This discussion paper argues that assumptions of future water abundance are dangerously flawed. It presents original data analysis of Australia's water use over the past four decades, and summarises recent studies of the impacts of climate change on water availability. The paper reviews recent urban water demand and population projections published by Australia's mainland urban water utilities, and examines the costs and risks of increased reliance on desalination. It explains why expanded desalination, rather than being a solution, is a further symptom of the financial, environmental and social costs of population growth.

For 200 years, Australia’s expanding population has driven demand for more water. As population continues to grow, concerns about water security are also mounting. Recent major droughts (1997-2009 and 2017-19) have put pressure on water supplies in both small towns and capital cities, prompting state governments to commission large-scale desalination plants. 

Population growth slowed (but did not halt) during the Covid-19 pandemic, when migrants leaving Australia briefly exceeded those arriving. Then the government restarted immigration at unprecedented levels: six times the long-term average. Even if the government succeeds in reducing immigration to pre-Covid levels, Australia will grow from 27 million to 40 million people inside of 40 years, and continue growing indefinitely thereafter. There has been little discussion about whether there will be enough water to support this goal, particularly in light of the increasing impacts of climate change. 

Despite Australia being the driest continent with the least run-off and most variable rainfall, water planning simply assumes the population projections of the Treasury Department must be achieved. It is further assumed technological fixes, particularly desalination, will save the day.