Adelaide desalination plant: SA Water ignores its own experts to keep it running
SA WATER has ignored a report that reveals for the first time producing desalinated water is far more expensive than sourcing it from the Mt Lofty catchment or the River Murray.
THE ongoing operation of the $1.8 billion Adelaide desalination plant could not be justified financially or environmentally, an independent report has found.
The report also, for the first time, revealed the true cost of producing desalinated water and showed it to be a far more expensive option than sourcing it from the Mt Lofty catchment or the River Murray.
The study was commissioned in December by SA Water to advise on what water sources should be used from now until 2050, comparing all drinking water available to Adelaide from; desalination, the Mt Lofty Ranges catchment, and the River Murray.
But the finding of the report were ignored by SA Water so that it could keep the desalination plant running.
The report, funded by SA Water but carried out by CSIRO scientists, reveals the SA Water decision to continue with the inefficient desalination means house holders will pay $40 million each year to run the unwanted plant at a cost per-litre four times that of other supplies.
Despite finding that desalinated water should not be used except during a handful of dry years, SA Water will run the plant at a minimum volume of water, costing homeowners $10 million each year to produce 10 billion litres of water, plus $30 million each year to maintain the plant.
The study concluded: “The Mount Lofty Ranges catchments are generally the preferred source for potable water supply due to their low cost and energy. Water from the River Murray is generally the second choice for potable use. The desalination plant is used primarily as a backup supply in dry years’’.
“In all scenarios only a small volume of water was drawn from the desalination plant due to its high cost and energy.”
The study compared the performance of all water sources based on three criteria; operational costs of infrastructure, total energy usage, and total discharge of wastewater and stormwater to Gulf St Vincent.
It has only now been released after The Advertiser revealed SA Water’s decision to run the desalination plant despite it not being needed, and at far less capacity than the 100 billion litres it had been designed to produce.
The report also reveals for the first time the high cost of producing desalinated water, despite previous claims by SA Water that this figure had to be kept secret because it was ‘‘commercial-in-confidence”.
House holders pay 23 cents per 1000 litres to make Mt Lofty water fit to drink, 44 cents for River Murray water and $1 for desalinated water. This has led to a doubling of water bills to pay for the $1.8 billion plant and a $400 million pipeline to connect it to the northern suburbs.
Contrary to the SA Water decision to keep the desalination plant running, the independent study could not justify the plant producing any water in most years, and at most 2.9 billion litres in 2050, or 1.4 per cent of demand.
The only measure in which the desalination plant failed to rank last out of all drinking water options was in focus groups made up of members of the public, during which people ranked it second as a source of water in order to help save the Murray.
“The priorities inferred from the focus groups actually had desalinated water ranked ahead of water from the Mt Lofty Ranges, but this was considered to be unreasonable because of the high cost and energy associated with desalination and the fact that it was government policy to use the desalination plant as an emergency source in droughts,’’ the report states.
Inquiries by The Advertiser have revealed the reason SA Water chose to ignore the findings of the report was because desalination plant maintenance costs of $30m each year do not change no matter whether it is producing water or not.
When asked why SA Water had chosen to ignore the findings of the report a spokeswoman stated: “The decision to operate the Desalination plant at minimum capacity for 9 months of the year through to June 2016 was made after comparison of operating at this level and not operating at all. The comparison showed that the cost to operate under the two scenarios was effectively the same’’.