Sydney: Water resources and systems

Introduction
The following set of notes provides consolidated reports for each of the water stores and systems within the Sydney region during the 2014–15 year. Information on all water flows to and from each water store and system are presented in this note, including between-store flows and transfers that are not presented in the consolidated water accounting statements (which are shown in italics).
For more information about the region, please refer to the General description section of the 'Contextual information'. For more information on between-store flows and transfers that occur in the region, please refer to the Supporting information note.
Surface water
Statement of Water Assets and Water Liabilities
The Statement of Water Assets and Water Liabilities presents the volume of water assets and water liabilities at the start and end of the reporting year.
Surface water assets of the region include physical water assets (e.g. storages and rivers) and rights or claims to water. Surface water liabilities include commitments to deliver water to users at the end of the year. The closing net water assets are the volume of surface water assets in the region minus the surface water liabilities at the end of the reporting year (Figure N14).
Figure N14 Surface water assets and surface water liabilities for the region at 30 June 2015
Details on the region's surface water assets and surface water liabilities for the 2014–15 year are also provided in Table N18.
2015 ML | 2014 ML | |
Water assets | ||
Storages | 2,661,678 | 2,386,167 |
Unregulated river | 3,288 | 1,903 |
Regulated river | – | – |
Lakes and wetlands | – | – |
Inter-region claim on water | 2,367 | 2,367 |
Total water assets | 2,667,333 | 2,390,437 |
Water liabilities | ||
Allocation remaining: individual users | 0 | 0 |
Allocation remaining: urban system | 0 | 0 |
Total water liabilities | 0 | 0 |
Opening net water assets | 2,390,437 | 2,840,751 |
Change in net water assets | 276,896 | (450,314) |
Closing net water assets | 2,667,333 | 2,390,437 |
Statement of Changes in Water Assets and Water Liabilities
The Statement of Changes in Water Assets and Water Liabilities presents the changes in water assets and water liabilities that occurred during the reporting year.
This statement is prepared on an accrual basis. Figure N15 shows the transactions that changed the surface water assets and surface water liabilities of the region, including:
- accrual (non-physical) transactions, indicated by the glass of water symbols
- actual water flows (both natural and engineered), indicated by the arrows.

Figure N15 Changes in surface water assets and surface water liabilities for the region during the 2014–15 year
2015 ML | 2014 ML | |
Water asset increases | ||
Precipitation | 155,848 | 91,668 |
Runoff | 5,239,511 | 1,986,928 |
Discharge: wastewater | 83,053 | 59,678 |
Discharge: user | 8 | 2,485 |
Claims: inter-region | 11,834 | 11,834 |
Total water asset increases | 5,490,254 | 2,152,593 |
Water liability decreases | ||
Adjustment and forfeiture: individual users | 134,553 | 116,485 |
Adjustment and forfeiture: urban system | 497,693 | 483,557 |
Total water liability decreases | 632,246 | 600,042 |
Water asset decreases | ||
Evaporation | 166,963 | 168,947 |
Outflow | 4,403,694 | 1,724,770 |
Diversion: statutory rights | 32,530 | 32,530 |
Claims: inter-region | 8,766 | 4,335 |
Total water asset decreases | 4,611,953 | 1,930,582 |
Water liability increases | ||
Allocation: individual users | 159,480 | 159,462 |
Allocation: urban system | 1,040,588 | 1,040,588 |
Total water liability increases | 1,200,068 | 1,200,050 |
Balancing item—surface water | (33,583) | (72,317) |
Change in net water assets | 276,896 | (450,314) |
Statement of Water Flows
The Statement of Water Flows presents the actual water inflows and outflows associated with the water stores of the region that occurred during the reporting year.
Figure N16 shows the actual surface water flows, including flows corresponding to the accrual transactions shown in Figure N15 above (red arrows).
Figure N16 Surface water flows for the region during the 2014–15 year
Detail on the surface water flows for the 2014–15 year is also provided in Table N20.
2015 ML | 2014 ML | |
Water inflows | ||
Precipitation | 155,848 | 91,668 |
Runoff | 5,239,511 | 1,986,928 |
Discharge: wastewater | 83,053 | 59,678 |
Discharge: user | 8 | 2,485 |
Delivery: inter-region agreement | 3,068 | 7,499 |
Total water inflows | 5,481,488 | 2,148,258 |
Water outflows | ||
Evaporation | 166,963 | 168,947 |
Outflow | 4,403,694 | 1,724,770 |
Diversions: statutory rights | 32,530 | 32,530 |
Allocation diversion: individual users | 24,927 | 42,977 |
Allocation diversion: urban system | 542,895 | 557,031 |
Total water outflows | 5,171,009 | 2,526,255 |
Balancing item—surface water | (33,583) | (72,317) |
Opening water storage | 2,388,070 | 2,838,384 |
Change in water storage | 276,896 | (450,314) |
Closing water storage | 2,664,966 | 2,388,070 |
Urban water system
Statement of Water Assets and Water Liabilities
The Statement of Water Assets and Water Liabilities presents the volume of water assets and water liabilities at the start and end of the reporting year.
Urban water system assets of the region include physical water assets (e.g. water within the urban supply, wastewater and recycled water systems) and rights or claims to water. The total net water assets are the sum of the physical water assets in the system and the water claims at the end of the reporting year (Figure N17).
Figure N17 Urban water assets and urban water liabilities for the region at 30 June 2015
Detail on the region's urban water systems assets and urban water claims for the 2014–15 year is also provided in Table N21.
2015 ML | 2014 ML | |
Water assets | ||
Supply system | 97 | – |
Wastewater | – | – |
Recycled water | – | – |
Claims: inter-region | 356 | 356 |
Claims: surface water | 0 | 0 |
Total water assets | 453 | 356 |
Opening net water assets | 356 | 356 |
Change in net water assets | 97 | 0 |
Closing net water assets | 453 | 356 |
Statement of Changes in Water Assets and Water Liabilities
The Statement of Changes in Water Assets and Water Liabilities presents the changes in water assets and water liabilities that occurred during the reporting year.
This statement is prepared on an accrual basis. Figure N18 shows the transactions that change the urban water system assets and urban water claims of the region, including:
- accrual (non-physical) transactions, indicated by the glass of water symbols
- actual water flows (both natural and engineered), indicated by the arrows.
Figure N18 Changes in urban water assets and urban water liabilities for the region during the 2014–15 year
Detail on the changes in urban water system assets and urban water claims for the 2014–15 year is also provided in Table N22.
2015 ML | 2014 ML | |
Water asset increases | ||
Wastewater collected | 547,009 | 480,243 |
Recycled water delivery: inter-region | 1,387 | 1,580 |
Claims: inter-region | 1,778 | 1,778 |
Claims: surface water | 1,040,588 | 1,040,588 |
Total water asset increases | 1,590,762 | 1,524,189 |
Water asset decreases | ||
Evaporation | 0 | 253 |
Leakage: groundwater | 37,210 | 40,390 |
Supply system delivery: urban users | 478,372 | 487,104 |
Recycled water delivery: urban users | 20,515 | 22,018 |
Supply system discharge: surface water | 0 | 0 |
Wastewater and recycled water discharge: surface water | 83,053 | 59,678 |
Discharge: sea | 443,546 | 394,499 |
Supply system transfer: inter-region | 5,332 | 4,258 |
Claims: inter-region | 1,085 | 989 |
Claims: surface water | 497,693 | 483,557 |
Other supply system decreases | 14,743 | 15,153 |
Other wastewater and recycled water system decreases | 0 | 3,756 |
Total water asset decreases | 1,581,549 | 1,511,655 |
Balancing item—urban water system | (9,116) | (12,534) |
Change in net water assets | 97 | 0 |
Statement of Water Flows
The Statement of Water Flows presents the actual water inflows and outflows associated with the water stores of the region that occurred during the reporting year.
Figure N19 shows the actual surface water flows, including flows corresponding to the accrual transactions shown in Figure N18 above (red arrows).
Figure N19 Urban water flows for the region during the 2014–15 year
Detail on the urban water system flows for the 2014–15 year is also provided in Table N23.
2015 ML | 2014 ML | |
Water inflows | ||
Wastewater collected | 547,009 | 480,243 |
Recycled water delivery: inter-region | 1,387 | 1,580 |
Delivery: inter-region agreement | 693 | 789 |
Allocated diversion: surface water | 542,895 | 557,031 |
Total water inflows | 1,091,984 | 1,039,643 |
Water outflows | ||
Evaporation | 0 | 253 |
Leakage: groundwater | 37,210 | 40,390 |
Supply system delivery: urban users | 478,372 | 487,104 |
Recycled water delivery: urban users | 20,515 | 22,018 |
Wastewater and recycled water discharge: surface water | 83,053 | 59,678 |
Discharge: sea | 443,546 | 394,499 |
Supply system transfer: inter-region | 5,332 | 4,258 |
Other supply system decreases | 14,743 | 15,153 |
Other wastewater and recycled water system decreases | 0 | 3,756 |
Total water outflows | 1,082,771 | 1,027,109 |
Balancing item—urban water system | (9,116) | (12,534) |
Opening water storage | 0 | 0 |
Change in water storage | 97 | 0 |
Closing water storage | 97 | 0 |