South East Queensland
17.12 Surface water allocation diversion - urban water system

Supporting Information

a. Overall

This line item consists of diversions from surface water based on supplemented entitlements held by urban utilities and the South East Queensland (SEQ) Water Grid Manager. These diversions may be to water treatment plants (WTPs) that supply the SEQ Water Grid or off-grid WTPs.

A breakdown of diversions by water supply scheme (WSS) can be seen in the following table.

Allocation diversion of surface water to urban water system by water supply scheme
Water resource plan (WRP) area Water supply scheme (WSS) Volume
(ML)
Gold Coast Nerang 55,313
Total Gold Coast WRP area 55,313
Logan Basin Logan River 1,067
Total Logan Basin WRP area 1,067
Moreton Central Brisbane River and Stanley River
115,752
Central Lockyer 0
Cressbrook Creek 208
Lower Lockyer Valley 0
Pine Valleys 24,571
Warrill Valley 417
Total Moreton WRP area 140,948
Total SEQ region 197,328

Notes:

  1. All allocations within the Cressbrook Creek WSS are assumed to be urban.
  2. Line item 17.21 Other surface water decrease and line item 13.2 Adjustment and forfeiture of surface water allocation – urban water system include the component of the diversions from the Cressbrook Creek WSS that was transferred out of the region to Toowoomba. This line item only includes the component that was not transferred out of the region.

b. Urban surface water allocation remaining – reconciliation

The following table shows the urban surface water allocation reconciliation. Due to the very wet year, demand was lower than in previous years and combined with the 100% allocation announcements, this has resulted in a higher forfeiture of urban surface water allocation (around 58%).

Urban surface water entitlements have a component included within them to allow for some future population growth. A component of the forfeiture may be attributed to this reason.

Urban surface water allocation reconciliation table
Water resource plan (WRP) area Water supply scheme (WSS)

Line item 5.2

Line item 21.2

Line item 17.12

Line item 13.2

Line item 5.2

Opening balance
(ML)
Announcement (ML) Allocation diversion
(ML)
Adjustment and forfeiture (ML) Closing balance (ML)
Gold Coast Nerang 0 83,995 55,313 28,682 0
Total Gold Coast WRP area 0 83,995 55,313 28,682 0
Logan Basin Logan River 0 8,910 1,067 7,843 0
Total Logan Basin WRP area 0 8,910 1,067 7,843 0
Moreton Central Brisbane River and Stanley River 0 278,725 115,752 162,973 0
Central Lockyer 0 0 0 0 0
Cressbrook Creek 0 10,000 208 9,792 0
Lower Lockyer Valley 0 0 0 0 0
Pine Valleys 0 59,000 24,571 34,429 0
Warrill Valley 0 2,196 417 1,779 0
Total Moreton WRP area 0 349,921 140,948 208,973 0
Total SEQ region 0 442,826 197,328 245,498 0

c. Urban entitlements

For the purpose of the 2011 Account, urban claim on surface water only includes the SEQ Water Grid Manager and Toowoomba Regional Council entitlement allocations, as they have been identified as the urban holders of entitlements in the resource operation plans (ROPs).

Other organisations may hold supplemented entitlements for some form of urban use, but, as urban use is not identified on entitlements, these could not readily be identified. For this reason, a small number of entitlements that may fall into this category are included in line item 21.1 Surface water allocation announcements.

In Queensland, entitlements and allocations do not have intended use as an attribute, and all metered abstractions do not have entitlement priority or use as attributes. Urban holders of entitlements were individually determined by obtaining all entitlement volumes from the Gold Coast, Logan Basin and Moreton ROPs schedule of water allocations listed for the SEQ Water Grid Manager and Toowoomba Regional Council.

Quantification Approach

Data Source

Queensland Department of Environment and Resource Management (DERM), Water Management System (WMS) database.

Provided by

DERM.

Method

Supplemented allocation diversions were provided by DERM from the WMS database for each water resource plan area. The current ROP reporting requirements do not allow for reporting by 'type' of use. This line item was calculated by extracting the urban diversions from the total supplemented allocation diversion.

Assumptions, Limitations, Caveats and Approximations

DERM has accepted metered data provided by WSS operators in good faith. The volume calculated excludes distribution loss, which was included in line item 13.2 Adjustment and forfeiture of surface water allocation – urban water system.

Uncertainty Information

Derived from measured data. DERM reliability and accuracy rating is A2.

Comparative year

This line item corresponds to line item 19.8.2 Allocation diversion of regulated flows – High security, Urban holders reported in the 2010 Account. The provision of data on which WTP utilised supplemented and unsupplemented entitlements was obtained for the 2011 Account from Seqwater. This showed that the entitlement type has no direct linkage to the WTP forming part of the SEQ Water Grid and identified a number of WTP listed as supplemented that were in fact unsupplemented (and vice versa). In addition to this, data for a number of WTP were not available for the 2010 Account but were available for the 2011 Account.

This has resulted in the numbers between the two years not being comparable due to additional WTP data and a re-allocation of WTP between this line item and line item 11.2 Non-allocation diversion of surface water to urban water system. As data were not available to completely rectify the volumes presented in the 2010 Account, the 2011 Account comparison year used the data reported in the 2010 Account (175,727 ML) and it is noted that direct comparisons should not be made between the volumes.