INFRASTRUCTURE Victoria have recently released their draft 30-year infrastructure strategy, with recommendations for the expansion of the desalination plant in Wonthaggi, which has operated sporadically over the past 13 years.
With climate change expected to create warmer and drier conditions leading to less available fresh water, Infrastructure Victoria (IV) have reported that up to 65% of Melbourne’s water might need to be from manufactured sources by 2050.
This is an increase from 2020, when 25% of Melbourne’s water was desalinated and 10% was recycled.
“Manufactured water facilities can take up to 10 years to plan and build. Preparing now means that more water will be available when Victorians need it,” the report states.
“This can come from a new desalination plant or recycled drinking water facility.”
The Victorian Desalination Plant was built in 2012 following 13 consecutive years of drought, at a cost of $3.5 billion, to build, which was said to have blown out to $6 billion.
It is the largest desalination plant in Australia, and in nominal terms over its 30-year contract – which is set to expire in 2039, the estimated cost to repay, maintain and operate the plant is nearly $24 billion, approximately $700 million annually.
This cost is paid by the state and Melbourne Water users – whether or not the plant operates – adding roughly $421 to a Melbourne family's water bill (each year for 30 years).
The plant has been designed so that it can be expanded when Melbourne needs more drinking water and can deliver up to 150 gigalitres (GL) annually.
However, by the time the plant was finished in 2012, the drought was over, and Victoria experienced floods, seeing water reserves fill to overflowing across the state.
The first water order from the plant wasn’t made until 2016. There were then orders for subsequent years, up to 2022, however often only for minimal amounts, of 15GL to be delivered.
The plant has operated for only seven of the 13 years it’s been available and delivered only 455GL of water from a possible 1950GL, well below its capacity.
“The Victorian Government should plan for and invest in other manufactured water sources before Victoria needs more drinking water,” state IV in their draft strategy.
“The Victorian Government should develop a business case that considers expanding the plant.”
Given the intermittent and minimal usage of the current desalination plant, together with the staggering cost to repay, maintain and operate it, these recommendations to the Victorian Government from Infrastructure Victoria are questionable.
The estimated cost of feasibility studies and developing business cases alone, to allow for further water projects to start construction by 2035, is estimated to cost between $1 million to $5 million.
IV state simply that the general government revenue and user costs collected by water authorities can fund this future option.
IV do make it clear that the millions for planning does not also include the cost of actually going ahead with any of their recommended projects.
“We estimate that building manufactured water projects will cost in the billions of dollars.”
IV state on page two of their strategy: Infrastructure Victoria does not directly oversee or fund infrastructure projects.
