Can desalination quench Adelaide’s thirst?

Cerys writes*

Adelaide has always had problems with water security, ever since its establishment by British settlers in 1836. In the mid-19th century the growing population came to the realisation that the small Torrens River couldn’t fulfil Adelaide’s rapidly growing demand for water. Although reservoirs were built, Adelaide’s water supply still couldn’t cope with the increasing demand. So in 1955 Adelaide started to pipe in water from the Murray River (over 60 kilometres away), but this was a temporary solution.

The use of the Murray River has now become a source of contention and Adelaide is once again on the search for a new, sustainable source of water. In 2012 the South Australian government constructed a AU$1.83 billion-dollar (€1.18 billion) desalinisation plant in Lonsdale, just south of the city. It has the capacity to produce 100GL of clean water per year. In 2019 the South Australian government decided to increase water production at the desalination plant to 40GL of water per year in aid of drought relief. This figure may rise to 60GL in 2021.

Photo source.

Although this may seem like a solution to water scarcity, this plan has three large problems;

  1. The plant doesn’t have the capability to produce enough water to satisfy Adelaide’s water demand. At the moment Adelaide’s desalination plant supplies around 4% of Adelaide’s water demand, but even if the plant is running at maximum capacity (100GL per year), this would only satisfy half of Adelaide’s water demand. Therefore, Adelaide will be forced to continue using unsustainable, alternative water sources such as the Murray River.
  2. Desalination is expensive! According to SA Water’s 2016 report, water costs AU$0.95/m3 (€0.61) to produce in Adelaide’s desalination plant. This is more than 9 times the global average for ground water extraction. Because of this, the South Australian government is unwilling to make desalination the main source of water in Adelaide because it’s economically unsustainable.
  3. Desalination has negative environmental impacts. Desalination plants require the burning of fossil fuels for energy, and they produce brine as a by-product that may harm marine organisms and coastal water quality. Since the negative environmental impacts of water extraction from the Murray River is one of the reasons why Adelaide wants to reduce its reliance on the Murray, it doesn’t make any sense to switch to desalination instead, as that also damages the environment.

Adelaide will not be able to rely on desalination to quench its increasing thirst, so What’s the solution? Should they focus on recycling waste water or fixing leaks or lowering demand through price increases? In reality, this question is very difficult to answer and I’m sure that if there was one simple solution, Australia would already be doing it.

Bottom Line: Desalinisation is not a permanent solution to Adeaide’s water scarcity.

* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Author: David Zetland

I'm a political-economist from California who now lives in Amsterdam.

4 thoughts on “Can desalination quench Adelaide’s thirst?”

  1. Hi Cerys, this is an interesting case! As you mentioned, there is not a straightforward solution and it will probably be a mix of the three strategies that you reported that will create a sustainable supply of water for Adelaide. We did not discuss desalination’s process and effects in depth in class (yet), but I read from this UNEP article ( that its environmental impact should not be neglected. The disposal of the toxic brine has impact on the marine ecosystems and that obviously impact humans food chain as well. Considering that per each liter of freshwater produced through desalination, 1.5 l of toxic liquid comes as a waste product, we can agree that desalination should be used as last resort for freshwater supply. However, how much “worse” would the impact of desalination be compared to the depletion of the Murray river? Such questions are wicked in nature, but if answered through appropriate technical assessment, they could provide a solution for Adelaide and many other cities which are currently short on water…

    1. Hi!
      You leave a very valid point in; are the negative environmental consequences of desalination worse than extracting from the river. This is a very hard question to answer since the environmental impacts of both, are hard to quantify.
      Something that wasn’t mentioned in this blog was the fact Adelaide and the whole of the state of South Australia extracts only a small fraction of the total extracted water from the Murray River. Therefore, I think that the movement from river water to desalination will not necessarily save the Murray either. This will leave us with a double negative result (both a degrading Murray and desalination waste).
      This is why I am emplacing a need for more research and investment into searching for other sustainable methods of supply water and reducing water demand in Adelaide. The best solution to the problem of water scarcity in any place is reducing demand, so that less water has to be produced by desal or pumped in from rivers. That is why it is so important that we do this, so we don’t end up having to settle on the environmental compromise of desalination, which still isn’t particularly environmentally friendly.

  2. I don’t have a particular comment, rather I’d like to spam you with questions because I found your post very interesting and well-written:
    – Is the water managed publicly or is it privately owned? I suppose it might be publicly owned given the extent of governmental involvement in the desalination plant?
    – Are there other plans under way/any alternatives to desalination that are ‘in the shadows’ (perhaps not immediately considered by the government)? how are other nearby cities coping in terms of water scarcity and what can Adelaide learn from them?
    – to what extent do you see the negative environmental factors being taken into consideration, given the current government and administration and its perspectives/ plans with regards to business as usual activities? what is the southern Australian government’s stance on these issues? what kind of solutions are there with regards to the toxicity and very high environmental costs of desalination?

    1. Hi Enrica!
      You are correct about the fact that it is publicly owned. The SA government set up SA Water, which provides water to Adelaide.
      About other plans; there are improvements in storm and waste water recycling plants. This is something that is gradually increasing, however, unfortunately, there is still a stigma that this water isn’t good enough for drinking (which is made worse by the desalination advocators). Unfortunately desalination seems to be growing faster in Australia than recycled water, as seem by the fact that 45% of Perth’s water supply comes from desal!
      The environmental implications of desal don’t seem to be taken into consideration, because of the urgency of the problem and the fact that that desal is seen as just drought relief. Therefore, there is a misconception that this is the only thing that can be done when drought is a problem (which means that nothing is being done to counter balance the negative environmental impacts of desal). This is not surprising when you see Australia’s stance on mining and climate change altogether!

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