Why Melbourne Needed Water Recycling

Smarter Urban Water: Why Melbourne Needed to Catch and Store

Greywater and stormwater recycling are part of a holistic policy needed to deal with drought in an increasingly harsher climate

Two blue glass boxes rise from the grass next to the Melbourne Cricket Ground. If you glance at them - on your way to an Aussie rules game, of course - you'll notice some pipes inside.

Nothing special, really. It's only a sewer mine . Or, as the officials prefer: theYarra Park Water Recycling Facility.

Below ground, a large pipe snakes uphill, avoiding tree roots. It taps into the main vein below the snooty suburb of East Melbourne, and sneaks off with its sewage.

In summer, the large parklands around the ground are irrigated entirely with recycled water from the facility. In the winter, it flushes the toilets of tens of thousands of spectators each weekend.

The facility supplies cheaper water than the gigantic Victorian desalination plant, which was built with considerable cost and controversy 100km south-east of the city. Both were completed in 2012. But the desalination plant, unlike the sewer mine, has never produced a drop.

Something strange and remarkable has happened in Melbourne. Five years ago, the city of over 4 million inhabitants nearly ran out of water. Now it is regarded among the most innovative, water-smart cities in the world.

From 1997 to 2009 southern Australia suffered through the "millennium drought", its longest dry spell on record. "The drought was a huge wake-up call," says Dr Cathy Wilkinson, an executive director at theOffice for Living Victoria, the government body now in charge of water policy. "The way water was managed had a huge impact on people every day. Waterways were drying up, junior sports clubs couldn't play on their ovals because they were too dry and dangerous."

Southern Australia faced its longest known severe drought between 1997 and 2009. Here sheep graze on on the dried-up Lake George near Canberra. Photograph: Lukas Coch/AP Image

In panic, the then Labor government ordered a mammothdesalination plant- with a top capacity of half the city's water consumption - and a pipeline to bring water from the north of the state.

It also issued tight water restrictions. Newspapers reported on neighbourhoodwater vigilantes; people using rainwater tanks feared being seen with green lawns. Water consumption dropped 40%, per person per day. Without that shift, drinking water supplies would have run out.

The imminent threat concentrated minds elsewhere. Local councils, unable to water outdoor space, began to seek alternatives.

Prof Ana Deletic, associate dean of engineering at Monash University, explains that research flourished, especially into reclaiming stormwater - the polluted rainfall that flows off roads and car parks, into the bay.

"The same amount of runoff goes into Port Phillip Bay as we use in Melbourne each year," she says. "We were talking about how we could capture some of that water and reuse it, but also save our streams in the process."

The university now hosts theCooperative Research Centre for Water Sensitive Cities, which has over 70 researchers and a budget of over $100m. It's a multi-disciplinary body, with programmes looking at social drivers, planning, technology and, importantly, how to get it all adopted in real life.

Video: CRC For Water Sensitive Cities

Deletic's speciality is green walls that treat greywater: the system where plants recycle greywater, filtering out pollutants and using them as nutrients for growth. "It's a technology that cools your city, makes it beautiful but also produces water," she says.

Enter a conservative state government in 2010. It mothballed the desalination plant and the pipeline and established the Office of Living Victoria, with a holistic mandate - much like what the academics had ordered.

Wilkinson says that, historically, water planners sought to predict and provide. The city was a drain; waterways just pipes to the bay.

Now the vision is decentralisation. Catch and store water where it falls. Treat stormwater and wastewater locally, where possible, and reuse it to irrigate parks and gardens. Use drinking water for drinking, not for everything.

"When we do our long-term water planning, we need to think about the complete range of sources, and match the right water for the right job," Wilkinson says. "At its heart it's about how Victoria can be resilient and liveable in the face of a whole heap of changes that are going to happen."

Source: The Guardian

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• Water Reuse & Recycling
• Environment