheap [in New South Wales] and it is always there.”

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