Murray-Darling Basin
5.1 Surface water allocation remaining

Supporting Information
Quantification Approach
Comparative year

Supporting Information

The volumetric value for the line item for the 2010–11 year was 6,510,038 ML. The line item represents surface water allocation remaining (excluding urban water systems) associated with a number of entitlement classes in the Murray–Darling Basin (MDB) region as at 30 June 2011. Information on surface water allocation remaining for urban water systems is included in line item 5.2 Surface water allocation remaining – urban water system.

The line item value was derived by deducting overdraft of surface water allocation (323 ML) from allocation carry-over volume (6,510,361 ML) at end of the 2010–11 year. Details of allocation carry-over and overdraft of surface water allocation volumes are provided in the following tables.

Water allocation carry-over

The following two tables provide a summary and breakdown information on surface water allocation carry-over (excluding urban water systems) within the region.

Summary of surface water allocation carry-over (excluding urban water systems) in the MDB region
Surface water resource plan area		State	Volume (ML) as at 30 June 2011
Code	Name	State	Volume (ML) as at 30 June 2011
SW19	Warrego – Paroo – Nebine	Qld	–
SW18	Condamine–Balonne	Qld	14,667
SW17	Moonie	Qld	na
SW16	Qld Border Rivers	Qld	–
SW15	NSW Border Rivers	NSW	209,506
SW11	Barwon–Darling watercourse	NSW	na
SW12	NSW Intersecting Streams	NSW	na
SW14	Gwydir	NSW	342,552
SW13	Namoi	NSW	255,050
SW10	Macquarie–Castlereagh	NSW	519,842
*Sub-total Northern Basin*			*1,341,617*
SW9	Lachlan	NSW	669,258
SW8	Murrumbidgee NSW	NSW	600,178
SW7	NSW Murray and Lower Darling	NSW	1,284,159
SW3	Northern Victoria	Vic	1,138,910
SW2	Vic Murray	Vic	1,385,377
SW4	Wimmera–Mallee	Vic	90,862
SW6	Eastern Mount Lofty Ranges	SA	–
SW5	SA Murray	SA	–
SW1	ACT	ACT	na
Sub-total Southern Basin			5,168,744
Total for the region			6,510,361

– = Data not available, na = not applicable

Details of surface water allocation carry-over (excluding urban water systems) in the MDB region
Water resource plan area	Sustainable diversion limit area		State	Entitlement class	Volume (ML) as at 30 June 2011
Water resource plan area	Code	Name	State	Entitlement class	Volume (ML) as at 30 June 2011
Warrego–Paroo–Nebine	SS28	Warrego	Qld	Supplemented	0
Condamine–Balonne	SS26	Condamine–Balonne	Qld	Supplemented	14,667
Qld Border Rivers	SS24	Qld Border Rivers	Qld	Supplemented	0
*Sub-total Queensland*					*14,667*
NSW Border Rivers	SS23	NSW Border Rivers	NSW	High security	0
				General security	209,506
				Stock and domestic	0
				*Sub-total*	*209,506*
Gwydir	SS22	Gwydir	NSW	High security	0
				General security	342,552
				Stock and domestic	0
				High security – research	0
				*Sub-total*	*342,552*
Namoi	SS21	Namoi	NSW	High security	0
				General security	255,050
				Stock and domestic	0
				High security – research	0
				*Sub-total*	*255,050*
Macquarie–Castlereagh	SS20	Macquarie–Castlereagh	NSW	High security	0
				General security	519,842
				Stock and domestic	0
				High security – research	0
				*Sub-total*	*519,842*
Lachlan	SS16	Lachlan	NSW	High security	0
				General security	669,258
				Stock and domestic	0
				Conveyance	0
				*Sub-total*	*669,258*
Murrumbidgee NSW	SS15	Murrumbidgee NSW	NSW	General security	506,959
				Stock and domestic	0
				Conveyance	93,219
				*Sub-total*	*600,178*
NSW Murray and Lower Darling	SS18	Lower Darling	NSW	High security	3,502
				General security	54,399
				Supplementary	0
				Stock and domestic	0
				*Sub-total*	*57,901*
	SS14	NSW Murray	NSW	High security	86,148
				General security	1,139,234
				Supplementary	0
				Stock and domestic	0
				Conveyance	41
				High security – research	800
				High security – Aboriginal cultural	0
				High Security – community & education	35
				*Sub-total*	*1,226,258*
*Sub-total New South Wales*					*3,880,545*
Northern Victoria	SS4	Ovens	Vic	High reliability water share	0
	SS5	Broken	Vic	Combined high and low reliability	10,075
	SS6	Goulburn	Vic	Combined high and low reliability	1,072,295
	SS7	Campaspe	Vic	Combined high and low reliability	41,586
	SS8	Loddon	Vic	Combined high and low reliability	14,954
Vic Murray	SS2	Vic Murray	Vic	Combined high and low reliability	1,385,377
Wimmera–Mallee	SS9	Wimmera–Mallee	Vic	High reliability water share	90,862
*Sub-total Victoria*					*2,615,149*
Eastern Mount Lofty Ranges	SS13	Eastern Mount Lofty Ranges	SA	Regulated	–
				unregulated	–
				*Sub-total*	–
SA Murray	SS11	SA Murray	SA	Class 1 – Stock and domestic	0
				Class 2 – Other urban (country town) water supply	na
				Class 3 – Irrigation and holding	0
				Class 4 – Recreation	0
				Class 5 – Industrial	0
				Class 6 – Metro-Adelaide water supply scheme	na
				Class 7 – Environment	–
				Class 8 – Environmental land management	–
				Combined classes urban	na
				Combined classes metered	0
				Combined classes unmetered	0
				*Sub-total*	0
	SS10	SA Non-prescribed areas	SA	Regulated	–
				unregulated	–
				*Sub-total*	–
Eastern Mount Lofty Ranges	SS12	Marne-Saunders	SA	Regulated	–
				unregulated	–
				Sub-total	–
Sub-total South Australia					0
Total for the region					6,510,361

– = Data not available, na = not applicable

Queensland

In Queensland, the resource operation plans (ROPs) distinguish between high and medium priorities of supplemented water allocation. The Water Audit Monitoring (WAM) data that are the data source for the 2011 Account only distinguish between supplemented and unsupplemented entitlements. Both urban and non-urban entitlements are included within supplemented entitlement class. Supplemented urban and supplemented non-urban volumes on allocations, diversions and other attributes were received together and it was not possible to separate out these two types of entitlements. Therefore, this line item includes remaining allocation volumes for both urban (if any, normally forfeited) and non-urban supplemented entitlements.

NSW

Allocations remaining for several stock and domestic entitlements in New South Wales sustainable diversion limit (SDL) areas were negative volumes. This could be due to:

overdraft of surface water allocation (advance drawing)
overuse breach of licence condition
an accounting/licensing anomaly arising as the entitlement holder holds many licences but the accounting was on one licence only (the anomaly continues until consolidating licences and fixing in the database occurs).

While some New South Wales water sharing plans remained suspended for the 2010–11 year, there has been provision to carry-over high-security class allocation remaining water in the Lower Darling, Murrumbidgee and Murray SDL areas.

Victoria

All the allocation remaining as at 30 June 2011 was eligible for carry-over. In the Goulburn, Murray and Campaspe systems, if the total volume of carry-over is greater than the sum of the high- and low-reliability water shares, then this excess is placed in a spillable water account (SWA). From the start of the 2011–12 year, the SWA water only becomes available when the resource manager declares that there is a low risk of spilling. All other carry-over is available for use immediately.

In Victoria, once an allocation is made to an allocation account it no longer has the characteristic of being either high or low reliability. Therefore, all allocation remaining volumes were reported as combined high and low reliability water share.

South Australia

No carry-over was permitted for South Australian Murray at the end of the 2010–11 year.

Overdraft of surface water allocation

The following table provides details of overdraft of surface water allocation (excluding urban water systems) within the region.

Details of overdraft of surface water allocation in the MDB region during 2010–11
Water resource plan area	SDL area		State	Entitlement Class	Volume (ML) as at 30 June 2011
	Code	Name
Macquarie–Castlereagh	SS20	Macquarie-–Castlereagh	NSW	High security	33
				Stock and domestic	273
				*Sub-total*	*306*
Murrumbidgee NSW	SS15	Murrumbidgee NSW	NSW	High security	16
NSW Murray	SS14	NSW Murray	NSW	Stock and domestic	1
Total for the region					323

Advance diversion may occur where the water sharing plans or rules provide for water to be used in advance of the allocation. In New South Wales, this is repaid in the following year when the allocation announcement is made. New South Wales data include volumes that have been overdrawn for stock and domestic and high-security entitlements.

Quantification Approach

Data Source

(1) New South Wales: NSW Office of Water's Water Accounting section, (2) Queensland: Water Audit Monitoring data received on 22 December 2011 and stored in the Murray–Darling Basin Authority HYDRO database, and (3) Victoria: Department of Sustainability and Environment's Water Entitlements and Trade section. Water Audit Monitoring Report refers to the 2010-11 workbooks prepared by the states in order for the Murray–Darling Basin Authority to produce the published Water Audit Monitoring Report 2010-11, and Water Audit Monitoring data are stored in the Murray–Darling Basin Authority HYDRO database.

Provided by

Murray–Darling Basin Authority.

Method

Water sharing plans, water resource plans and the water legislation of each state specify the classes of licences that are permitted to carry forward any unused volumes and rules attached to the volume that may be carried forward.

Allocation remaining (carry-over) volumes and allocation diversion (overdraw) of surface water allocation remaining were as calculated by the States.

Assumptions, Limitations, Caveats and Approximations

Uncertainty reported by New South Wales Office of Water accounts for possible errors in quantification of diversions and data handling processes.

Only New South Wales and Queensland carry-over data is shown by a specific security class. This reflects the carry-over rules in the water resource plans.

Information provided in this line item may have been based on Cap valleys in the HYDRO database which may not align perfectly with SDL areas.

Uncertainty Information

The uncertainty value for the New South Wales data provided in this line item is +/– 10%. The uncertainty value for the Victoria data provided in this line item is +/– 1%. For the other data provided in this line item, the uncertainty estimate was not quantified.

Comparative year

This line item corresponds to line items listed in the following table and reported in the 2010 Account. In the 2011 Account, the following changes were made that caused the 2009–10 year value to be restated:

Presentation and classification of the line items has changed since the 2010 Account.
An error correction was made to the values reported in the 2010 Account.

The changes and their respective values are detailed in the following table.

Restatement of comparative year information made for the line item 5.1 Surface water allocation remaining
Description		Northern Basin (ML)	Southern Basin (ML)	Whole region (ML)
Line item names and values reported as at 30 June 2010 in the 2010 Account	7.6 Non-physical surface water asset – other lumped	361	55	416
	8.1.1.1 Allocation on regulated flows remaining – Stock and domestic water access entitlement	0	0	0
	8.1.2.5 Allocation on regulated flows remaining – high-security, individual holder for stock and domestic	0	0	0
	8.1.2.7 Allocation on regulated flows remaining – high-security, other lumped holders	0	20,169	20,169
	8.1.3.6 Allocation on regulated flows remaining – general and low-security, other lumped holders	118,631	1,016,650	1,135,281
	8.1.9.1 Allocation on regulated flows remaining – bulk irrigator holder	0	96,307	96,307
	8.1.9.2 Allocation on regulated flows remaining – individual irrigator holder	0	0	0
	8.1.9.7 Allocation on regulated flows remaining – Other lumped holders	0	1,119,261	1,119,261
	*Total value reported for the 2010 Account (total for line items 8.1.1.1 to 8.1.9.7 minus the value for line item 7.6)*	*118,270*	*2,252,332*	*2,370,602*
Changes in the value reported in the 2010 Account due to regrouping of line items		14,442	–2,928	11,514
Prior period error correction to the value reported in the 2010 Account values		0	2	2
Value reported for 30 June 2010 in the 2011 Account		132,712	2,249,406	2,382,118

Changes in the value reported in the 2010 Account due to regrouping of line items were due to the following reasons:

In the 2010 Account Queensland carry-over volumes were included in the allocation announcement. In the 2011 Account the Queensland carry-over volumes were separated from allocation announcement and are shown in this line item for both the opening and closing balances.
The high security entitlement classes within New South Wales for research, industrial, cultural, community and education were reported under urban line items in the 2010 Account. Remaining allocations associated with these entitlement classes were designated as non-urban and included in this line item for the 2011 Account.
In the 2010 Account, Victorian allocation remaining volumes were not separated into urban and non-urban and reported under line item 8.1.9.7 Allocation diversion of regulated flows – other lumped holders. For the 2011 Account, these volumes were restated after separating into urban and non-urban entitlement classes.

Prior period error correction was due to 2 ML change made to overdraft of surface water allocation volume on 30 June 2010 reported for the 2010 Account.

Murray-Darling Basin5.1 Surface water allocation remaining