South East Queensland
1.1 Storages

Supporting Information

This line item represents the volume of water held in storages that are used to administer water against entitlements. The volume reported for this line item includes the volume of dead storage. Storages managed by Seqwater have no dead storage due to the installation of pump systems enabling access to the entire stored volume.

The volume reported is the sum of the volumes held in the storages in the South East Queensland (SEQ) region. Specific details of individual storages are provided in the following table.

Water storage volumes within South East Queensland region
Water resource plan (WRP) area Water supply scheme (WSS) Storage name Total storage capacity7
(ML)
 Dead storage capacity
(ML)
 30 June 2011
(ML)
 30 June 2010
(ML)
 Change in storage
(ML)
Gold Coast Nerang Advancetown Lake (Hinze Dam)1,6 310,730 0 171,128 156,098 15,030
Little Nerang Dam1 6,705 0 5,995 5,237 758
Total Gold Coast WRP area 317,435 0 177,123 161,335 15,788
Logan Basin Logan River Bromelton Off-Stream Storage4 8,210 0 8,114 8,192 –78
Cedar Grove Weir4 1,144 0 1,200 1,174 26
Lake Maroon1 44,319 0 44,319 39,492 4,827
None Tingalpa Reservoir (Leslie Harrison Dam)1 24,868 0 24,494 23,519 975
Wyaralong Dam4 102,883 0 74,469 0 74,469
Total Logan Basin WRP area 181,424 0 152,596 72,377 80,219
Moreton Central Brisbane River and Stanley River
 Mount Crosby Weir4 3,430 0 3,502 3,458 44
Lake Wivenhoe1 1,165,238 0 971,903 1,094,879 –122,976
Lake Somerset1 379,849 0 380,275 379,016 1,259
Central Lockyer Lake Clarendon1 24,276 0 24,001 4,788 19,213
Lake Dyer (Bill Gunn Dam)1 6,947 0 6,957 2,799 4,158
Cressbrook Creek Lake Cressbrook2 81,842 1,136 79,986 15,032 64,954
Lake Perseverance2 30,140 3,472 30,327 10,776 19,551
Lower Lockyer Valley Lake Atkinson (Atkinson Dam)1 30,400 0 30,444 25,398 5,046
Pine Valleys Lake Samsonvale (North Pine Dam)1 214,302 0 213,663 207,483 6,180
Warrill Valley Lake Moogerah1 86,290 0 83,023 53,185 29,838
None Enoggera Reservoir1 4,567 0 4,578 4,541 37
Gold Creek Reservoir1 1,436 0 823 785 38
Lake Kurwongbah (Sideling Creek Dam)1 14,370 0 13,684 13,018 666
Lake Manchester (Cabbage Tree Creek Dam)1 25,951 0 25,216 25,626 –410
Splityard Creek Dam3 28,700 6,400 22,300 22,300 0
Total Moreton WRP area 2,097,738 11,008 1,890,682 1,863,084 27,598
Total SEQ region 2,596,597 11,008 2,220,401 2,096,796 123,605

Notes:

  1. Data obtained from the Bureau of Meteorology's Water storages, Australia Water Resources Information System (AWRIS).
  2. Data obtained from Toowoomba Regional Council.
  3. Splityard Creek Dam volume  estimated from actual stored volume and relationship to Lake Wivenhoe.
  4. Data obtained from Seqwater. Mount Crosby Weir data from 21 June 2011 and 5 July 2010, and Wyaralong Dam data from 1 July 2011, as data were not available for the 30 June for either storage. Wyaralong Dam was not available to store water before commissioning on 11 January 2011.
  5. Beaudesert Weir was not included in the water accounting statements as information was not available on storage volumes.
  6. Advancetown Lake (Hinze Dam) stage 3 upgrade was completed in late 2011. The project raised the dam wall by approximately 15 metres and increasing storage capacity from 161,073 ML to 310,730 ML.
  7. Total storage capacity does not include flood mitigation capacity. The volume in storage may be greater than the total storage capacity if the storage was retaining flood waters or spilling at the time of measurement.

 

Quantification Approach

Data Source

Water storages, AWRIS

Provided by

Bureau of Meteorology.

Method

Storage volume is measured at the start and end of the 2010–11 year by using gauged water level height(s) in metres Australian Height Datum for individual storages. The height measurement was converted to a volume using the storage-volume curve(s) of the storage.

The storage volumes of individual storages were aggregated to present the total volume for the line item.

Assumptions, Limitations, Caveats and Approximations

Storage-volume (rating) tables are constructed from surveyed parts of the water storage, and may not reflect the storage-volume relationship across the entire storage.

 Water storages are subject to sedimentation and other physical changes over time, which affect the accuracy of the storage-volume tables.

Uncertainty Information

The uncertainty estimate was not quantified.

Comparative year

This line item corresponds to line item 1.1 Storages – entitlement system reported in the 2010 Account. There was a prior period error in the 2010 Account.

The following table compares the value at 30 June 2010 reported in the 2011 Account with the corresponding value reported in the 2010 Account for the components of this line item that changed. The total for this line item in the 2010 Account was 2,090,911 ML and the comparative year volume reported in the 2011 Account was 2,096,796 ML.

 Comparative year information – line item 1.1. Storages
2011 Account line item 2010 Account line item Storage Name Volume reported in the 2010 Account
(ML)		 Prior period error correction
(ML)		 Volume difference due to scope change
(ML)		 Restated volume reported in the 2011 Account
(ML)		 Additional information
1.1 Storages 1.1 Storages - entitlement system Lake Cressbrook 13,896 1,136 0 15,032 Dead storage not included in 2010 Account storage volume
Lake Perseverance 7,285 3,491 0 10,776 Dead storage not included in 2010 Account storage volume and minor change in volume
Mount Crosby Weir 2,200 1,258 0 3,458 Estimated storage volume revised due to actual measured data now available