Sign advising of reclaimed irrigation water in use

SAVING WATER: Our series on saving water will continue all summer and finalise with a special report rounding up all our articles and resources.

Perth’s water managers have declared that the city will be a leading “waterwise” city by 2030 but there is a lot of work to do to reach that goal, given that Perth has the second-highest per capita water consumption of any Australian capital city.

Other unflattering statistics include that 42 per cent of Perth’s drinking water is used to water lawns and gardens every year; nearly half of its drinking water supply comes from desalination, and; it has the most energy-intensive water supply in Australia, nearly 2.5 times the next highest energy guzzler.

On top of that, Perth has the second-lowest amount of water recycling of any major urban centre in mainland Australia

It’s unlikely anyone would be willing to say that these statistics lay the foundation for a waterwise city.

At the same time, Perth continues its relentless urban sprawl both north and south, now covering nearly 6,500 square kilometres.

When it comes to watering Perth’s public open spaces, parks and gardens,  local councils have typically relied on the Swan Coastal Plain’s aquifers to meet this demand.

But for decades these have been in decline, both in terms of quality and quantity, and the future for new residential developments is grim.

According to the government, “more than 80 per cent of land identified for urban development by 2030 is in areas with no available groundwater of suitable quality”. Will Perth’s future parks and gardens be irrigated by desalinated seawater?

It begs the question, how much work needs to be done, and at what cost, to turn Perth into a leading waterwise city within the space of 10 years? 

The answer on both accounts is clearly  – a lot! Perth’s residents already pay dearly for water and sewerage, with the second highest bills among Australia’s capital cities. Residents won’t be happy about paying more.

At the Greywater and Wastewater Industry Group (GWIG), we believe the answer lies not in providing more drinking water but instead providing fit-for-purpose water. Fit-for-purpose means matching the demand with the lowest quality source of water that can satisfactorily service that demand whilst still meeting the necessary public health and environmental standards. 

For this reason, fit-for-purpose water is typically the most energy-efficient, locally available, environmentally appropriate and cheapest alternative to drinking water in nearly all circumstances. 

Fit-for-purpose water (also known as non-potable water) explicitly means avoiding the use of drinking water for demands other than drinking. For example, 58 per cent of all Perth’s residential water demand – currently met with drinking water – could be met with fit-for-purpose alternatives (gardens, toilets and washing machines). 

GWIG believes five key issues need to be addressed if Perth is to change its trajectory. These are:

  1. Government action to financially support fit-for-purpose water schemes across all the various scales (i.e., from single-residential plumbed rainwater and greywater reuse; to cluster-scale urban, municipal and industrial wastewater recycling; and district-scale third pipe schemes).
  2. Government action to support and implement the Economic Regulation Authority’s (ERA) report of 2017, which recommended changes to the water and wastewater tariffs in WA.
  3. Government to mandate all new housing be ‘greywater and rainwater ready’ as was proposed for introduction in 2008 as the Five Star Plus Stage 2 program but never enacted.
  4. Government to ensure low carbon-intensity water sources (drinking and non-drinking) are weighted preferentially in the cost-benefit analysis of any proposed schemes.
  5. Government to resource all initiatives that help it achieve its announced water recycling targets in addition to regular annual monitoring and reporting on progress.

This may just sound like more industry bleating about government inaction but all five of these issues demand government leadership. Industry, local councils and many concerned householders over the past 20 years have attempted to get fit-for-purpose schemes of all different shapes and sizes up and running in Perth, but to no avail.

What’s blocking change?

Perth has a poor track record when it comes to large-scale recycled water projects. The path is littered with many great scheme proposals that never got off the drawing board despite millions of dollars in funding. 

Both the Wungong and Alkimos projects were sound, large scale, developer-driven third pipe proposals for residential areas that had the rug pulled from under them at the eleventh hour – with over $35 million in federal government funding embarrassingly having to be returned to Canberra. 

The water consulting industry in Perth is still smarting from these and many other innovative water recycling proposals that have should have been up and running by now.

Needless to say, water for irrigation continues to be a major issue in Perth’s ever-expanding southeast and northwest land development corridors because the problem was never resolved. 

For the recycled wastewater industry in Perth the barriers are many and varied. A report prepared by ACIL Allen in 2016 for Water West – one of WA’s few private sector water and wastewater service providers – articulated many of these. 

It then went on to demonstrate, among many other benefits, how substantial savings in state government capital expenditure could be achieved through the implementation of local wastewater recycling schemes. It fell on deaf ears.


The current water and wastewater tariffs in WA have a lot to answer for, not unlike the situation in Sydney. From a residential perspective, it is not uncommon for the fixed supply charge for water to make up over 70 per cent of the average household bill. This situation has the effect of discouraging water saving as the financial benefit to the householder for being water efficient is miniscule. 

The wastewater tariff component provides no incentive whatsoever as it is based on a percentage of the gross rental value (GRV) of the property.  A 2017 WA Economic Regulation Authority (ERA) report into the costs and tariffs of WA’s three main water utilities said GRVs introduced “perverse geographic distortions, whereby new developments on the fringes of Perth pay less than the cost of providing wastewater services, whereas more expensive inner-city suburbs pay more”. 

“This creates an impediment to the development of innovative, low cost water recycling schemes in new housing estates, where they can be most cost-effective.”

The report recommended a volumetric tariff for residential wastewater (one already exists for industry) be introduced, perhaps along the lines of the Victorian model. Needless to say, this also fell on deaf ears – the Government’s. It is also worth noting that work done at UWA demonstrated that ERA’s recommendations would achieve improved social equity at the same time. 

Money speaks

So why is the state government, irrespective of political hue, so reluctant to push water reform and promote innovation in the private water space? It would appear that no water minister is prepared to kill the goose that lays the golden egg. 

Since corporatisation in 1996, the Water Corporation has been owned by the government. In recent years, as outlined in its annual reports, the corporation has typically paid a dividend to government of half a billion dollars, annually.

GWIG has not been able to confidently ascertain the current wastewater recycling data upon which progress towards the state’s targets can be assessed. Based on our research, it would appear, quite remarkably, that neither the Water Corporation, Department of Water and Environment, ERA (stopped in 2018), or BoM National Performance report provide statistics for the percentage of wastewater that is recycled. 

Nor are the targets particularly clear. With regard to Perth’s water recycling target, it would appear that it has very recently been increased to 45 per cent. But 45 per cent of what? Is it 45% of the projected demand-supply gap for the city in 2030 (Water for Life, Waterwise City) or is it 45% of all wastewater as some commentators not unreasonably seem to think? 

It is not clear what the difference is volumetrically between these two definitions of 45 per cent and the previous definition of 30 per cent by 2030 Water Corp target

When did the goal posts get moved, and by whom? Who is responsible for achieving them? Who will be blamed if they aren’t met?  Bear in mind that Perth missed its 20 per cent by 2012 Department of Water target by a country mile (an average of 7.5% between 2012 and 2017).

So, with Perth’s third desal plant earmarked to go ahead at Alkimos – the site that could have been a shining light for WA’s fledgling recycled water industry – you could be forgiven for thinking that all is not right in our great state when it comes to water recycling.

Stewart Dallas is a founding member and Chair of the WA Greywater and Wastewater Industry Group (GWIG). He is a qualified civil engineer and has a PhD in the field of Ecological Engineering.

Spinifex is an opinion column open to all our readers. We require 700+ words on issues related to sustainability especially in the built environment and in business. For a more detailed brief please send an email to

Leave a comment

Your email address will not be published. Required fields are marked *