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National Water Account 2017

Ord: Water stores

Well above-average rainfall during the year, particularly January–February, the typically wetter months of the year, contributed to high runoff across the region and an increase in storage volumes. As a result of these climate conditions, there was a decrease in water use during the year.

 

 

 

For a water balance on each of the region's water stores for the 2016–17 year scroll down this page or click on the links below:

 

 

Surface water store

Lake Argyle, Ord region. Source: istock © czardases

 

Table S4 Water balance for the surface water store
 2017
ML
2016
ML
Opening surface water store8,072,7649,942,970
Inflows28,297,2924,306,338
Outflows(20,111,818)(5,219,211)
Balancing item(4,425,862)(957,333)
Closing surface water store11,832,3768,072,764

 

  • The volume of surface water in the region increased from 8,072,764 ML at 1 July 2016 to 11,832,376 ML at 30 June 2017.
  • The balancing item of –4,425,862 ML is approximately 37% of the closing surface water store. Such a high balancing item is attributed to the fact that river losses cannot be quantified in the account, as well as uncertainties associated with the runoff estimate (see Methods).

 

Surface water flows

 

Figure S3 Water inflows and outflows for the surface water store during the 2016–17 year

 

  • The largest natural water flows were runoff and outflow. Both were much higher than the previous year, reflecting the well above-average rainfall conditions experienced across the region (see Climate and water).
  • Evaporation was less than that which occurred during the previous year, which can be attributed to the increased rainfall (and hence cloud cover) that occurred during the year.

 

Figure S4 Map of allocated surface water diversions during the 2016–17 year in the region's key water management areas
Figure S4 Allocated surface water diversions during the 2016–17 year in the region's key water management areas

 

  • Total surface water diverted in the region was 197,546 ML, a decrease from the previous year.
  • More than 83% of the total diversion was for irrigation scheme supply; 16% was supplied to individual users and less than 1% was used for the urban system.
  • For a more detailed description of the water usage in the region, and the associated entitlements, see the Surface water rights note.

 

Groundwater store

Windmill in the outback, Ord region. Source: istock © Totajla

 

Table S5 Water balance for the groundwater store
 2017
ML
2016
ML
Opening groundwater store
Inflows7,5798,572
Outflows(7,579)(8,572)
Balancing item00
Closing groundwater store

 

  • The volume of groundwater in the region is assumed to remain unchanged throughout the year.
  • Total groundwater inflow is assumed to equal the volume of groundwater extracted, so the groundwater store is assumed to balance (i.e. the balancing item is zero).

 

Groundwater flows

 

Figure S5 Water inflows and outflows for the groundwater store during the 2016–17 year

 

  • Groundwater movement across the region boundary as well as surface water–groundwater interactions are considered to occur within the region; however, these flows could not be quantified due to a lack of available data.
  • Total groundwater extracted in the region was 7,579 ML, a 12% decrease from the previous year.

 

Figure S6 Map of allocated water extractions during the 2016–17 year in the region's key water management areas
Figure S6 Allocated groundwater extractions during the 2016–17 year in the region's key water management areas

 

  • 77% of the total extraction was for individual users and 23% was used for the urban system.
  • For a more detailed description of the water usage in the region, and the associated entitlements, see the Groundwater rights note.