Desalination, Will it Work this Time?

By Graham Pinn

In 2022, SEQ water advised that the population growth had brought forward likely water shortages for South East Queensland to as early as 2024. The Labor Government is considering decisions to expand the rarely used Gold Coast desalination facility, and build a new plant on the Sunshine Coast, with completion by 2035. As was the case, with droughts in the early 2000’s, the knee-jerk response, has been undermined by major floods. Relying on faulty Bureau of Meteorology El Nino forecasts, predictions which may now turn into La Nina!!

Australia has throughout its history been a land of drought, floods, and fire, it is recognised as the driest inhabited continent in the world. With another El Nino event supposedly looming, the country’s rapidly expanding population, (the latest estimates have increased from 33 to 36 million by 2050) is putting pressure on water availability. Rather than building new dams, it seems the option of desalination plants is now back on the agenda, as Queensland re-invents a previous, failed policy.

Courtesy of La Nina in 2021-2, we had heavy rainfall, around 15% above average, with multiple floods ensuing; much of this water, in some places an annual fall in weeks, drained out to sea. As in previous events, water progressed to lake Ayre, with filling comparable to the La Nina event of 1974; the lake has only filled 4 times in 100 years; currently major flows of water are heading there again.

Fortunately, much of this rain at least filters through the ground into the Great Artesian Basin and, no thanks to politicians, is conserved; this 1.7 million square kilometre reserve, in Eastern Australia, is up to 3000 metres deep and bore water has supplied a less populated country for many years. These ongoing natural events are made more important, not by any changing climate, but by the demands of growing immigration; the current focus has been on housing shortages, but water (and electricity) supply, are even more critical.

Apart from population demands, there are three, other, sometimes forgotten, reasons for building dams. Flood mitigation is the first, with these events recently much in evidence on the East Coast of Australia. Second, is hydro power generation; this was once considered acceptable, as in the dysfunctional Snowy Hydro 2 scheme, with its soaring cost and delays, but has otherwise been discounted apart from the wetter climate of Tasmania. The third use is for irrigation; the Paradise dam in Bundaberg, built by public/private enterprise (another story in itself), proved a great success, until its poor construction was revealed.

Past dam cancellations have been driven by environmental activism rather than reality. The Tasmanian, Franklin dam, intended for hydro-electric power, was cancelled in 1983, following prolonged activism. The Wolffdene dam, cancelled in 1989, would have flooded the Albert Valley and provided extra water for the current needs of South-East Queensland. The Hell’s Gate for irrigation and water supply outside Townsville, has been under consideration since 1938!

The Traveston dam, again in SE Queensland, had been a project to dam the upper reaches of the Mary River and connect to other dams to supply Brisbane. The land had been bought, and roads built around the area; environmental arguments resulted in a delay of 4 years, and ultimate cancellation by the Federal Labor Government in 2009. The projected cost of the build had been $1.7 billion, eventually nothing was achieved – at a cost of $460 million.

The plan to build a new large dam at Urannah, flooding the Broken River Valley in Central Queensland was to irrigate 20,000 hectares of land, provide water for mining and urban use and generate electricity; it took 40 years to get that far, and has now been cancelled by the Federal Government, because of” threat to the Great Barrier Reef, and inadequate consultation with traditional owners”.

Plans to raise dam heights around Sydney have been similarly thwarted by environmentalists, leading to uncontrolled flooding and future water shortages as the population expands. The Warragamba dam is, once more, at capacity; it has overflowed in 2012, 2016, 2021 and 2022, perhaps 2024 also; someone needs to take note!

The authoritative comments of noted wombat expert, Tim Flannery, that dams would never fill again, were taken to heart by environmentalists, during the prolonged drought period from 2006 to 2012; desalination plants were completed in all coastal capital cities, except in those with secure rainfall or inland location – Tasmania, ACT and Northern Territory. Perth and Adelaide had always had less water security, with no access to the Artesian Basin bore water. The total cost of constructing the 6 plants (WA had 2) was over $9 billion, with significant ongoing maintenance costs.

The alternative option to dams, is to convert sea water by reverse osmosis into fresh, but it is energy intensive, and requires large amounts of electricity; with Australia’s environmental concerns, additional renewable energy supply is also needed, adding to the cost. Currently, the world’s largest desalination plants, in the Middle East, are powered by oil and gas because, unlike Australia, power is still cheap there, and there is no concern about climate change.

In the rush to provide water security with the previous drought, the first desalination plant was completed in 2006 in WA, at a cost of $400 million, capable of supplying 17% of Perth’s population. It was followed up by a second, completed in 2012, at a cost of $1.4 billion, adding another 29% capacity. A wind farm was completed in 2013 at a further cost of $200 million, capable of supplying 180GWh of electricity to offset energy demands of the plants. Perth has little groundwater and these plants have been in continuous operation, in 2013 providing an average 29% of the city’s needs, with running costs of $70 million annually; a 2022 review has recommended doubling the capacity, at an additional cost of $320 million.

Adelaide, like Perth has limited access to ground water and, with the uncertain flows from the Murray River, is more vulnerable to drought. Its desalination plant was completed in 2012 at a cost of $1.8 billion and is big enough to supply 60% of the city’s need. The plant operated from 2012 to 2016 supplying around 20%, and again from 2019 as flows down the river were reduced for conservation purposes; current output has again increased, reducing demand on the river. Its maintenance cost is $130 million annually.

Brisbane dam water storage had fallen to 20% by 2007; the plant, built on the Gold Coast at a cost of $1.2 billion, was predicted to supply 18% of the city’s needs. By the time of its completion in 2009, dam levels had risen to 80%, increasing to 100% by 2010. On completion the plant was mothballed and has been little used; running costs, when not in use, are estimated at $15 million annually. It was restarted in 2020 to pump water to the main Wivenhoe dam, which had missed rainfall, and was at 40%, subsequently that dam was full to overflowing, with all other Brisbane dams at 100% capacity. In 2024, many Queensland dams are back to 100% capacity, averaging 75%.

Sydney’s dams were, as now, 100% full in 1998, by 2007 levels had fallen to 34%. NSW completed its desalination plant in 2010, at a cost of $1.9 billion, capable of supplying 17% of the city’s requirements, electricity was offset by wind farm construction. The plant was used briefly from 2010 to 2012, by which stage dams were at 80% capacity; when not in use, maintenance costs are $600,000 a day, an estimated cost per household of $90 per year.

Melbourne water storage fell as low as 25% in the drought but, by the time of plant completion in 2012, at a cost of $3.5 billion, levels had recovered to 80%. It can supply 37% of the city’s need and was briefly used in 2017, and again in the next 2 years. The cost to the residents is reputedly a staggering $600 million a year, 16% of the State’s GDP. Most cities have been saddled with billions of dollars in construction and ongoing maintenance costs, to little purpose. As the population is now expected to reach 36 million by 2050, new dams are required for water security and flood control.

A survey in 1988 suggested the cost of desalinated water was between five, and ten times, standard costs. Subsequent surveys elsewhere have suggested desalinated water is about twice the price of recycled water and five times that from dams, with variation depending on the cost and availability of electricity supply.

Had we but built dams, we could have reduced flooding, increased hydro electricity generation, and provided water security for agriculture and future population demands. Instead, we are looking at an alternative environmental destruction to build renewable energy to power desal plants. Politicians, who succumbed to the activists’ and environmentalists’ ideology, should bow their heads in shame. As the population expansion is actively promoted, the failed desalination option is back on the agenda; politicians refuse to consider the only other, currently politically unacceptable but much cheaper alternative, of water recycling.

With the South-East Queensland population predicted to expand from under 4 to 6 million by 2046, water is the most fundamental of planning priorities; additional supplies were thought to be needed as early as 2030, this was brought forward with the projected El Nino event. The Gold Coast desal plant has been on care and maintenance since 2013, and it would take 2 years to recommission the never used, and politically challenging, Western Corridor Recycling scheme (original cost $2.5 billion). The latest plan, a new desal plant on the Sunshine Coast, is projected to cost of between $4 and $8 billion, no definitive decisions will be made ‘til after the next election, in 2025; the project would add 15% to water bills, already the most expensive of any state.

More water is just one of the many expensive infrastructure-demands excessive immigration will require; Government needs to reconsider the consequences and alternatives to this latest plan, following the unexpected rains of 2023-4, obfuscation will rule. Currently the only practical choices for future adequate water supply are recycling, or the long-neglected dam building; had we made progress with nuclear powered electricity generation, it could have provided the extra electricity the population will need, as well as power for desalination.

The population explosion has increased the risk of water shortages; desalination is expensive and requires vast amounts of increasingly unavailable electricity, the only solution is to confront environmentalists and build more dams. As desal plants are back (hopefully only briefly) on the agenda, the writing should be on the dam wall, does the government have the intestinal fortitude to confront activists, and read it?

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Graham Pinn was a medical doctor for 50 years and has worked in 10 different countries throughout the world. “In retirement there is time to fight the good fight against global warming misinformation, before the lights go out.”