Why Do Sydneysiders Use Way More Water Than Melburnians Daily?

It's a difference of about 30 per cent.

Earlier this week Melbourne's water storage dropped below 50 percent, as drought continues to grip Australia's east coast.

A little further north and Sydney isn't fairing much better.

The city's dams are currently sitting at 53.8 per cent capacity. If levels continue to drop the way they have been, the harbour city can expect to dip below 50 per cent in about 10 weeks, at which point restrictions will kick in.

But while Melbourne may have beaten Sydney to the halfway mark, its residents actually use less water per day when compared to their northern neighbours.

Melbourne's average resident consumes 161 litres per person per day, while in 2018, the average Sydney resident used 210 litres -- a difference of about 30 per cent.

Image: Getty

Why? According to  Senior Lecturer in Environmental Science at Western Sydney University Ian Wright, water prices might have a lot to do with it.

"Sydney is using far more water than experts predicted," Wright said in The Conversation.

READ MORE: Water Restrictions May Not Fix Our Drinking Problems This Time

The city's 2017 Metropolitan Water Plan predicted that  by 2018, Sydney would be using around 550 gigalitres per year.

But as Wright points out, the city's actual consumption was 600GL.

A look at historical water usage indicates a sharp rise during 2016 -- the same year water prices in the city fell by just over 13 per cent.

Image: Sydney Water 2017-18 Water Conservation Report.

"Water is far more expensive in Melbourne, which has variable pricing for residential water. The more water you use, the higher the progressive cost per litre," Wright said.

Sydney, on the other hand, charges flat rates -- so it doesn't necessarily pay to use less water.

"With no end to the drought in sight, it may be time for Sydney to learn from Melbourne. Sydney could easily put a higher price on water, with higher users eventually paying more per litre," Wright said.

It's A lot, But A Lot Less Than Before

While Sydney might use more water per resident than Melbourne, the city's water habits have changed dramatically since the Millennium Drought.

The event devastated communities across most of southern Australia between 2000 and 2010. This drought meant numerous water efficiency measures were put in place, from household changes such as more efficient shower heads and toilets to industrial changes.

"We act differently now and we have different infrastructure," said Stuart Khan, a professor in the University of NSW's School of Civil & Environmental Engineering, told 10 daily.

"All of those measures relieved a lot of pressure off the drinking water supply and we never went back."

How much water is used in Greater Sydney. Image: NSW Government

READ MOREHalf Of Sydneysiders Don't Believe City Is In Drought

Each Sydneysider now uses 50 litres less per day than they did before the Millennium Drought.

Staring down the barrel of water restrictions once again, there are concerns the city won't be able to save water the way it did back then.

What we are concerned about is that we've now picked the low-hanging fruit, we've taken those easy steps," Khan said.

"So to be able to save more litres will hurt a lot more."

Featured image: Getty