South East Queensland: Water stores
Relatively poor rainfall conditions for most of the year contributed to low runoff across the region and a drop in storage volumes. Surface water diversion and groundwater extraction both remained similar to last 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
| 2017 ML |
2016 ML |
|
| Opening surface water store | 2,213,337 | 2,564,345 |
| Inflows | 3,706,004 | 1,889,976 |
| Outflows | (3,813,172) | (2,226,819) |
| Balancing item | (72,326) | (14,165) |
| Closing surface water store | 2,033,812 | 2,213,337 |
- The volume of surface water in the region decreased from 2,213,337 ML at 1 July 2016 to 2,033,812 ML at 30 June 2017.
- The balancing item of -72,236 ML is approximately 4% of the closing surface water store. This difference is primarily due to uncertainties associated with the runoff estimate.
Surface water flows
Figure S3 Water inflows and outflows for South East Queensland's surface water store during the 2016–17 year
- The largest natural water flows were runoff and river outflow, which were both much higher than the previous year, primarily reflecting the record high March rainfall conditions experienced across the region, despite dry conditions otherwise (see Climate and water).
Figure S4 Surface water diversions during the 2016–17 year in the South East Queensland region's water plan areas
- Total surface water diverted in the region was 360,198 ML, an 11% increase from the previous year. This increase primarily reflects improvements in urban water reporting rather than an actual increase in demand. Improvements introduced this year allow for the accounting of raw water delivered to customers, which could not be reported in previous years.
- More than 91% of the total diversion was for the urban system, with 7% supplied to individual users.
- The remaining 2% of the total diversion comprised non-allocated diversion: individual users, non-allocated diversion: urban system and other statutory rights.
- For a more detailed description of the water usage in the region, and the associated entitlements, see the Surface water rights note.
Groundwater store
| 2017 ML |
2016 ML |
|
| Opening groundwater store | 11,115 | 11,115 |
| Inflows | 25,416 | 25,513 |
| Outflows | (17,515) | (17,770) |
| Balancing item | (7,901) | (7,743) |
| Closing groundwater store | 11,115 | 11,115 |
- The volume of groundwater in the region is equivalent to the permissible consumptive volume, which is the legal extractable limit and, therefore, remains unchanged from year to year.
- The balancing item of -7,901 ML is primarily due to the assumption of constant volume in the groundwater store.
Groundwater flows
Figure S5 Water inflows and outflows for South East Queensland's groundwater store during the 2016–17 year
- Natural groundwater movement across the region boundary is considered to occur within the region; however, these flows could not be quantified.
- Total groundwater extracted in the region was 17,515 ML, a marginal decrease from the previous year.
- Non-allocated extractions: urban system made up approximately 45% of the total extraction; while allocated extraction: individual users and non-allocated extraction: individual users accounted for approximately 32% and 23% of the total extraction, respectively.
- For a more detailed description of the water usage in the region and the associated entitlements, see the Groundwater rights note.
Urban water system
| 2017 ML |
2016 ML |
|
| Opening urban water system | 0 | 0 |
| Inflows | 593,036 | 545,851 |
| Outflows | (601,208) | (544,880) |
| Balancing item | 8,172 | (971) |
| Closing urban water system | 0 | 0 |
- The volume of water in the region's urban 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 attributed to metering inaccuracies, unaccounted losses, and uncertainties in the estimation of certain volumes (see Methods).
Urban water system flows
Figure S6 Water inflows and outflows for the South East Queensland's urban water system during the 2016–17 year
- A detailed breakdown of the inflows and outflows of the urban water system components is provided in the urban water balance diagram.
Water supply inflows
Figure S7 Water sources used in South East Queensland's urban water system during the 2016–17 year compared with the previous six years
- Surface water made up 97% of urban supply, while groundwater and desalinated water made up approximately 2% and 0.5% of urban supply, respectively.
- Total urban supply was 341,966 ML, a 14% increase from last year. This increase primarily reflects improvements in urban water reporting rather than an actual increase in demand. Improvements introduced this year allow for the accounting of raw water delivered to customers, which could not be reported in previous years.
Wastewater and recycled water inflows
- Wastewater collected was 251,070 ML during the 2016–17 year.
Water supply outflows
Figure S8 Outflows from the water supply system
- The majority of water supply outflow was delivery to urban users.
- 10% of the total outflow from the urban supply system was related to losses.
Wastewater and recycled water system outflows
Figure S9 Outflows from the wastewater and recycled water systems
- Approximately 8% of the treated wastewater was recycled and delivered to urban users.
- Most of the remaining treated wastewater was discharged to the sea.