Murray–Darling Basin
1.5 Inter-region claim on water

Supporting information

The volumetric value for the line item at the end of the 2011–12 year was 913,776 ML. This line item includes claims on Snowy Hydro Limited (Snowy Hydro) for the balance of the required annual release (RAR). The line item applies only to the Southern Basin.


Volumes claim against Snowy Hydro
Description

Tumut River (ML)

Murray River (ML)

Total

As at 30 June 2012

As at 30 June 2011

As at 30 June 2012

As at 30 June 2011

As at 30 June 2012

As at 30 June 2011
Fixed annual calculated yield for the development

1,026,000

1,026,000

1,062,000

1,062,000

2,088,000

2,088,000
Less releases made during previous Snowy water year1, in excess the previous year's RAR2 adjusted by DISV3 at 1 March

55,000

0

293,000

222,000

348,000

222,000
Less water allocation from prior Snowy water year for environmental releases

127,352

120,788

96,872

101,146

224,224

221,934
Plus other RAR adjustment4

39,000

0

39,000

0

78,000

0
RAR at the commencement of the Snowy water year (1 May)

882,648

905,212

711,128

738,854

1,593,776

1,644,066
Less accountable release to 30 June5

145,000

69,000

228,000

273,000

373,000

342,000
Less DISV increase6 at 30 June

0

325,000

307,000

507,000

307,000

832,000
RAR remaining at 30 June

737,648

511,212

176,128

-41,146

913,776

470,066
  1. The Snowy water year: Snowy Hydro water year, which is from 1 May to 30 April.
  2. RAR = required annual release.
  3. DISV = dry inflow sequence volume.
  4. Reduction of 78,000 ML under Clause 13.2 of the Snowy water licence in 2011–12 Snowy water year from the Tumut River has been nominated for release the same volume during 2012–13 Snowy water year. At this stage the release is nominated from each of the Murray River and the Tumut River equally.
  5. The accountable release volume at 30 June 2012 is a preliminary estimate only and subject to confirmation and revision.
  6. DISV increase = dry inflow sequence volume increase relative to 1 March in the previous water year.

Claim for Snowy Hydro releases remaining

Each Snowy water year, Snowy Hydro must release the RAR to the Tumut River and the Murray River. The RAR is set at the commencement of the Snowy water year for delivery over the next 12 months.

In drier times, DISV allowance is made for reduced inflows to the Snowy Mountains Scheme. In the original Snowy water licence, the DISV reduced the RAR when inflows were lower than the historical drought sequence volumes, and increased the RAR as inflows recovered; however in the Snowy water licence amendments that took effect on 4 October 2011, the RAR formula (refer to the table above) was modified to deduct (non-negative) DISV increase rather than add DISV from the previous 1 March and subtract the current DISV. This change resulted in the same reduced RAR during continuing dry conditions but when inflows improve (when recovering from a DISV state), the DISV recovery volumes are now stored in drought accounts rather than increasing the RAR.  DISV Increase adjustments are made to RAR on a monthly basis through the Snowy water year up to 1 March.

Environmental water savings transferred from the Murrumbidgee River and the Murray River to the Snowy River or the montane streams result from entitlements acquired in the Murray–Darling Basin (MDB) through completion of water saving infrastructure projects or purchases of entitlements. When allocations are announced against these entitlements, the RAR (claim against Snowy Hydro) is reduced. Snowy Hydro subsequently makes these environmental releases to the Snowy River and other montane streams.

Snowy deals with New South Wales irrigators

Included within this line item are the Snowy Hydro deals with New South Wales irrigators. This refers to a dealing whereby water access licence holders in the Murrumbidgee and New South Wales Murray negotiated with Snowy Hydro to release water to Blowering Reservoir and Hume Reservoir earlier-than-required to provide the water under their RAR. This is not considered a trade, as Snowy Hydro Limited does not own the water; rather, it is just an earlier than required transfer. The licence holder is required to pay Snowy Hydro back at a point in the future through a reduction in licence holder's allocation water.

The volume is not included in the water accounting statement for this line item as the MDB region does not have a claim on Snowy Hydro or the water access licence holders, but it is disclosed as it will have an impact on the value of the RAR.

Payback if any to Snowy Hydro is shown in line item 13.1 'Adjustment and forfeiture of surface water allocation'. During the 2011–12 year, there was no borrowing or payback related to agreements between Snowy Hydro and New South Wales licence holders.

 

Snowy Hydro deals with New South Wales irrigators
Description

The 2011–12 year

The 2010–11 year

Tumut River (ML)

Murray River(ML)

Tumut River (ML)

Murray River (ML)

Balance owing to Snowy Hydro at 01 July  0 0 152,519 205,205
Borrowed from Snowy Hydro 0 0 0 0
Payback to Snowy Hydro 0 0 152,519 205,205
Balance owing to Snowy Hydro at 30 June  0 0 0 0

Note : The values in this table may vary from those stated in information provided by Snowy Hydro due to variations in reporting years.

Quantification approach

Data source

Snowy Hydro Limited: Snowy Hydro Required Annual Release, from Water Operations Report and NSW Office of Water's Water Accounting section: Snowy deals with New South Wales irrigators.

Provided by

NSW Office of Water and Snowy Hydro Limited.

Method

Snowy Hydro RAR:

  • Snowy Hydro RAR at the commencement of the Snowy Water Year (1 May) is based on the calculations in the Snowy Water Licence.
  • Snowy Hydro RAR remaining at 30 June adjusts the RAR at 1 May by the estimated progressive releases (in ML) from 1 May to 30 June.

Inputs to the calculation of the RAR include:

  • 1,062 GL for the Murray River and 1,026 GL for the Tumut River­—the precorporatisation RAR
  • the dry inflow sequence volume
  • environmental water savings transferred from the Murrumbidgee River and the Murray River to the Snowy River or the montane streams
  • recognition of when Snowy Hydro has made a water release in advance of the Snowy water year
  • transfers between the Tumut River and the Murray River
  • recognition of water deals between Snowy Hydro and downstream irrigators (both the borrowings and the subsequent paybacks).
  • any other RAR adjustment.

Snowy deals with New South Wales irrigators are as recorded by the New South Wales Office of Water.

Assumptions, limitations, caveats and approximations

Nil.

Uncertainty information

Snowy Hydro required annual release

The uncertainty estimate was not quantified. Numbers are estimated at the commencement of the water year and subject to revision and confirmation at the end of the year.

Snowy deals with New South Wales irrigators

The uncertainty estimate was not quantified.