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National Water Account 2016

Adelaide: Statement details

While total rainfall across the region was slightly higher than the previous year, several years of dry conditions in the Adelaide region have depleted soil moisture stores, leading to a decline in natural inflows to both the groundwater and surface water stores. Aquifer storage declined for the third consecutive year. Surface water storages increased by 4% during the 2015–16 year, primarily due to increased transfers from the River Murray.


 

Water assets

Surface water assets

Surface water asset volumes in the Adelaide region at 30 June 2016 were 103,300 ML, representing the volume of water held in storages. The location of each storage within the Adelaide region and the volume of water in each storage (including dead storage) as a percentage of total storage capacity at the end of the 2015–16 year is shown in Figure S1.

The volume of water in rivers, lakes and wetlands could not be quantified due to a lack of available data; however, the volume of water held in channels and lakes is considered to be relatively small compared to the volume held in storages.

Surface water asset volumes also include an inter-region claim to River Murray water. The claim is facilitated by a Class 6 water access entitlement held by SA Water to 130,000 shares in the River Murray. Unused water remaining at the end of the year is forfeited as entitlement conditions do not allow carryover of unused water, resulting in a closing balance of zero for the surface water claim on inter-region water.

 

Figure S1 Percentage-full volume on 30 June 2016 for each storage
Figure S1 Percentage-full volume on 30 June 2016 for each storage
 

 
Overall, surface water storage in the Adelaide region increased slightly in the 2015–16 year from 48% of capacity to 52% of capacity. Although the region experienced over 100mm more rainfall than the 2014–15 year (see Climate and water) this is still below average rainfall conditions, and the dry soil moisture conditions reduced natural inflows to surface water storages. Despite a decline in natural inflows into storages, surface water storage volumes in the Adelaide region increased during the 2015–16 year due to water transfers from the River Murray.

Total surface water storage volume at 30 June 2016 compared with the previous five years is given in Figure S2.

 

Figure S2 Total storage volume in the region at 30 June 2016 compared with the previous 5 years
Figure S2 Total storage volume in the region at 30 June 2016 compared with the previous five years
 

 

Groundwater assets

Groundwater asset volumes in the Adelaide region at 30 June 2016 were 86,356 ML. While information exists on water movement to and from the aquifers (see Groundwater store note), volumes of water stored in the aquifers could not be quantified.

The volume reported as the groundwater asset refers to the managed groundwater volume reported in the relevant water allocation plans. The managed aquifer volume includes groundwater extraction limits and the non-licensed groundwater extractions described by each water allocation plan. It does not change from year to year, unless the water allocation plan is amended.

Information on the total annual change in aquifer storage volume was available, which provides an indication of whether groundwater levels in the region's aquifers were increasing or decreasing. Figure S3 shows the annual change in aquifer storage since 2012. Aquifer storage during the 2015–16 year decreased for the third successive year. This decrease reflects the relatively poor rainfall experienced across the region over the last three years, leading to reduced recharge, as well as increased demand for groundwater (see Water flows).

 

Figure S3 Total change in aquifer volume in the region at 30 June 2016 compared with the previous five years
Figure S3 Total change in aquifer volume in the region at 30 June 2016 compared with the previous four years

 

Irrigation scheme assets

Irrigation scheme asset volumes include an inter-region claim to River Murray water. The claim is facilitated by a Class 3a water access entitlement held by Barossa Infrastructure Limited to shares in the River Murray. Unused water remaining at the end of the year is forfeited as entitlement conditions do not allow carryover of unused water, resulting in a closing balance of zero for the irrigation scheme claim on inter-region water.

 

Water liabilities

Water liabilities in the Adelaide region refer to the volume of allocation remaining on licence entitlements at the end of the 2015–16 year for:

  • surface water: individual users—377 ML
  • groundwater: individual users—9,088 ML.

The surface water licences in the Adelaide region have a management year which ends on 30 June. In the Barossa Prescribed Water Resources Area, licensees for the North Para River and tributaries may carry over the unused portion of their allocation up to a maximum of 30% of the annual allocation; at the end of 2015–16, this volume was 377 ML. Carryover is not permitted in the Little Para Prescribed Water Course (Adelaide and Mount Lofty Ranges Natural Resources Management Board 2013).

The total volume of groundwater allocation remaining at the end of the 2015–16 year was 9,088 ML. This is made up of 6,039 ML of recharged water credits in the Northern Adelaide Plains Prescribed Water Area and 3,049 ML of groundwater allocation carryover; 578 ML from the Barossa Prescribed Water Resources Area; 1,219 ML from the McLaren Vale Prescribed Water Area; and 1,252 ML from Western Mount Lofty Ranges Prescribed Water Resources Area.

The allocation remaining for each licence entitlement from the water accounting statements is provided in tables S1–S2.

A more detailed description of water allocations and associated water rights in the Adelaide region is given in the Water rights note.

 

Table S1 Volume of surface water allocation remaining at 30 June 2016
 Individual users
(ML)
Opening balance at 1 July 2015614
Allocation8,659
Allocated diversion(3,970)
Adjustment and forfeiture 4,926
Closing balance at 30 June 2016 377

 

Table S2 Volume of groundwater allocation remaining at 30 June 2016
 Individual users
(ML)
Opening balance at 1 July 20157,321
Allocation103,651
Allocated extraction56,040
Adjustment and forfeiture 45,844
Closing balance at 30 June 2016 9,088

 

Water asset increases

 Total water asset increases for the region were 541,062 ML and comprised:

  • surface water increases—322,740 ML
  • groundwater increases—105,364 ML
  • urban water system—103,323 ML
  • irrigation scheme increases—9,635 ML

The key water asset increases for the region were runoff and SA Water's inter-region claim for the River Murray (surface water increases).

Runoff is climate-dependant and comprised 27% of all water asset increases. This represents a 29% decrease compared to the previous year and reflects the continuing dry conditions experienced across Adelaide over the last three years (see Climate and water).

SA Water's Class 6 water access entitlement on the River Murray increased by 11% from the previous year due to the utility making use of its '5-year rolling average' arrangement. The total water access entitlement for the River Murray is 650,000 ML over five years, with the nominal allocation being 130,000 ML/year. As SA Water did not access the full 650,000 ML in the previous five years, it was credited an additional 15,000 ML adjustment to the annual nominal allocation.

Groundwater increases primarily represent recharge: landscape at 100,839 ML. This was 75% less than the volume reported for 2014–15. 

Urban water system increases comprised wastewater collected and delivery: desalinated water. The volume of wastewater collected within the Adelaide region has changed little over the years; however, desalinated water has fluctuated due to the initial commissioning and testing of the Adelaide Desalination Plant (see Urban water store note).

Barossa Infrastructure Limited's inter-region claim on the River Murray made up 94% of all irrigation scheme increases, with the remaining being water sourced from community wastewater management schemes.

 

Water asset decreases

Total water asset decreases for the region were and 335,966 ML and comprised:

  • surface water decreases—90,571 ML
  • groundwater decreases—2,418 ML
  • urban water system decreases—213,904 ML
  • irrigation scheme decreases—29,073 ML

The key water asset decrease was the supply system delivery: urban users (urban water decrease). It made up 43% of all water asset decreases in the Adelaide region. River outflow was the second largest water asset decrease and made up the majority of surface water asset decreases.

Groundwater asset decreases were substantially less than the previous year due to the lack of a proper estimation for groundwater discharge: landscape. This made up 99% of all groundwater decreases in 2014–15. Both climate-dependant inter-region outflow and inter-region coastal outflow were similar to the previous year.

The urban water system as a whole contributed the most to all water asset decreases. Supply system delivery: urban users made up the majority (63%) of urban water system decreases. Treated wastewater discharge: sea contributed 24% to urban water system decreases. Recycled water delivery: urban users contributed 3% and increased slightly from the previous year.

Irrigation water delivered to customers increased by 7% from the previous year.

 

Water flows

Total water inflows were 535,948 ML and total water outflows were 390,862 ML. These are different from the volumes reported as the total Water asset increases and the total Water asset decreases. The volume of water flows includes the flows corresponding to the accrual transactions; that is, the allocation volume for a claim is reported as a water asset and the allocated water diversions and extractions are reported within the total water flows.

A detailed description on all the water inflows associated with the surface water store, groundwater store, urban water system and irrigation scheme are provided in the Water stores note.

 

Unaccounted-for difference

 The volume recognised in the water accounting statements, 136,555 ML, represents the total unaccounted-for difference for the Adelaide region for the 2015–16 year.

The unaccounted–for difference is the volume necessary to reconcile the opening water storage and closing water storage with the total water inflows and total water outflows reported in the water accounting statements. It is calculated according to Table S3.

 

Table S3 Calculation of unaccounted-for difference for the 2015–16 year
 Volume
ML
Opening water storage balance at 1 July 2015181,125
Total inflows535,948
Total outflows(390,862)
Closing water storage balance at 30 June 2016(189,656)
Unaccounted-for difference136,555

 

Table S4 shows that the unaccounted-for difference is primarily explained by the balancing item of the surface water store. The surface water store balancing item is mainly attributed to uncertainty with runoff and river outflow as well as the volume of river and floodplain losses not being able to be quantified.

The unaccounted–for difference can also be calculated by adding the volumes necessary to reconcile (balance) the opening and closing storage with the water inflows and outflows of each of the separate water stores of the region, as shown in Table S4.

Table S4 Balancing volumes for the water stores of the Adelaide region for the 2015–16 year
 Volume
ML
Surface water store144,471
Groundwater store(11,545)
Urban water system1,563
Irrigation scheme 2,066
Unaccounted-for difference136,555