Sydney

                                                                                                   

1.1 Storages—entitlement system

                             

Supporting information   


The following tables provide a summary and breakdown of information on storage entitlement system in the Sydney region.

 

Volumes for storage reservoirs—summary
Storage reservoir Total capacity (ML) Dead storage volume (ML) Volume (ML) 30 June 2009 Volume (ML) 30 June 2010
All 2,864,582 Not available* 1,811,667** 1,708,184**

* See the following two tables for details

** Includes dead storage volume

 

Breakdown of storage volumes at the beginning and end of 2009–10 for storage reservoirs managed by the Sydney Catchment Authority
Storage reservoir Total capacity (ML) Dead storage volume (ML) Volume* (ML) 30 June 2009 Volume* (ML) 30 June 2010

Cataract

 97,370 3,070 87,030 64,730

Cordeaux

 93,640 0 61,400 51,230

Avon

 214,400 67,700 173,720 153,440

Nepean

 69,810 0 41,510 58,280

Woronora

 71,790 0 39,350 25,960

Lake Burragorang (Warragamba Dam)

 2,031,000 4,000 1,177,860 1,126,830

Prospect

 48,200 14,900 46,230 45,310

Wingecarribee

 25,880 1,780 18,680 20,120

Fitzroy Falls

 22,920 12,920 21,490 22,320

Lake Yarrunga (Tallowa Dam)

 90,000 54,700 90,000 90,000

Blue Mountains**

 2,790 0 2,450 2,350

Total

 2,767,800 159,070 1,759,720 1,660,570

* Includes dead storage volume

** Blue Mountains storage reservoirs include Medlow Reservoir, Greaves Creek Reservoir, Upper Cascade Reservoir, Middle Cascade Reservoir and Lower Cascade Reservoir.

 

Breakdown of storage volumes at the beginning and end of 2009–10 for storage reservoirs not managed by the Sydney Catchment Authority
Storage reservoir Managing authority Total capacity (ML) Dead storage volume (ML) Volume* (ML) 30 June 2009 Volume* (ML) 30 June 2010
Lake Lyell Delta Electricity 34,192 2,083 15,092 10,956
Lake Wallace Delta Electricity 4,004 1,798 3,852 3,665
Thomsons Creek Dam Delta Electricity 27,500 0 10,464 9,665
Pejar Goulburn Mulwaree Council 9,000 90 2,284 2,732
Sooley Goulburn Mulwaree Council 6,250 300 4,950 5,771
Farmers Creek No. 2 Lithgow City Council 450 Not available 450 415
Bamarang Shoalhaven City Council 3,800 100 3,700 3,225
Danjera Shoalhaven City Council 7,800 2,300 7,660 7,660
Flat Rock Creek Shoalhaven City Council 570 0 309 309
Bundanoon Wingecarribee Shire Council 1,170 Not available 1,140 1,170
Medway Wingecarribee Shire Council 2,046 Not available 2,046 2,046
Total 96,782 Not available 51,947 47,614

* Includes dead storage volume

Shoalhaven City Council pumps its entitled water from the Shoalhaven River (diverted from Lake Yarrunga) at the Burrier pumping station. Bamarang and Flat Rock Creek reservoirs receive water pumped from Burrier. In addition to this water, these two reservoirs have their own natural run-off. During 2009–10, all water received from the Burrier pumping station was released to water treatment plants. Therefore, volumes shown in the above table do not include water pumped from Burrier.
Water from Danjera Reservoir is diverted to water treatment plants when there is insufficient diversion from Lake Yarrunga (Tallowa Dam) for pumping at Burrier. Such a diversion was not made during 2009–10.

 

Quantification approach   


This line item comprises six different data-sets. The method for each data-set is shown below.

Note a: Delta Electricity

 

Data source

Level monitoring at the reservoirs, a radio telemetry system and data spreadsheets.

 

Data provider

The following storage reservoirs are managed by Delta Electricity:

  • Lake Lyell
  • Lake Wallace
  • Thomsons Creek Reservoir.

 

Method

  • Lake Lyell: manual level readings converted to a volume using a rating table in a spreadsheet.
  • Lake Wallace: telemetered level data from ultrasonic level sensors and radio telemetry system converted to a volume using a rating table in a spreadsheet.
  • Thomsons Creek Reservoir: telemetered level data from pressure sensors and radio telemetry system converted to a volume using a rating table in a spreadsheet.
 

 

Uncertainty

The volume is based on measured data. Uncertainty value based on meter accuracy is
+/–5%.

The NSW Office of Water conducts an annual verification review on Delta Electricity’s water data.

 

Approximations, assumptions, caveats/limitations

Nil.

 

Note b: Goulburn Mulwaree Council

 

Data source

Level monitoring at the reservoirs and data spreadsheets.

 

Data provider

The following storage reservoirs are managed by Goulburn Mulwaree Council:

  • Pejar Reservoir
  • Sooley Reservoir.
 

 

Method

Telemetered level data converted to a volume using a rating table in a spreadsheet. For Pejar Reservoir, manual level readings were used for some of the 2009–10 season, because level sensors were non-functional due to low water levels.

 

Uncertainty

The volume is based on measured data. Uncertainty value based on meter accuracy and professional judgment is +/–5%.

 

Approximations, assumptions, caveats/limitations

Nil.

 

Note c: Lithgow City Council

 

 

Data source

Level monitoring at Farmers Creek No. 2 Reservoir and data spreadsheets.

 

Data provider

Farmers Creek No. 2 Reservoir managed by Lithgow City Council.

Method

Manual level readings converted to a volume using a rating table in a spreadsheet.

 

Uncertainty

The volume is based on measured data. Uncertainty value is ungraded.

 

Approximations, assumptions, caveats/limitations

Information on dead storage volume is not available.

 

Note d: Shoalhaven City Council

 

Data source

Level monitoring at the reservoirs with hydrometric sensors linking to council’s radio telemetry system.

 

Data provider

Following storage reservoirs managed by Shoalhaven City Council:

  • Bamarang Reservoir
  • Danjera Reservoir
  • Flat Rock Creek Reservoir.
 

 

Method

Telemetered level data were converted to a volume using a rating table.

 

Uncertainty

The volume is based on measured data. Estimated uncertainty based on accuracy of level sensors and other level measuring devices, and rating tables is +/–5%.

 

Approximations, assumptions, caveats/limitations

Nil.

 

Note e: The Sydney Catchment Authority

 

Data source

Level monitoring at reservoirs—visual and hydrometric sensors, daily returns database and storage tables for reservoirs.

 

Data provider

The following storage reservoirs are managed by the Sydney Catchment Authority:

  • Cataract Reservoir
  • Cordeaux Reservoir
  • Avon Reservoir
  • Nepean Reservoir
  • Woronora Reservoir
  • Lake Burragorang (Warragamba Dam)
  • Prospect Reservoir
  • Wingecarribee Reservoir
  • Fitzroy Falls Reservoir
  • Lake Yarrunga (Tallowa Dam)
  • Blue Mountains reservoirs
    • Medlow Reservoir
    • Greaves Creek Reservoir
    • Upper Cascade Reservoir
    • Middle Cascade Reservoir
    • Lower Cascade Reservoir.

Method

Water level by visual inspection of gauging boards and from hydrometric sensors. Level readings converted to volume using rating tables. Storage tables for reservoirs are developed from bathymetric surveys and other methods.

 

Uncertainty

The volume is based on measured data. Estimated uncertainty based on accuracy of sensors and other level measuring devices, and professional judgment on rating tables is +/–5%.

 

Approximations, assumptions, caveats/limitations

Nil.

 

Note f: Wingecarribee Shire Council

 

Data source

Level monitoring at the reservoirs with Vega-type hydrometric sensors linking to council’s radio telemetry system and data spreadsheets.

 

Data provider

Following storage reservoirs managed by Wingecarribee Shire Council:

  • Bundanoon Reservoir
  • Medway Reservoir.

 

Method

Water levels received from level sensors located in the reservoirs through council’s radio telemetry system are converted to a volume using rating tables. In addition, water levels obtained by operation officers are loaded into a spreadsheet where rating tables produce storage volume.

 

Uncertainty

The volume is based on measured data. Estimated uncertainty based on sensor accuracy, organisational practice and professional judgment on rating tables is +/–10%. The data are externally audited.

 

Approximations, assumptions, caveats/limitations

Information on dead storage volume is not available.