National Water Account 2018

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Key findings

Climate and water

Water Accounting Statements

Supporting information

Region description

Reference information

Ord: Statement details

Water assets

• Water asset volumes in the region at 30 June 2018 were 8,989,812 ML, more than 99% of which is water held in storages. The remaining amount is water held in rivers.

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

• Storage volumes decreased from 108% full at 30 June 2017 to 82% full (8,985,344 ML) at 30 June 2018.
• Water in Lake Argyle makes up more than 98% of the region’s total surface water storage.

Figure S2 Percentage-full volume on 30 June 2018 for each storage and total daily storage volume from 2015–2018 (inset)

• All storages were more than 80% of capacity at 30 June 2018, similar to previous years.
• The normal filling and spilling of the storages did not occur due to below-average rainfall in the upper catchment areas during most of the wet season.
• Storage volumes peaked in early-March 2018 following above-average rainfall in January 2018.
• 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 Ord region refer to the volume of allocation remaining on licence entitlements at the end of the 2017–18 year. 

• Most of the water supply licences for the region do not have a water management year that ends on 30 June. Therefore, the allocation remaining is the unused component of the annual allocation for these entitlements.
• A more detailed description of water allocations and associated water rights in the Ord region is given in the Water access and use note.

Water asset increases

• Total water asset increases for the year was 4,255,402 ML.
• The key item contributing to water asset increases for the region was runoff, which made up 85% of the total water asset increases.
• Runoff was much lower than the previous year when near record wet season rainfall conditions were experienced across the entire region (see the 2017 Account).
• Groundwater increases represents recharge from the landscape, which generally changes little from year to year.

Water asset decreases

• Total water asset decreases for the year was 5,904,962 ML.
• The key item contributing to water asset decreases for the region was outflow, which made up 61% of the total water asset decreases.
• Outflow was more than 50% below average, and much lower than the previous year, due to the relatively poor rainfall across the region for most of the year.

Water flows

• Total water inflows to the region was 4,255,402 ML, equal to the volume of Water asset increases.
• Total water outflows from the region was 6,151,403 ML, slightly higher than the volume of Water asset decreases (5,904,962 ML) as it includes 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 and groundwater stores 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 value is primarily attributed to the fact that river losses cannot be quantified in the account, as well as uncertainties associated with the runoff estimate (see Methods).