A Review of Our Water Security

How Population Growth Threatens Our Water Security and Sustainability

In November, 2024, Sustainable Population Australia released it’s discussion paper on Australia’s water security, authored by Jonathan Sobels, Peter Cook, Sandra Kanck and Jane O’Sullivan. Water is crucial to sustainable growth on this driest inhabited continent, so I decided to read it with a fine-toothed comb and a critical eye. This review is limited to points I thought worth highlighting; the full report is much more comprehensive. Full disclosure; I am a Queensland state branch committee member of SPA. However, I am also a member of Queensland Skeptics, so I took to the report with the critics in mind who usually accuse SPA of being unduly pessimistic.

NO MORE DAMS

In most places, more dams are out of the question due to declining streamflow and lack of
suitable sites. The alternatives are referred to as ‘manufactured water’, including desalination and
recycled water.

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I recall the Queensland Mary River dam proposal that was overturned and PM Tony Abbott’s call for more dams across the country. However, proof that more dams are unlikely is in the fact that since the turn of the century, expensive, complex alternatives have already been resorted to; desalination plants. Beginning with Perth in 2006, Melbourne, Adelaide, Sydney and Brisbane followed suit. Australia’s urban water demand had reached the maximum that could be supplied reliably by conventional means. In other words, we passed the local hydrological carrying capacity.

Climate change is altering the hydrological system across the continent, reducing rainfall in dam catchments for the major population centres and increasingly,

More generally, dams are far less able to supply water in our warming, drying climate. Every 1%
less rainfall causes approximately 3% less runoff.

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This information comes from the Journal of Hydrology: Regional Studies and BOM (Bureau of Meteorology)

MEGA PROJECT SOLUTIONS

Australia is wet in the north for most of the year, while the centre is bone dry and most of us live in the south east. Mega projects have been envisaged that deliver that water close to where it’s needed, such as the Heihsel proposal to replenish the Murray-Darling Basin using 5,500 GL per year of desalinated seawater from 29 coastal plants. Or the Bradfield scheme, towing icebergs from Antarctica, or pumping water from Lake Argyle in the Kimberley to provide fresh water for our southern cities. Although these projects look feasible on paper, the problem is the cost, not to mention the environmental impact. Perhaps that is why some of them are not costed properly at all. It really begs the question, why try so hard for the sake of a bigger population? One of my favorite YouTube bloggers is the Czech techno-optimist debunker Adam Something. His ‘Dubai is a Parody of the 21st Century‘ is a classic. Australia doesn’t have the uber wealthy dictators the Middle East does, so we’re spared their craziest brain farts as explained at 08:45 in ‘Dubai’s $5 Billion Lunatic Megaproject‘. A consultant reached out to him to share his first hand experience of working on these project for them saying, “these leaders have very short attention spans”. But I digress.

The report doesn’t mention how humanity has burst free of the confines of our planet and is talking of sourcing resources off-world. This is relevant to minerals rather than water, but I think it’s worth keeping in mind that ‘limits to growth on a finite planet’ ignores the progress into space we’ve made. An acknowledgement that we’re not going to find water in space (that’s useful for Earth) is helpfully grounding to the techno-optimists. A bit like reminding them that it’s easier to colonize the Sahara or the Simpson deserts than Mars.

PERTH

Perth stands out as a city exceptionally vulnerable to water shortage, heat and drought (page 23 Figure 8). Few people realize it’s further north than Sydney and highly dependent on ground water (page 19 Figure 6 & page 20). Temperatures there have been remarkable in recent years.

HUMAN WATER USE OVER TIME

Agriculture is by far the biggest user of water at between 60% and 70% of the total… In 2020-21, which was a wetter year, agricultural use was 69% of total water use, followed by manufacturing and mining (19%) and domestic use (12%).

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The report is frank about positive statistics:

Since 1977 Australia’s population has doubled, but aggregate water use has slightly reduced,
largely due to increased regulation of irrigation in the Murray-Darling Basin. Despite population growth, total water use by the household sector has remained fairly stable, accommodated by increasing efficiency of water use within households and less watering of gardens.

_{Page 18 Source: ABS Water Accounts; Klaassen, B. (1981)}

This increasing household sector efficiency has been driven by several factors: temporary water restrictions introduced during drought, educational and involvement campaigns to encourage less water use, increases in the price of water, new water efficiency labeling on appliances, changes in building codes and changes in the housing stock to smaller blocks, higher densities and reduced garden size.

_{Page 18. Source: Horne, J. (2020). Water demand reduction to help meet SDG 6: learning from major Australian cities. International Journal of Water Resources Development, 36(6), 888-908}

In other words, we are sacrificing lifestyle for population growth and in doing so, exposing urban populations to ever greater dependence on systems that deliver essential supplies which are becoming more vulnerable to disruption due to climate change and geopolitical tensions. Furthermore, once densification takes hold, the scope for greater efficiency shrinks. The Greater Melbourne Urban Water & System Strategy says, “ongoing urban densification will lead to less external water use as gardens diminish in size, further reducing the effectiveness of water restrictions.” (Melbourne Water (2023) Greater Melbourne urban water and system strategy: water for life, p. 104)

Human use of water over the past two thousand years shows that recently we have been living in relatively lucky times. Paleoclimate research has added data indicating that the twentieth century has had comparatively fewer and shorter droughts despite global warming (see sources on page 29). It is concerning that during non-drought periods we have been experiencing increasing temperatures and lowered (and more variable – flooding) rainfall.

COMMODIFICATION OF WATER

The report lifts a veil on an oft-overlooked development that technology introduces; the commercialization of once cheaply accessed freshwater. Desalination brings with it complexity, dependencies and costs that are passed on to a community that it wasn’t previously burdened with.

In looking at the relative typical costs of water supply options, I was surprised to see (Figure 13, page 43) that rainwater tanks are the second most expensive. I believe this has to do with economies of scale.

From personal experience, having installed a $10,000 rainwater harvesting system in my suburban home, I can attest to its expense and complexity. However, it paid itself off after 10 years and has since distanced my finances from the commercial system. It has contributed to alleviating the town water system of my household’s demand (without reward from the Council). However, in my particular circumstances, the need for onsite water pressure pumping has added to complexity and expense that is integrated in the town water supply. During Covid, the pump’s O-ring blew out and it took 3 months to get a replacement. A rain harvesting system is less complex than an electricity generating photovoltaic rooftop system, and yet many of us see these distributed systems as a liberating step forward.

The report makes the very good point that with a smaller population and lower demand, we can return to regarding water as a commons. We can return to relying on simpler, cheaper, large-scale systems that are more reliable.

URBAN TREE CANOPY

As little as seventy years ago our cities were barren of street trees. Today they’re everywhere and they help reduce the heat island effect of hard, impervious, often dark surfaces that cities and suburbs are made of. As our cities have grown, vegetation has given way to suburbs that have given way to high-rises. The report states that the urban tree canopy can increase the demand for water. It cites the Productivity Commission; a 20% increase in urban tree canopy in Adelaide could potentially require an additional 10% to 30% of Adelaide’s current water demand (page 28). Although the report doesn’t explain this, apparently in some cities trees need watering beyond the establishment phase. I couldn’t help feeling that without weighing up the cost of this investment with the benefits in both a growth and a steady state scenario, the narrow focus on water consumption is dogmatic.

WHOLE SYSTEMS THINKING

I love it when people cut through bullshit. The authors do this by pointing out how authorities get themselves bogged down in details in an attempt to avoid the fact that technology won’t save us.

They seek to move away from sectoral silos towards multi-sectoral and multi-scale approaches to planning, as well as greater community participation and co-design of solutions. All of these initiatives infer greater government intervention to facilitate, educate, coordinate and regulate – meaning added layers of complexity. This doesn’t make them bad ideas, but when little is achieved beyond wider consultation and theorising on whole-systems thinking, it becomes a form of self-delusion to think that solutions are simply waiting to be uncovered, rather than admitting we have a wicked problem.

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CULTURE

The report opens with the full text of Dorothea MacKellar’s poem I Love a Sunburnt Country, the first verse of which I have never heard of. In fact, it’s called My Country, but it was titled Core of My Heart when published in September 1908 as Australia’s 4.2 million people emerged from the hot-as-hell Federation Drought. I want to replicate it in full here, because as the authors say, “it dramatically contrasts the bucolic ideal of England’s mild climate, plentiful water, green vistas and rich soils with their Australian antithesis.”

The love of field and coppice,
Of green and shaded lanes.
Of ordered woods and gardens
Is running in your veins,
Strong love of grey-blue distance
Brown streams and soft dim skies
I know but cannot share it,
My love is otherwise.

I love a sunburnt country,
A land of sweeping plains,
Of ragged mountain ranges,
Of droughts and flooding rains.
I love her far horizons,
I love her jewel-sea,
Her beauty and her terror –
The wide brown land for me!

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The authors display a deep appreciation for Australia’s environment and its people. Their report is brilliantly eloquent and yet accessible to the lay person. I thoroughly recommend taking the time to read it.

If there was one thing Dorothea MacKellar missed it’s our azure skies; a blessing that comes with the Southern Hemisphere’s vast oceans. However, her poem is much closer to the truth than our National Anthem’s lyrics, which magnanimously offers to share our ‘boundless plains’ (vast deserts) with all the world. We could probably do with lyrics less ludicrous.

Unsurprisingly the conclusion is that further growth is not sustainable. In their words, “With water, as with other limited resources, we can choose to grow toward calamity or shrink toward abundance.” How true.