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National Water Account 2016

Sydney: Outlook

Average rainfall conditions are expected across the Sydney region during the 2016–17 year. This is likely to result in only a marginal drop in storage from the 98% full at 30 June 2016. Water use during the year is expected to be similar to the 2015–16 year.

 

SYD_KeyMessage

 

 

Future prospects

This section looks forward over the next reporting period and considers what water inflows, commitments and other releases (e.g. dam operation releases and spills) might affect the region's water resources during the 2016–17 year. Figure S12 shows that there is a surplus of available water assets and future water rights over water liabilities and future water commitments that are expected to be settled within 12 months of the reporting date.

 

Figure S12 Water outlook for the Sydney region for 2016–17

Figure S12 Water outlook for the Sydney region for 2016–17

 

Expected inflows

At the time of publication, rainfall over the Sydney region during the first nine months of the 2016–17 year (July–March) was generally average to above average (Figure S13) and higher than the same period last year. This has led to increases in surface water storage volumes across the region. According to the Bureau of Meteorology's Water Storage website, storage volumes at 30 March 2017 were 96% full compared with 89% full at the same time last year.


Figure S13 Rainfall deciles for the Sydney region from July 2016–March 2017
Figure S13 Rainfall deciles for the Sydney region from July 2016–March 2017
 

 

The Bureau's climate outlook (released on 30 March 2017) indicates a high probability of below-average rainfall over most of southern Australia, including the Sydney region, for the next three months (April–June 2017). This outlook is influenced by warming of tropical Pacific sea surface temperatures and a cooler than average eastern Indian Ocean. Therefore, given the current above-average soil moisture conditions across the region in March 2017 (see the Bureau's Australian Landscape Water Balance product), annual streamflows and storage inflows are expected to be average during the 2016–17 year.

The expected inflows for the 2016–17 year are based on the 2014–15 year, a period when similar average rainfall and soil moisture conditions were experienced. Based on these assumptions, the combined expected precipitation (approximately 100,000 ML) and river inflows into the storages (approximately 1,825,000 ML) could exceed the expected evaporation from the storages (approximately 125,000 ML) during the year.

 

Future commitments

The expected diversions and extractions are based on water use data for the 2015–16 year; however, other water releases such as dam spills are expected to decrease over the next reporting period. 

 

Contingent water assets

The Sydney region's desalination plant at Kurnell has the capacity to produce 91,250 ML per year (Sydney Water Corporation 2013). As no desalinated water was transferred into the Sydney region during the 2015–16 year, the production capacity of desalinated water at Kurnell (91,250 ML) can be considered a contingent water asset.

More details on the Sydney region's desalinated water supply are provided in Desalinated water in 'Region description'.