Murray-Darling Basin
9.15 Increase of inter-region claim on water

Supporting Information

The line item applies only to the Southern Basin of the Murray–Darling Basin (MDB) region. The volumetric value for the line item for the 2010–11 year was 3,137,374 ML. The line item includes the required annual release (RAR) that Snowy Hydro was required to deliver to the Tumut River and River Murray (3,137,066 ML), and a claim by Grampians Wimmera–Mallee Water in the Glenelg Catchment (308 ML) for the 2010–11 year.

Claim for Snowy Hydro releases

The values shown in the following table was the RAR announced from 01 July 2010 to 30 June 2011 and related to the Snowy Water Year of 01 May 2011 to 30 April 2012. It also includes the dry inflow sequence volume (DISV) adjustments made to the RAR during the year on a month-by-month basis. 


Required annual release for the 2010–11 year and Snowy Water Year 2011–12

Tumut River (ML)

River Murray (ML)

Total (ML)

Fixed annual calculated yield for development




Minus Snowy Water allocation




Plus Change in DISV reduction over year




Equals RAR for Snowy Hydro Water Year 2011–12





Line item 1.5 Inter-region claim on water explains in more detail the arrangements for the calculation of the RAR.

Claim by Grampians Wimmera Mallee Water on water in the Glenelg River

Under a Victorian bulk entitlement, Grampians Wimmera–Mallee Water is able to transfer water from the Glenelg River upstream of and including Rocklands Reservoir; and the First and Second Wannon creeks upstream of and including the weirs to the Wimmera–Mallee supply system, located within the MDB region's boundaries.

The total of the water transferred-in during the 2010–11 year was 308 ML reported under line item 9.11 Delivery of water under inter-region agreement.


Quantification Approach

Data Source

(1) Snowy Hydro transfers: Snowy Hydro Limited Water Operations Report 2010–11, (2) Snowy deals with New South Wales irrigators: New South Wales Office of Water's Water Accounting section, and (3) water audit monitoring (WAM) data received from Victoria (31 January 2012) and stored in the Murray–Darling Basin Authority HYDRO database.

Provided by

Murray–Darling Basin Authority.


Snowy Hydro required annual release at the beginning of the Snowy Water Year (01 May) was based on the calculations in the Snowy Water Licence.

Quantification method was not available for the WAM data received for this line item.

Assumptions, Limitations, Caveats and Approximations

Snowy Hydro Claim: Numbers were estimated at the commencement of the water year, and subject to revision and confirmation at the end of the year.

Inflows to Hume reservoir for the River Murray are subject to a formula for calculating the respective New South Wales and Victorian shares, which is 50% between New South Wales and Victoria with some adjustments.

Uncertainty Information

The uncertainty estimate was not quantified.

Comparative year

The value reported as comparative year corresponds to the 23.1 Interbasin claim over water in other regions registered that were reported in the 2010 Account.