Addressing the Water Shortage in Perth, Australia

TO: Mr. Tony Abbott, Prime Minister of Australia

FROM: Ed Isola, a Concerned Undergraduate Student at Davidson College

SUBJECT: Water Shortage in Perth

DATE: April 3, 2015


The city of Perth faces drastic water shortages in the upcoming future and will not be able to provide for its citizens unless an alternative water source is found or created. Therefore, Perth should begin exploring the implementation of a system designed to purify sewage water and transform it into clean, usable water.



A predicted 40% decline in rainfall in southern Australia could mean that the West Australian capital, Perth, will have to rely on alternative sources of water in the future.[i] A recent study by the National Oceanic and Atmospheric Administration examined the causes of rainfall decline in southern Australia over the past few decades, ultimately stating, “simulations of future climate with [our] model suggest amplified winter drying over most parts of southern Australia in the coming decades in response to a high-end scenario of changes in radiative forcing.”[ii] Furthermore, the study determined that drying is most noticeable over southwest Australia, “with total reductions in austral autumn and winter precipitation of approximately 40% by the late 21st century.”[iii]

Perth is particularly vulnerable to these rainfall changes because most of its rainfall occurs between May and September, and thus it could receive significantly lower rainfall on a yearly basis.[iv] This decrease in rainfall is crucial because, according to David Karoly, a climate scientist at Melbourne University, Perth will not be able to continue on as a city if an alternative water source is not found or created because there will not be enough water to supply the current population.[v]



            In order to create a more sustainable water source for Perth in the upcoming future, in addition to maintaining the current policy, three potential strategies have been crafted.

  1. Build New Reservoirs One approach to tackle shortages is to increase the stock of water available. The government would need to spend money to build new water reservoirs to hold more water for their population.
  2. Start Drinking Salt Water Desalination, or the process of converting salt water to drinking water, might transform the large amount of water surrounding Australia into a useful resource.
  3. Start Drinking Sewage Water Wastewater is safe to drink after passing through a treatment plant, so transforming runoff water from dishes, baths, and toilets could be a feasible solution.



            In the decision analysis for each of the four options, five important criteria were considered: (1) political feasibility, (2) administrative feasibility, (3) social costs and benefits, (4) environmental costs and benefits, and (5) economic costs and benefits. In order to easily categorize the costs and benefits of each option, I created a table to visually display the analysis. This table is attached at the end of the memorandum. I weighted each of these criterion in terms of its importance in the decision making process. Therefore, I assigned weights of 25% to the social, economic, and environmental costs, and 12.5% to political and administrative feasibility in order to reflect the thought process that policy change should positively affect as many stakeholders as possible. Additionally, each criterion is rated on a scale of one to three. A ‘1’ means an option has low feasibility, and the costs are greater than the benefits. A ‘2’ means there is a moderate feasibility, and the costs equal the benefits. A ‘3’ means there is a high feasibility, and the benefits are greater than the costs. Finally, a weighted score for each option is included in the table. This score is used to determine which option would be most effective.



This analysis offers an in-depth analysis of each of the four solutions using our outlined criteria.

  1. No Change, Continue with the Current Guidelines and Structures
  • The social impact and costs will be very high. The general population of Perth will not have an adequate water supply in the upcoming century and as a result will not be an inhabitable city.
  • Additionally, the economic costs will be high, as prices for water will undoubtedly skyrocket as the amount of water available declines.
  1. Build New Reservoirs
  • There would likely be political and economic resistance to this option. A similar idea was circulated in England in regards to a comparable water crisis, and estimates for constructing a new water reservoir were upwards of one billion dollars for each facility.[vi]
  • Environmentally, the construction of reservoirs might address the problem of water shortage, but it could negatively impact the environment in other ways. Critics argue reservoirs damage the environment and can create a substantial carbon footprint. [vii]
  1. Start Drinking Salt Water
  • The economic costs are relatively high for implementing such a system. In order to desalinate water, a large-scale desalination plant is necessary. The estimated costs for high functioning, efficient desalination plants is approximately 400 million dollars per plant. Each plant can supply roughly one million people. [viii]
  • Desalination could also have an adverse effect on the environment. Once the water has been purified, there is the challenge of what to do with the leftover salt, which could prove to be problematic. Additionally, “The WWF also warns large-scale seawater desalination could endanger marine life and is calling for further research into the tolerance of marine organisms and ecosystems to higher-salinity and brine waste.” [ix]
  1. Start Drinking Sewage Water
  • According to scientists, runoff water is perfectly acceptable to drink. Therefore, the political feasibility and technological feasibility are highly feasible.[x]
  • Drinking run off water would additionally have no adverse affects on the environment.
  • The economic costs would be relatively low, in comparison to other options. Water treatment is happening already, so the only new cost would come from diverting purified water from rivers into current water storage areas. [xi]
  • The largest concern with this option is the philosophical opposition many individuals have to drinking sewage water. Adrian McDonald, professor of environmental management at the University of Leeds, states, “there’s a philosophical concern, which I would share, that people really don’t like washing or drinking water that has come from someone else’s toilet, no matter how much science has said it’s perfectly pure.”[xii]



Based on the scoring system, the adaptation of a system designed to purify sewage water and transform it into a clean source of water is the best option. The political feasibility is high, and the technology exists to make such a system a reality. Furthermore, the implementation of a purifying system would provide clean water to the inhabitants of Perth while keeping social and environmental costs extremely low. Exploration and implementation of such a system within the next year would help protect both citizens and the environment and secure the future of their water supply.

Policy Options
Criteria Do Nothing/ Status Quo Build New Reservoirs Begin Drinking Saltwater Begin Drinking Sewage Water Criteria Weight
Political Feasibility 2 3 3 3 0.125
Administrative Feasibility 3 3 3 3 0.125
Social Cost and Benefits 1 1 3 3 0.250
Environmental Costs and Benefits 1 2 1 3 0.250
Economic Costs and Benefits 1 1 1 2 0.250
Option Score 1.6 2 2.2 2.8 1.000
Option Score (Weighted) 1.375 1.75 2 2.75



[i] Milman, O. South Australia Faces Water Crisis by End of Century Due to Climate Change. (2014). At <>

[ii] Delworth, Thomas L., and Fanrong Zeng. “Simulated Impact of Altered Southern Hemisphere Winds on the Atlantic Meridional Overturning Circulation.” Geophysical Research Letters 35.20 (2008): n. pag. Web.

[iii] Ibid

[iv] Milman, 2014

[v] Ibid

[vi] Bradford, V., Everitt, L. Eight Radical Solutions for the Water Shortage. BBC (2012). at <>

[vii] Ibid

[viii] Ibid

[ix] Ibid

[x] Ibid

[xi] Ibid

[xii] Ibid










  1. Bradford, V., Everitt, L. Eight Radical Solutions for the Water Shortage. BBC (2012). at <>
  2. Delworth, Thomas L., and Fanrong Zeng. “Simulated Impact of Altered Southern Hemisphere Winds on the Atlantic Meridional Overturning Circulation.” Geophysical Research Letters20 (2008): n. pag. Web.
  3. Milman, O. South Australia Faces Water Crisis by End of Century Due to Climate Change. (2014). At <>
  4. White, S. Our top ten environmental problems. ABC Environment (Australian Broadcasting Corporation). (2009) at <>


About Ed Isola

I am a Mathematics and Computer Science and Political Science double major at Davidson College in Davidson, North Carolina. Outside of writing, I enjoy wrestling and playing music.

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