Desalination & Reuse Handbook - Flipbook - Page 17
THE YEAR IN SCARCITY
Tariffs
Perth (Australia)
Despite the steadily increasing cost of Perth’s water, the
city’s consumption is the highest of any major Australian
city. Perth’s water was the most expensive of any major
Australian city, with average consumption one and a half
times that of the second most expensive, Melbourne.
Half of Perth’s drinking water now comes from relatively
expensive SWRO, and it seems residents are prepared to
pick up the bill.
Legend
Fixed charges per month
Water: $15.88 Wastewater: $68.90
Sales tax
Water: 0
Wastewater: 0
Volumetric charges: increasing
Water: Block (m3)
0.0-12.5
12.5-41.7
>41.7
$/m3
1.32
1.75
3.28
Benchmark tariff (15 m3/month)
Fixed water costs
Fixed wastewater costs
$7.04/m³
Variable water costs
1.06
1.39
4.59
Source: Global Water Leaders Group
Perth was the first Australian city to make large-scale use of seawater reverse osmosis (SWRO) to supply its water needs.
With a combined capacity of 240,000 m3/d, the city’s two major SWRO plants provide around its fresh water and the
technology forms an essential element of the city’s long-term, water security planning. Following Perth’s example, Sydney,
Melbourne, and Gold Coast have all built their own desalination plants, with Californian observers citing the city as
demonstrating a relatively cost-effective application of desalination technology on a large scale (avg. $1.22/m3).
To meet much of the remaining 40% demand (as of 2018) WCWA is developing its deep groundwater network to exploit
aquifers far beneath the surface. The superficial aquifer, previously one of Perth’s primary water sources, now provides
only 10% of the city’s water.
Alongside deeper extraction, WCWA has initiated a water recycling and Groundwater Replenishment Scheme, drawing
on the example of Orange County, California, where recycled water has recharged aquifers since 2008. Water recycling
for potable use has not always enjoyed popular support, but after eight years of public engagement and successful trials
between 2010–12, work has begun to increase Perth’s potable recycled water supply. By mid-2019, Perth will be capable
of recycling 28 million m3 of water for potable use each year, recharging aquifers with enough water to supply 9% of the
city. WA’s Government has committed AUD262 million ($189 million) of funding to water recycling development, aiming
to recycle 115 million m3/yr of wastewater for mixed uses by 2060. WCWA aims to recycle 60% of Perth’s wastewater for
potable aquifer recharge by then, protecting vulnerable surface ecosystems and insulating Perth’s groundwater supply
from depleted rainfall.
These plans are not without their problems. The city’s new-found dependence on SWRO brings with it the unavoidable
irony that, such are these plants’ energy demands, they risk contributing to anthropocentric climate change even as they
work to mitigate its effects. To offset some of these concerns, in 2011 WCWA purchased 100% of the energy output
from the Greenough River Solar Farm and Mumbida wind farm, developed at a combined cost of AUD200 million
($144 million) and supplying 65 MW of power to the Western Power grid.
Tariffs and Usage
Key numbers
Desalination and Reuse
Reductions
50% sourced from
seawater desalination (2016/17)
1 amongst Australian
st
cities for cost of water
223 m3/yr of water
supplied per property 32% above nationwide
average for major utilities
19% reduction in
water use 2007-2017
15%
2030 target for water usage
reduction
8 years of public
engagement before building
groundwater recharge capacity
60% target for wastewater
used in aquifer recharge by 2060
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