17.17 Decrease of inter-region claim on water

Supporting Information

The volume presented in the water accounting statements (10,084 ML) represents the decrease to the claim that Melbourne retail authorities City West Water, South East Water and Yarra Valley Water are 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 decreases to inter-region claims for the Melbourne Region during 2010–11.

Decrease of inter-region claims
Component Volume (ML)
Evaporation from share of Thomson Reservoir 9,536
Decrease of claim on Silver and Wallaby Creeks 0
Evaporation from share of Lake Eildon 548
Total 10,084

Quantification Approach

Data Source

Melbourne Water: Waterworks database.

Provided by

Melbourne Water.


Decreases to inter-region claims held by the Melbourne region were calculated using the following methods: 

Thomson Reservoir
Evaporation of the water share of Melbourne retailers in Thomson Reservoir is determined using the Pan Evaporation method.
Silver and Wallaby Creeks

There were no decreases to the inter-region claim on water from Silver and Wallaby Creeks during the 2010–11 year.

Lake Eildon

Five percent of the water held in Lake Eildon for the Melbourne region is subtracted on 01 July each year to account for annual evaporation, as per the Carryover for water shares in the Murray, Goulburn and Campaspe water systems 2010.

Assumptions, Limitations, Caveats and Approximations


Uncertainty Information

The uncertainty estimate was not quantified.

Comparative year

There was no corresponding line item reported in the 2010 Account. The comparative year volume is 0 ML.