Desalination & Reuse Handbook - Flipbook - Page 16
IDA
WATER SECURITY
HANDBOOK
PERTH, WESTERN AUSTRALIA
Looking as far as 50 years ahead, Water Corporation of Western Australia’s (WCWA) water security plan is built around
three key elements: reducing water use; securing new, climate independent water sources; and increasing the region’s
water recycling capacity.
Since the 1970s, long-term public engagement has been favoured over potentially inflammatory, reactionary crisis
measures to reduce water consumption. Perth’s water consumption has reduced by more than 19% in the last decade
alone. This was accomplished by encouraging residents to install more efficient appliances, implementing both permanent
and seasonal water use restrictions and introducing gradual tariff increases that made Perth’s water the most expensive
of all Australia’s major cities (18% higher than that of second placed Melbourne). Despite this, Perth’s average water
consumption (127 m3/capita/yr) remains amongst the highest in Australia, with WCWA targeting 15% reduction by 2030.
WA’s rainfall has reduced by 19% and the inflow into Perth’s dam network has fallen significantly over the past 50 years.
On average, only 75.3 million m3/yr flowed into the region’s reservoirs between 2006 and 2010; a drop of more than 100
million m3/yr from 1975–2000 levels. In these circumstances, it was clear that the city’s climate-dependent water sources –
its dams and superficial aquifer – would no long be able to satisfy demand. Continued dependence on these sources risked
shortages and irrevocable damage to local ecosystems.
2011 saw WCWA publish its ‘Water Forever, Whatever the Weather’ pledge to drought-proof Perth. Alongside light-handed
water saving measures, the utility committed to increasing supplies from seawater desalination and water recycling:
climate independent sources that could both satisfy demand and stabilise depleted aquifers.
Volume of water sourced in Perth urban centre (%)
Seawater desalination has all but replaced surface
water abstraction in Perth’s water mix of water sources.
Meanwhile wastewater reuse remains a small part of the
city’s water supply. Public opinion was the key driver
behind the decision by Water Corporation WA to pursue
desalination over wastewater reuse in the late 2000s - the
utility’s two-year construction timetable for groundwater
recharge capacity was preceded by an 8-year PR
campaign to win public support for indirect potable reuse.
100%
80%
60%
40%
20%
0%
2005-06
Surface water
2010-11
2014-15
Groundwater
2015-2016
Desalination
2016-2017
Recycled water
Source: Australian Bureau of Meteorology
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