Momentum grows for diversified water supplies

As the global population continually grows and a changing climate brings highly variable rainfall, pressure is building – both locally and internationally – to secure more reliable water supplies.

The University of Melbourne’s April Water Security Series considered the question of whether our cities are ready for diversified water supplies.

The conclusion from panellists taking part in the webinar discussion was that now is the time to advance this idea towards broader implementation.

Closeup of stormwater drain with water flowing into it
Drawing water from stormwater will help cities' water security while reducing pollution in our rivers

If adopted, drawing water from a wider range of sources, including storm and waste streams, will not only help secure future needs for our cities but will also reduce pollution in our rivers.

Recycled water is already used in Perth in Western Australia, California in the USA and Singapore. In the wake of widespread drought in Australia, panellists said the time is right to engage the community and governments in expanding diversified water supply initiatives.

Demand from freshwater catchments could be halved in a diversified system, said Associate Professor Meenakshi Arora, Assistant Dean International at Melbourne School of Engineering.

Flushing toilets, laundry facilities and watering open spaces could all use treated recycled wastewater or stormwater.

“And if we take it a step further and treat our wastewater to a potable standard [for human consumption] we can reduce the freshwater demand even further,” Associate Professor Arora said.

Closeup of orange flowers with blurred iron fence and taxi in background
Water is essential for greening and cooling urban spaces

Diversified supplies could also help underpin the liveability of our cities, explained Stuart Wilson, Deputy Executive Director of Water Services Association of Australia.

Wilson outline the essential role of water in greening and cooling urban spaces and promoting the better health of residents. The need to supply water for this purpose has not been recognised in water planning considerations in the past, when rainfall was more plentiful.

But in a changing climate, diverse water sources such as desalination, rainwater tanks and recycled water will be key to maintaining greener urban environments on a broader scale.

Circular supply systems

The need for a more diverse supply mix was also recognised in regional cities according to David Sheehan, Senior Water Quality and Regulatory Advisor at Coliban Water, which services Victoria’s “climate hotspot” of Bendigo and surrounds.

Traditional linear models of water delivery with a dam at one end and disposal at the other needed to be transformed into more circular systems to “future-proof” water supply

Sheehan commented that traditional linear models of water delivery with a dam at one end and disposal at the other needed to be transformed into more circular systems to “future-proof” water supply.

Water utilities are up for the technical and operational challenge to deliver a diversified water supply. However, panellists agreed better collaboration was needed to overcome attitudinal, bureaucratic and funding barriers to what is a significant cultural change.

This is because water utilities don’t control all the levers of diversifying supply, including consumer acceptance.

On the supply side, collaboration is needed with local councils to integrate wastewater and stormwater, while on the planning side, industry also needs to work with state governments and developers on water cycle management to improve urban liveability.

Water planning

Water needs to be integrated into the whole planning system, in the same way as other core infrastructures, such as health and transport.

“The water industry needs a seat at the planning table,” Mr Wilson said.

This kind of recognition within the broader planning process for liveable cities would provide the water industry with direct access to government funding for ‘green’ and ‘blue’ initiatives.

Associate Professor Arora outlined how cost-benefit analysis that takes into account the environmental costs of inaction would further the case for change.

We only have a finite supply of fresh water. We can’t just continue with business as usual

Research will be critical to both technological advances and setting policy in the right direction.

Implementing new systems with multiple end users would be complex, said Associate Professor Arora, but change would be necessary.

“The world population is growing, and so is water demand. And we only have a finite supply of fresh water. We can’t just continue with business as usual.”

COVID-19 wastewater surveillance will be the topic of the next webinar in the Water Security Series on Wednesday 13 May from 12pm to 1pm. Register via Eventbrite

Related topics

Water security Water, Environment and Agriculture Program

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