Climate change and Sydney's water balance

The Sydney Water Balance Project is the only research to date that has tried to determine the potential impacts of climate change on greater Sydney’s water supply and demand.

The results of the Sydney Water Balance Project provide information on how greater Sydney’s water supply may be affected by climate change over time. However, climate change is an evolving science. There will always be uncertainty associated with climate change projections, due to uncertainties about future levels of greenhouse gas emissions, the lack of consistent climate data and limitations of global climate models to estimate climate impacts at the regional level and to model future droughts and the evolving nature of climate science.

In relation to water supply, the results indicate there may be decreases in annual rainfall and runoff in the inland catchments and minor increases in coastal catchments by 2030.

Over the short term, these findings do not fundamentally change our approach to managing greater Sydney’s water supply; however they do highlight the importance of:

managing risk by having an appropriate buffer between supply and demand
having an understanding of the likely pressure points on the supply and demand balance in the future
having the ability to respond to changing conditions due to both climate change and climate variability
continuing to improve our knowledge of climate change impacts on greater Sydney’s water supply and incorporating this knowledge into future iterations of the Metropolitan Water Plan.

Findings from the Sydney Water Balance Project also indicate that climate change:

will likely result in an increase in temperature by 2030
may result in an increase in evaporation throughout the catchments, with the most significant increase being recorded in the Goulburn area (which reflect evaporation changes in the inland areas of Sydney catchment
may result in a very minor increase in water demand in greater Sydney by 2030.

To read more about the Sydney Water Balance Project you can download the full summary report and technical reports or check out our frequently asked questions, which have been prepared to help answer all your questions to do with climate change and Sydney’s water supply.

Downloads

Climate change and its impacts on supply and demand - summary report, October 2010
Technical report - Climate change and its impacts on Sydney's water supply, Sydney Catchment Authority 2009
Technical report - Collaborative Climate Change Study - Demand side impacts, Final report, Sydney Water 2009
Technical report - High resolution climate change projections and impacts, UNSW 2009.