Adelaide: Water stores
- Below-average rainfall during most of the year contributed to relatively low runoff across the region and a decrease in surface water storage.
- The decrease in the region's surface water availability meant there was an increased reliance on inter-region transfers from the River Murray for urban water supply.
For a water balance on each of the region's water stores for the 2017–18 year scroll down this page or click on the links below:
Surface water store
| Description | Volume (ML) | |
| Opening surface water store | 111,177 | |
| add | Inflows | 413,790 |
| less | Outflows | 434,977 |
| add | Balancing item | 2,409 |
| Closing surface water store | 92,399 | |
- The volume of surface water in the region decreased from 111,177 ML at 1 July 2017 to 92,399 ML at 30 June 2018.
- The balancing item is primarily attributed to uncertainties associated with the runoff estimate (see Methods).
Surface water flows
Figure S4 Water inflows and outflows for the surface water store during the 2017–18 year
- The largest natural water flows were runoff and outflow. Both were below average compared to previous years, and much lower than last year when well above-average rainfall was experienced across the region (see the 2017 Account).
- The transfer of water into the region (delivery: inter-region) from the River Murray doubled from last year due to the decrease in the region's surface water availability.
Figure S5 Allocated surface water diversions during the 2017–18 year in the region's allocation areas
- Total allocated surface water diversion was 109,310 ML, which is around 68% of the total surface water diverted across the region.
- Approximately 97% of the total allocated surface water diversion was for urban supply, all of which was from the Western Mount Lofty Ranges Prescribed Water Resources Area.
- 3% of the total allocated diversion was for individual users.
- For a more detailed description of the water usage in the region, and the associated entitlements, see the Surface water rights note.
Groundwater store
| Description | Volume (ML) | |
| Opening groundwater store | 86,356 | |
| add | Inflows | 93,825 |
| less | Outflows | 137,870 |
| add | Balancing item | 44,045 |
| Closing groundwater store | 86,356 | |
- The volume of groundwater in the region is equivalent to the managed aquifer volume, which is the legal extractable limit and, therefore, remains unchanged from year to year.
- The balancing item is primarily attributed to uncertainties associated with the groundwater recharge and discharge estimates (see Methods).
Groundwater flows
Figure S6 Water inflows and outflows for the groundwater store during the 2017–18 year
- The largest groundwater flow in the region is recharge: landscape, which makes up 82% of the total groundwater inflows.
- Recharge from landscape was less than last year, reflecting the relatively poor rainfall and streamflow conditions across the region throughout most of the year (see Climate and water).
Figure S7 Groundwater extractions for the Adelaide region during the 2017–18 year by allocation area
- Total allocated groundwater extraction in the region was 53,793 ML.
- More than 80% of the allocated groundwater extraction occurred in the Western Mount Lofty Ranges and Northern Adelaide Plains allocation areas.
- All allocated extraction in the region is for individual users; the urban water system does not access groundwater in the Adelaide region.
- For a more detailed description of the water usage in the region and the associated entitlements, see the Groundwater rights note.
Urban water system
| Description | Volume (ML) | |
| Opening urban water store | – | |
| add | Inflows | 262,380 |
| less | Outflows | 260,410 |
| add | Balancing item | (1,970) |
| Closing urban water store | – | |
- The volume of water in the region's urban water system comprises water in the pipe network. As no major pipe network changes were made, this volume is assumed to remain unchanged throughout the year.
- The balancing item is likely attributed to metering inaccuracies, unaccounted losses, and uncertainties in the estimation of certain volumes (see Methods). The balancing item in the urban system is generally relatively small as the system is a closed system.
Urban water system flows
Figure S8 Water inflows and outflows for the urban water system during the 2017–18 year
Water supply inflows
Figure S9 Water sources used in Adelaide's urban supply system during the 2017–18 year compared with the previous seven years
- Total inflow to the urban supply system was 161,577 ML, a 12% increase from the previous year. This increase was driven principally by an increase in customer reliance on water from the urban system in response to the below-average rainfall across the region during the year, particularly during the summer period.
- Surface water diversion made up 66% of the total urban supply, much less than the 87% contribution last year. The below-average rainfall conditions during most of the year meant there was less surface water available to meet demand.
- Inter-region water supply from the River Murray made up more than 32% of the total urban supply, compared to 10% last year. The decrease in the region's surface water availability meant there was more reliance on inter-region transfers for urban water supply.
- Desalinated water made up 3% of urban supply, similar to last year.
Wastewater and recycled water inflows
- Wastewater collected was 100,803 ML during the 2017–18 year.
Water supply outflows
Figure S10 Outflows from the water supply system
- The majority of water supply outflow was supply system delivery: urban users.
- Approximately 8% of the total outflow from the urban supply system was related to losses.
Wastewater and recycled water system outflows
Figure S11 Outflows from the wastewater and recycled water system
- Approximately 28% of the treated wastewater was recycled, including recycled water delivery: irrigation and recycled water delivery: urban users.
- Most of the remaining treated wastewater was discharge: sea.
Irrigation water
- The Adelaide region's irrigation scheme is represented by three individual systems: Barossa Infrastructure Limited, Willunga Basin Water Company, and the Virginia Pipeline Scheme.
| Description | Volume (ML) | |
| Opening surface water store | – | |
| add | Inflows | 35,943 |
| less | Outflows | 31,853 |
| add | Balancing item | (4,090) |
| Closing surface water store | – | |
- The volume of water in the region's irrigation system comprises water in the channel network. As no major changes were made to this network, this volume is assumed to remain unchanged throughout the year.
- The balancing item may be due to a number of factors, such as metering inaccuracies and unaccounted losses (see Methods). The balancing item in the irrigation system is generally relatively small as it is relatively contained.
Irrigation scheme flows
Figure S12 Water inflows and outflows for the irrigation scheme during the 2017–18 year
- Total inflow to the irrigation scheme was 35,943 ML, a 72% increase from last year.
- The increase in water supply for irrigation is attributed to the drier conditions across the region throughout most of the year (see Climate and water).
- Delivery: recycled water from the region's urban wastewater system made up 57% of the total supply.