Desalination: The Aussie Way

It has been a while since we’ve discussed desalination. Desalination is a process that uses reverse osmosis to convert salt water into fresh drinking water. Our last desalination post featured San Diego and its long-term ambitions to expand desalination due to water shortages and the rising costs of importing water from northern California.

Australia has been desalinating water since 2006, when Perth opened the nation’s first desalination plant. In one of the country’s biggest infrastructure projects in history, Australia’s five largest cities are spending $13.2 billion on desalination plants. Such enthusiasm for aggressive expansion has been motivated by intense droughts across the country. The executive director of the Water Services Association of Australia described the billions of dollars as “the cost of adapting to climate change”. Droughts have been intensified by climate change and desalination will make a significant contribution to the country’s water supply and hopefully for contingency situations when droughts come again in the future.

There are critics of course. One of the main arguments against such an expansion is that Australia’s population is not growing as fast as the past government projected. Called “Big Australia”, the previous government’s projected that the population would rise to 36 million in 2050, from 22 million now.

The focus of attention appears to be on Queensland, the nation’s fastest growing region. Queensland suffered an intense drought from 2000 to 2009. A desalination plant in this area supplies 6 percent of the region’s water needs and has the capacity to deliver 20 percent. The drought did lead to other incentives such as subsidizing the purchase of home water tanks to capture rainwater. A number of dams were built, along with wastewater recycling facilities and pipes. Thus, Queensland has reacted to water shortages mainly through what we call “hard-path approaches” which I have argued in previous posts (and in my honours thesis) is not a holistic approach to water management.

With Queensland’s jubilation for desalination construction, other cities like Sydney, Melbourne and Adelaide have followed suit. I must stress that the power needed to remove salt from seawater accounts for up to 50% of the cost of desalination, and Australia relies on coal, a major emitter of greenhouse gases, to generate most of its electricity. To make smart progress on desalination and to avoid stiff opposition from tough critics, I think Australia must do two things:

1) Develop a system whereby excess water produced from major desalination plants is sold to municipalities without such desalination plants (there are many drought prone regions that could benefit from having a contingency water supply that desalination could provide). The costs must be transparent and distributed equally and at a low cost to those cities. Indeed, desalination projects need to slow down and the government must focus on fair distribution with an adequate amount of “contingency water” stored in reservoirs for imminent droughts.

2) Seeing as desalination will be the solution for Australia’s future water supply, and the fact that desalination is powered mostly through coal, the Australian government must focus on expanding renewable energy projects such as solar energy. Given that Brisbane (the capital of Queensland) receives over 3000 hours of sunshine every year, the region’s desalination plant would benefit from renewable sources like solar to ease pressure on coal and reduce aggregate CO2 emissions.

Key message: Australia will become (if it isn’t already) the world’s biggest user of desalination. With climate change uncertainty and the frequency of droughts, it must focus on conserving water for contingency situations. It does not have to expand desalination plants but instead focus more on practical and sustainable goals like powering them through renewable energy and expanding water conservation education in elementary and secondary schools.