Climate change introduces uncertainties which create difficulties in water supply planning for water authorities. This uncertainty stems from various sources including future concentrations of atmospheric carbon dioxide (driven by anthropogenic activities), how much warming will occur as levels of carbon dioxide increase, and how other climate variables (especially rainfall) will change as a result of this warming. Further uncertainties are introduced when alterations in climate variables are converted into changes in streamflows and system yields.
AECOM has conducted climate change risk assessments for several Victorian water authorities and also incorporated recently released data from the South Eastern Australian Climate Change Initiative (SEACI) into Water Supply Demand Strategies. We are currently undertaking a Cost Benefit Analysis of potential adaptation options for a Victorian Water authority to optimise the timing and scale of proposed adaptation solutions on behalf of the Department of Climate Change. Through this work, a number of opportunities for embedding climate change into planning processes at both the operational and strategic level have been identified.
Examples of how appropriate climate change projections can be embedded in organisational processes include:
• Using recently released rainfall and runoff projections available at the catchment level up to 2030 from the South East Australian Climate Change Initiative (SEACI)
• Ensuring that underlying climate change projections used in Water Supply Demand Strategies and Sustainable Water Strategies are consistent (they often are not)
• Changing strategic planning processes to favour reversible and flexible options or “no regret‟ strategies that yield benefits even in the absence of climate change
• Undertaking Cost Benefit Analyses of potential adaptation options to optimise the timing and scale of these.