National Water Account 2018

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Key findings

Climate and water

Water Accounting Statements

Supporting information

Region description

Reference information

Canberra: Statement details

Water assets

Storages

• Water asset volumes in the region at 30 June 2018 were 236,639 ML, more than 80% of which is water held in storages.

Figure S1 Total storage volume in the region at 30 June 2018 compared with the previous 8 years

• Storage volumes decreased from 84% full at 30 June 2017 to 70% full (196,705 ML) at 30 June 2018. This is the region's first decrease in end of year storage volume in five years.
• Below-average rainfall throughout most of the year, including a very dry autumn period, contributed to the relatively large decrease in storage volume.
• In 2013 the Cotter Reservoir was enlarged, increasing the region's total storage capacity to better deal with water demand during periods of drought (see 2013 Account).

Figure S2 Percentage-full volume on 30 June 2018 for each storage

• Except for a small rise in storage in December 2017 following high rainfall in November–December, storage volumes declined for most of the year.
• The decrease in Googong Reservoir storage volume (73% at 30 June 2018) is significant. The reservoir has remained full, or near full, since the end of the Millennium Drought in 2010, until the start of 2017, where it has steadily decreased by almost 30%.
• More detailed information on the individual storages within the region is available on the Bureau of Meteorology's Water Storage website.

Water liabilities

• Water liabilities in the Canberra region refer to the volume of allocation remaining on licence entitlements at the end of the 2017–18 year.

• The water supply licences for the region have a water management year that ends on 30 June. The portion of water allocation that has not been abstracted at the end of the water year is either forfeited or is carried over into the next water year.
• For individual users and the urban licence entitlement the unused portion of the allocation is assumed to be forfeited and the allocation remaining at the end of the year was 0 ML.
• A more detailed description of water allocations and associated water rights in the Canberra region is given in the Water rights note.

Water asset increases

• Total water asset increases for the year was 749,052 ML.
• The key items contributing to water asset increases were runoff  and inflow, which together made up more than 56% of the total water asset increases. Runoff and inflow were both below average, reflecting the dry conditions throughout the year (see Climate and water).
• Urban water system increases largely comprised of increases in the urban claim on surface water, which is equal to 100% of the entitlement volume; and wastewater collected, which changes little from year to year.

Water asset decreases

• Total water asset decreases for the year was 557,859 ML.
• The key item contributing to the water asset decrease for the region was outflow, which made up almost 50% of the total water asset decreases. Outflow was below average, which can be attributed to the drier conditions experienced throughout the region (see Climate and water).
• Urban water system decreases primarily represent discharge: surface water and supply system delivery: urban users, which generally change little from year to year.

Water flows

• Water inflows to the region totaled 730,250 ML, lower than the volume of Water asset increases (749,052 ML) as it excludes the volumes corresponding to accrual transactions—forfeitures of the urban system entitlement to surface water (see the Water liabilities section above).
• Water outflows from the region totaled 592,085 ML, higher than the volume of Water asset decreases, as it includes the flows corresponding to the accrual transactions—allocated diversions and allocated extractions (see the Water liabilities section above).
• A detailed description on all the water flows associated with the surface water store, groundwater store, and urban water system is provided in the  Water stores note.

Unaccounted-for difference

• The unaccounted-for difference is the volume necessary to reconcile the opening water storage and closing water storage with the total water inflows and total water outflows reported in the water accounting statements.

• The relatively high unaccounted–for difference volume is primarily attributed to uncertainties associated with the runoff estimate and groundwater recharge from surface water  (see Methods).