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National Water Account 2019

Ord: Statement details

  • Below-average rainfall for most of the year contributed to low storage inflows and runoff across the region.
  • End of year storage volume dropped to 54% full, the second successive annual drop in storage.

For further information on the region's water accounting statements scroll down this page or click on the links below:

 

Water assets

Kununurra Diversion Dam, Ord region (Water Corporation © Darryl Perroni)

 

  • Water asset volumes in the region at 30 June 2019 were 5,840 GL, more than 99% of which is water held in storages. The remaining amount is water held in rivers.

 

Graph of total storage volume in the region at 30 June 2019 compared with the previous 9 years
Figure S1 Total storage volume in the region at 30 June 2019 compared with the previous 9 years

 

  • Storage volumes decreased from 82% full at 30 June 2018 to 54% full at 30 June 2019, the lowest end-of-year storage volume in more than 10 years.
  • Water in Lake Argyle makes up more than 98% of the region’s total surface water storage.

 

Map showing percentage-full volume on 30 June 2019 for each storage and total daily storage volume from 2013–2019 (inset)
Figure S2 Percentage-full volume on 30 June 2019 for each storage and total daily storage volume from 2013–2019 (inset)

 

  • For the second succcesive year, the normal filling and spilling of the storages did not occur due to below-average rainfall in the upper catchment areas during the wet season.
  • Except for small increases in storage during January–February 2019 following wet season rainfall events, storage volumes declined for most of the year.
  • More detailed information on the individual storages within the region is available on the Bureau of Meteorology's Water Storage website.

 

Water liabilities

Lake Argyle, Ord region (istock © anonymous)

 

  • Water liabilities in the Ord region refer to the volume of allocation remaining on licence entitlements at the end of the 2018–19 year.

 

Table S1 Volume of surface water allocation remaining at 30 June 2019
DescriptionIndividual users (ML)Urban system (ML)Irrigation scheme (ML)
 Opening balance at 1 July 201810,268670300,702
add Allocation35,100700371,800
less Allocated diversion35,240425271,224
less Adjustment and forfeiture0275168,204
 Closing balance at 30 June 201910,128670233,074

 

Table S2 Volume of groundwater allocation remaining at 30 June 2019
DescriptionIndividual users (ML)Urban system (ML)
 Opening balance at 1 July 20181,1552,252
add Allocation5,5482,700
less Allocated diversion4,4241,778
less Adjustment and forfeiture1,124922
 Closing balance at 30 June 20191,1552,252

 

  • 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 flows

Champagne Springs, Ord region (istock © samvaltenbergs)

 

  • Total surface water flows into the region's storages was 2,483 GL. The key item contributing to surface water inflows was runoff, which made up 80% of the total surface water inflows for the region.
  • Runoff was much lower than average (based on modelled data from 1971–2019) due to the relatively poor rainfall across the region. This was the second successive year of below-average runoff across the region.
  • The key item contributing to surface water outflows from the region's storages was river outflow, which made up 55% of the total surface water outflows. River outflow was below average due to the dry conditions and low runoff across the region.
  • A detailed description on all the water flows associated with the surface water and groundwater stores, including consumptive water use, is provided in the Water stores note.

 

Unaccounted-for difference

Irrigation area, Ord region (istock © Mark Higgins)

 

  • 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.

 

Table S3 Calculation of unaccounted-for difference for the 2018–19 year
DescriptionVolume (ML)
 Closing water storage at 30 June 20195,840,288
less Total inflows2,489,371
add Total outflows5,175,444
less Opening water storage at 1 July 20188,989,812
 Unaccounted-for difference(463,451)

 

  • The 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).