Bureau Home » Water Information » National Water Account » 2021 Account » Adelaide » Supporting information » Supporting information

Adelaide: Supporting information

  • Dry conditions contributed to low runoff and streamflow across the region.
  • End-of-year storage was only slightly less than last year.
  • 37% of the allocated water was taken in 2020–21, mostly for residential and agricultural purposes.

Schematic representation of the Adelaide region. In 2020–21, runoff was 38% less than average. Storage volumes at 30 June 2021 were 48% full, slightly lower than the previous year. 34% of the total surface water allocation (158 GL) was taken. 43% of the total groundwater allocation (109 GL) was taken.

For further information on the region's water accounting statements scroll down this page or click on the links below:

 

Water assets

Kangaroo Creek Reservoir, Adelaide region (Bureau of Meteorology © SA Office)

 

Surface water assets

  • Surface water asset volumes in the region at 30 June 2021 were 95 GL, more than 99% of which is water held in storages. The remaining amount is water held in rivers.

 

Bar graph of annual storage volume in the Adelaide region at 30 June for the years 2010–2021. Accessible storage plus dead storage is plotted against the storage capacity to show percentage full at 30 June each year. Storages at 30 June 2021 were 48% full, slightly lower than the previous year. Since 2010, the highest end-of-year storage volume was in 2011 when storages were 69% full, the lowest was in 2013 when storages were 44% full.
Figure S1 Total storage volume in the region at 30 June 2021 compared with the previous 10 years

 

  • Storage volumes decreased slightly from 50% full at 30 June 2020 to 48% full at 30 June 2021.

 

Map of Adelaide region showing the status of each storage at 30 June 2021. The storages are colour coded into ten categories of volume as a proportion of capacity. Myponga, Happy Valley, Hope Valley, Barossa, and Warren storages were over 80% full. Mount Bold, South Para, Kangaroo Creek, Millbrook, and Little Para storages were less than 50% full. An inset line graph shows the time series of percentage-full storage volume between 1 July 2013–30 June 2021. Adelaide storages at 30 June 2021 were 50% full, slightly more than last year.
Figure S2 Percentage-full volume on 30 June 2021 for each storage and total storage volume from 2013–2021 (inset)

 

  • Storage volumes peaked during mid-October 2020 at 73% full following rainfall during the winter–spring months.
  • Despite the below-average rainfall conditions for most of the year, storage volumes at 30 June 2021 were only slightly less that at the same time last year, largely due to the average to above-average rainfall across the region in September–October 2020.
  • More detailed information on the individual storages within the region is available on the Bureau of Meteorology's Water Storage website.

 

Groundwater assets

  • The groundwater asset represents the extraction limits associated with the region's aquifers. This volume does not change from year to year unless a water allocation plan is amended.

 

Water liabilities

Sturt Mitigation Dam, Adelaide region (Bureau of Meteorology © SA Office)

 

  • Water liabilities in the Adelaide region refer to the volume of allocation remaining on licence entitlements at the end of the 2020–21 year.

 

Table S1 Volume of surface water allocation remaining at 30 June 2021
Description Individual users (ML) Urban system (ML)
  Opening balance at 1 July 2020 622 0
add Allocation 14,768 143,045
less Allocated diversion 2,713 50,323
less Adjustment and forfeiture 11,698 92,722
  Closing balance at 30 June 2021 979 0

 

Table S2 Volume of groundwater allocation remaining at 30 June 2021
Description Individual users (ML)
  Opening balance at 1 July 2020 9,289
add Allocation 109,110
less Allocated extraction 46,499
less Adjustment and forfeiture 65,845
  Closing balance at 30 June 2021 6,055

 

  • The surface water licences in the Adelaide region have a management year that ends on 30 June.
  • The Barossa Prescribed Water Resources Area licensees for the North Para River and tributaries may carry over the unused portion of their allocation.
  • A more detailed description of water allocations in the Adelaide region is given in the Water use section below.

 

Water flows

Onkaparinga River mouth, Adelaide region (istock © anonymous)

 

Figure S3 Water inflows and outflows for the region's water stores and systems during the 2020–21 year

 

  • Total surface water flows into the region's storages was 346 GL. A key item contributing to surface water inflows was runoff, which made up 37% of the total surface water inflows.
  • For the third consecutive year, runoff was much lower than average (based on modelled data from 1971–2021) due to relatively poor rainfall across the region.
  • A key item contributing to surface water outflows from the region's storages was river outflow from the region, which made up 33% of the total surface water outflows. River outflow was well below average due to the dry conditions and low runoff across the region throughout most of the year.
  • Water taken from surface water and groundwater resources for consumptive use was 212 GL, around 48% of the total surface water and groundwater outflow (see Water use section below).

 

Water availability

Bar graph of annual surface water availability in the Adelaide region for the years 2011–2021. Storage at 1 July plus estimated inflows during the year is plotted against the mean water availability (based on 1971–2021 data). Surface water available during 2020–21 was below average for the third consecutive year. Water availability was well above average during 2011–12 and 2016–17.
Figure S4 Annual surface water available in the Adelaide region, 2011–12 to 2020–21

 

  • Physical surface water availability is calculated as the sum of storage at the start of the year (see Water assets) and estimated inflows into storages and rivers during the year (see Figure S3).
  • Surface water availability in the Adelaide region in 2020–21 was below average for the third consecutive year.
  • Water taken during the year is influenced by the physical water availability. Typically, water taken from surface water resources is low when water availability is low. This is discussed in more detail in the Water use section below.

 

Water use

City of Adelaide, Torrens River, South Australia (CSIRO © Willem van Aken)

 

Figure S5 Water taken during the 2020–21 year in the region's water resource areas

 

  • Total surface water diverted in the region was 166 GL.
  • 98% of the total surface water diversion was for urban supply (comprising allocated and non-allocated diversions) while 2% was for individual users.
  • The non-allocated water diversion to the urban system comprises water that was imported from the River Murray and stored within the region's storages. Most of these diversions were from the Happy Valley and Hope Valley reservoirs, located outside of the region's prescribed water resource areas.
  • Total groundwater extracted in the region was 47 GL.
  • More than 99% of the groundwater extraction was for individual users; less than 1% was for the irrigation scheme.

 

Bar graph of annual surface water allocation and diversion for different users in the Adelaide region from 2012–13 to 2020–21. Most of the surface water allocations are associated with the urban system. These allocations change little from year to year. In 2020–21, 35% of the allocation for the urban system was taken, higher than the previous year. 18% of the allocation for individual users was taken. Non-allocated surface water is also taken for the urban system.
Figure S6 Surface water allocations and diversions in the Adelaide region for the years ending 30 June, from 2013–2021

 

  • In 2020–21, total surface water allocation was 158 GL, mostly for urban system supply. 34% of the allocated surface water was taken.
  • Allocated diversion to the urban system was much higher compared to the previous two years. The lower surface water supply over the last three years was influenced by SA Water opting to reduce pressure on its surface water resources and increase its reliance on non-allocated diversions to the urban system, as well as desalinated water supply (see Urban system supply below).

 

Bar graph of annual groundwater allocation and extraction for different users in the Adelaide region from 2012–13 to 2020–21. All the groundwater allocations are associated with individual users. The allocation in 2020–21 was same as the previous year. In 2020–21, 43% of the allocation for individual users was taken, lower than the previous year. Non-allocated groundwater is also taken for the irrigation scheme and other statutory rights.
Figure S7 Groundwater allocations and extractions in the Adelaide region for the years ending 30 June, from 2013–2021

 

  • Total groundwater allocation was 109 GL, mostly for individual users for agricultural use. 43% of the allocated groundwater was taken.
  • Groundwater extraction for individual users remained the same as last year. This was likely influenced by the improved rainfall conditions during Autumn 2020, which meant there was higher surface water availability for consumptive use during the year.

 

Urban system supply

Stacked bar graph showing the annual water sourced for Adelaide region's urban supply system during the period from 2010–11 to 2020–21. Each bar in the stack progressively represents surface water, inter-region inflow, and desalinated water. Since 2010–11, total water sourced for the urban system has been relatively consistent. Surface water and inter-region inflows are the predominant water sources. Key aspects of the graph are described in the text below the figure.
Figure S8 Water sources used in Adelaide's urban supply system during the 2020–21 year compared with the previous nine years

 

  • Total inflow to the urban supply system was 168 GL, similar to the previous year.
  • 97% of the total urban supply was from surface water diversions—allocated and non-allocated. The non-allocated diversions to the urban system comprise water that was imported from the River Murray and stored within the region's storages. Inter-region water from the River Murray made up 67% of the total urban supply.
  • Desalinated water made up only 3% of urban supply, much lower than the previous year. More surface water availability during the year decreased the reliance on desalinated water to meet urban demand.

 

Water market activity

Irrigation, Adelaide region (iStock © Phillip Minnis)

 

  • Most of the water trade in the region is related to groundwater. In 2020–21, 561 ML of groundwater allocations and 5,133 ML of groundwater entitlements were traded.
  • In terms of surface water, 967 ML of entitlements were traded during the year.
  • For more information on water markets in the region, see the Bureau of Meteorology's Water Market Dashboard.

 

Environmental water

Murray River, South Australia (istock © Robyn Brody)

 

Planned unregulated surface water

Environmental water provisions

  • Environmental water provisions are defined for rivers in the Barossa and Western Mount Lofty Ranges prescribed water resource areas to maintain the rivers' natural ecological processes.
  • More detailed descriptions of the environmental water provisions in these areas are provided in section 2 of the Barossa and Western Mount Lofty Ranges water allocations plans.

 

Environmental water outcomes

  • One example of the environmental water outcomes relating to the North Para River within the Barossa Prescribed Water Resource Area is highlighted below.

 

Line graph of daily flow in 2020–21 in the North Para River at Yaldara, station number A5050502. The flow is compared with the required environmental water provisions, including the freshet (1.4 ML/day), pool connection (330 ML/day), mid flow maintenance (1,520 ML/day), and overbank flow (4,650 ML/day). Key aspects of the daily flow graph are described in the text below the figure.
Figure S9 Daily flow in the North Para river compared with the required flow regime during the 2020–21 year

 

  • In 2020–21, streamflow in the North Para River at Yaldara (Station A5050502) exceeded the freshet flow threshold throughout most of July–October 2020, and the latter half of June 2021.
  • Streamflow did not reach the freshet flow threshold on any day during the 6-month period between December 2020–May 2021 due to the dry conditions across the region.
  • Streamflow was well below the pool connection and mid-flow maintenance flow thresholds in 2020–21 for the fourth successive year.

 

Planned partly regulated surface water

Environmental water provisions

  • Environmental water requirements are defined within the Western Mount Lofty Ranges Prescribed Water Resource Area for the operational release of water from storages to control or influence streamflows.
  • Information on the volume of water released during 2020–21 was not available prior to the publication of this account.