Melbourne
1.5 Inter-region claim on water

Supporting Information

The volume presented in the water accounting statements (456,522 ML) represents the total volume of water that Melbourne retail authorities City West Water, South East Water and Yarra Valley Water were entitled to under:

  • bulk entitlements for Thomson Reservoir, and Silver and Wallaby creeks
  • agreement for water held in Lake Eildon.

The following table presents the breakdown of inter-region claim remaining in the Melbourne region at the start and end of the 2010–11 year.


Inter-region claim in the Melbourne region
Source 30 June 2010 (ML)
30 June 2011 (ML)
Thomson Reservoir 213,600 406,100
Silver and Wallaby creeks 0
0
Lake Eildon 10,965 50,422
Total 224,565 456,522

Thomson Reservoir

Melbourne retail authorities have claim to water in the Thomson Reservoir under the following bulk entitlements:

  • Thomson River – City West Water
  • Thomson River – South East Water
  • Thomson River – Yarra Valley Water

Bulk entitlements allow Melbourne retail authorities to hold a share of the Thomson Reservoir up to its capacity (1,068,100 ML). Storage volume is shared by Melbourne's retail authorities with other users in adjacent regions, who hold the following bulk entitlements:

  • Thomson River – Environment
  • Thomson Macalister – Southern Rural Water

Bulk entitlements allow the environment and Southern Rural Water to hold a share of the Thomson Reservoir up to 10,000 ML and 45,000 ML, respectively. 

The calculation of the inter-region claim remaining on water stored in Thomson Reservoir is presented in the following table.

Inter-region claim on Thomson Reservoir

Account Volume (ML)

Opening balance (30 June 2010) 213,600
add 9.15 Increase of inter-region claim on water 203,636
less 9.11 Delivery of water under inter-region agreement  1,600
less 17.17 Decrease of inter-region claim on water 9,536

Closing balance (30 June 2011) 406,100

Water stored in Thomson Reservoir is delivered to Upper Yarra Reservoir for distribution to Melbourne's water supply system. The total volume of water delivered to the Melbourne Region from Thomson Reservoir is presented as part of 9.11 Delivery of water under inter-region agreement.

Silver and Wallaby Creeks

Melbourne retail authorities have claim to water from Silver and Wallaby creeks under the following bulk entitlements:

  • Silver and Wallaby creeks - City West Water
  • Silver and Wallaby creeks - South East Water
  • Silver and Wallaby creeks - Yarra Valley Water

The Bulk Entitlement specifies that a maximum volume of 66,000 ML may be diverted from Silver and Wallaby creeks over a three-year period (subject to rules specified in the bulk entitlements). If less than the maximum volume is diverted, the remaining volume is not carried over to the following year. Subsequently the opening and closing balance of the claim remains zero.

Water is diverted from Silver and Wallaby creeks, and delivered to Tooroorung Reservoir and Yan Yean Reservoir for distribution to Melbourne's water supply system. The total volume of water delivered from Silver and Wallaby creeks is presented as part of 9.11 Delivery of water under inter-region agreement.

Lake Eildon

Melbourne retail authorities have claim to water from Lake Eildon under the following agreements:

  • Water savings supply and transfer agreement (an unpublished document).

Under the agreement, water savings from Stage 1 of the Northern Victoria Irrigation Renewal Project were allocated to Melbourne retail authorities and stored in Lake Eildon. In 2010–11, as a once-off arrangement, some unallocated water savings achieved from the CG1234 Modernisation Project and Shepparton Modernisation Project were also allocated to Melbourne.

The calculation of the inter-region claim remaining on water stored in Lake Eildon is presented in the following table.

Inter-region claim on Lake Eildon

Account Volume (ML)

Opening balance (30 June 2010) 10,965
add

9.15 Increase of inter-region claim on water

47,481
less

9.11 Delivery of water under inter-region agreement

7,476
less

17.17 Decrease of inter-region claim on water

548

Closing balance (30 June 2011) 50,422


Water stored in Lake Eildon is delivered to Sugarloaf Reservoir via the North–South Pipeline for distribution to Melbourne's water supply system. The total volume of water delivered to the Melbourne region from Lake Eildon is presented as part of 9.11 Delivery of water under inter-region agreement

Further information on bulk entitlements can be found at the Victorian Water Register.

Comparative year

This item corresponds to line item 7.1 Inter-basin claim on water– remaining reported in the 2010 Account. A typographical error in the volume reported in the 2010 Account was identified, which caused the 2009–10 year volume to be restated.

This change and the respective volumes are detailed in the following table. The restated comparative year volume is 224,565 ML.

Restated comparative year information for line item 1.5 Inter-region claim on water

2010 Account line item name

Volume at 30 June 2010 reported in the 2010 Account (ML)

Value difference to volume reported due to prior period error correction (ML)

Volume at 30 June 2010 reported in 2011 Account (ML)

7.1 Inter-basin claim on water– remaining

224,566

-1

224,565