Murray–Darling Basin

7.1 Interbasin claim on water – remaining

Supporting information

The volumetric value for the line item at the end of 2009–10 is 409,000 ML (see the following table). This line item includes claims on Snowy Hydro for the balance of the required annual release (RAR) for 2009–10.

Volume claims against Snowy Hydro at 30 June 2010
	End of 2009	End of 2010	End of 2009	End of 2010	End of 2009	End of 2010
	Tumut River (ML)		River Murray (ML)		Total
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
Plus DISV as at 01 March from previous Snowy Water Year	429,000	481,000	679,000	784,000	1,108,000	1,265,000
Less releases made during previous Snowy Water Year, in excess the previous year’s RAR adjusted by DISV at 01 March	138,000	12,000	72,000	16,000	210,000	28,000
Less water allocation from prior Snowy Water Year for environmental releases	45,000	71,000	18,000	22,000	63,000	93,000
RAR at the commencement of the Snowy water year (01 May)	1,272,000	1,424,000	1,651,000	1,808,000	2,923,000	3,232,000
Less accountable release to 30 June	51,000	156,000¹	198,000	265,000¹	249,000	421,000
Less DISV reduction at 30 June	1,155,000	1,110,000	1,318,000	1,292,000	2,473,000	2,402,000
Less repayment of Murrumbidgee Water Deal 2006/07 planned at 30 June	3,000	0	0	0	3,000	0
RAR remaining at 30 June	63,000	158,000	135,000	251,000	198,000	409,000

DISV = Dry Inflow Sequence Volume

1 The value of the accountable release at 30 June 2010 (end of 2010) is a preliminary estimate only and subject to confirmation and revision.

Claim for Snowy Hydro releases remaining

The Snowy Hydro water year is from 01 May to 30 April (the Snowy Water Year). Each Snowy Water Year, Snowy Hydro Ltd (Snowy Hydro) must release the RAR to the Tumut River and River Murray. The RAR is set at the commencement of the Snowy Water Year for delivery over the next 12 months.

In drier times, an allowance, the Dry Inflow Sequence Volume (DISV), is made for reduced inflows to the Snowy Mountains Scheme. The DISV reduces the RAR when inflows are low and increases the RAR when inflows recover. These DISV adjustments are made on a monthly basis through the Snowy Water Year up to 01 March.

Environmental water savings transferred from the Murrumbidgee River and River Murray 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 Deals with New South Wales irrigators

Included within this 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 payback Snowy Hydro at a point in the future through a reduction in their 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 impact on the value of the RAR.

The payback to Snowy Hydro is shown in Line item 26.1.3.6 Adjustment and forfeiture of allocation on regulated flows – general and low-security, other lumped holders. During 2009–10, 17,449 ML was repaid by the licence holders to Snowy Hydro.

Snowy Hydro deals with New South Wales irrigators, 2009–10
	Tumut River (ML)	River Murray (ML)
Balance owing to Snowy Hydro at 01 July 2009	169,968	205,205
Borrow from Snowy Hydro	0	0
Payback to Snowy Hydro	17,449	0
Balance owing to Snowy Hydro at 30 June 2010	152,519	205,205

Note: The figures in this table may vary from those stated in information provided by Snowy Hydro due to variations in reporting period. For instance, payback to Snowy Hydro during the 2009–10 Snowy Hydro Year (01 May to 31 April) was 3,000 ML, while it was 17,449 ML during the 2009–10 National Water Account 2010 reporting period (01 July to 30 June).

Quantification approach

Data source

Snowy Hydro Required Annual Release: Snowy Hydro Ltd Water Operations Report 2009–10.

Snowy Deals with NSW Irrigators: NSW Office of Water’s Water Accounting section.

Data provider

Murray–Darling Basin Authority (MDBA).

Method

Snowy Hydro RAR:

Snowy Hydro RAR at the commencement of the Snowy Water Year (01 May) is based on the calculations in the Snowy Water Licence.
Snowy Hydro RAR remaining at 30 June adjusts the RAR at 01 May by the estimated progressive releases (in ML) from 01 May to 30 June.
Inputs to the calculation of the RAR include:
- 1,062 GL for the River Murray and 1,026 GL for the Tumut River – the precorporatisation RAR
- the Dry Inflow Sequence Volume (DISV)
- environmental water savings being transferred from the Murrumbidgee River and River Murray to the Snowy River or the montane streams
- recognising when Snowy Hydro has made a water release in advance of the Snowy Water Year
- transfers between the Tumut River and the River Murray
- recognising water deals between Snowy Hydro and downstream irrigators (both the borrowings and the subsequent paybacks).

Snowy Deals with New South Wales irrigators: as recorded by the NSW Office of Water.

Uncertainty

Snowy Hydro Required Annual Release

Uncertainty is ungraded. 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 NSW Irrigators

Uncertainty is ungraded.

Approximations, assumptions, caveats/limitations

Nil.