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 is220,348 ML or about 150% of the total water assets. In general, this large difference is due to:
The unaccounted-for difference for the individual stores in the Adelaide Region is presented in the table below.
|
Store |
Measured/estimated (ML) |
Calculated from physical flows (ML) |
Difference (ML) |
Difference (%) |
|---|---|---|---|---|
|
Connected surface water |
110,546 |
72,369 |
(38,365) |
(35) |
|
Groundwater |
39,268 |
308,620 |
269,352 |
686 |
|
Water distribution system |
1,676 |
(9,709) |
(10,639) |
(635) |
|
Total water assets |
151,490 |
372,412 |
220,348 |
146 |
The unaccounted-for difference for the water distribution store is calculated according to the table below.
|
Calculation |
Line item |
Volume (ML) |
|---|---|---|
|
Opening balance (as at 1 July 2009) Water distribution system store |
1,670 |
|
|
add |
TOTAL 19 Water distribution system inflows |
153,313 |
|
minus |
TOTAL 20 Water distribution system outflows |
163,946 |
|
minus |
Closing balance (as at 30 June 2010) Water distribution system store |
1,676 |
|
Unaccounted-for difference |
(10,639) |
The absolute unaccounted-for difference is relatively small for the water distribution store (10,639 ML). The percentage difference (635%), however, is very large because only the small volume held in pipes and tanks has been recognised as the asset for the water distribution system. The percentage difference is only 7% when calculated as a percentage of the inflows to the water distribution system (rather than as a percentage of the asset).
National Water Account 2010
Related links
Water links
