Adelaide

The unaccounted-for difference is the difference between the directly measured closing water asset and the closing water asset calculated from the statement of physical flows. The total unaccounted-for difference in the Adelaide water accounting statement is 220,348 ML or about 150% of the total water assets. In general this large difference is due to:

• uncertainty in the line items arising from the quantification approaches
• extent to which assets and flows in the water accounting statements represent the physical system.

The unaccounted-for difference for the individual stores in the Adelaide region is presented in the table below.

The unaccounted-for difference for the groundwater store is calculated according to the table below.

The groundwater store has the greatest unaccounted-for difference (269,352 ML) due to:

• only partial quantification of the groundwater asset. Only the allocated groundwater asset in prescribed areas with a water management plan has been quantified. The extractable portion of groundwater in areas covered by a Notice of Prohibition and in areas not declared as prescribed has not been quantified. In contrast, groundwater flows (e.g. recharge and extraction) have been quantified for the entire region.
• exclusion of some significant flows (e.g. recharge from surface water, groundwater evapotranspiration and discharge)
• large uncertainty associated with some groundwater terms (e.g. diffuse recharge and regional flow).