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General Purpose Water Accounting Report 2009–2010

Namoi Catchment

Publisher

NSW Office of Water

Level 17, 227 Elizabeth Street GPO Box 3889 Sydney NSW 2001

T 02 8281 7777 F 02 8281 7799

[email protected]

www.water.nsw.gov.au

The NSW Office of Water is a separate office within the Department of Environment, Climate Change and Water. The Office of Water manages the policy and regulatory frameworks for the State’s surface water and groundwater resources to provide a secure and sustainable water supply for all users. The Office of Water also supports water utilities in the provision of water and sewerage services throughout New South Wales.

General Purpose Water Accounting Report 2009–2010: Namoi CatchmentMarch 2011

ISBN 978 1 74263 178 3

A description of the Namoi catchment, Water resources and management overview: Namoi Catchment has been published in conjunction with this report.

Acknowledgment

Soil data for groundwater methodologies provided by the Natural Resources Data Programs (soils) unit of the NSW Department of Environment, Climate Change and Water.

This report may be cited as:

Burrell M., Moss P., Green D., Ali A., Petrovic J. (2011) General Purpose Water Accounting Report 2009–2010: Namoi Catchment, NSW Office of Water, Sydney

Cover photo: Namoi River at Walgett (courtesy of Dayle Green)

© State of New South Wales through the Department of Environment, Climate Change and Water, 2011

This material may be reproduced in whole or in part for educational and non-commercial use, providing the meaning is unchanged and its source, publisher and authorship are clearly and correctly acknowledged.

Disclaimer: While every reasonable effort has been made to ensure that this document is correct at the time of publication, the State of New South Wales, its agents and employees, disclaim any and all liability to any person in respect of anything or the consequences of anything done or omitted to be done in reliance upon the whole or any part of this document.

Maps: The maps are to be used as a general guide for regional and local scale natural resource planning and management only, not for the assessment of specific sites which can only be assessed by investigation specific to those sites.

The maps are published by the NSW Office of Water. While every reasonable effort has been made to ensure the accuracy of the information contained in the maps, you should only satisfy yourself as to the accuracy of the information before relying on it.

NOW 10_375

General Purpose Water Accounting Report 2009 –2010: Namoi Catchment

Background The National Water Initiative (NWI) is Australia's enduring blueprint for water reform. Through this

initiative, governments across Australia have agreed on actions to achieve a more cohesive national approach to the way Australia manages, measures, plans for, prices, and trades water.

Following the intergovernmental agreement on the NWI, the Water Accounting Standards Board

(WASB) was formed to create a national standard for water accounting. WASB operates as independent advisory board to the Bureau of Meteorology (BoM) which has produced the ‘Exposure Draft of Australian Water Accounting Standard 1 (ED AWAS 1)’. This draft standard defines the

structure for preparing a ‘General Purpose Water Accounting Report’ (GPWAR)’ and, following a consultation and review phase, will transition to the Australian Water Accounting Standard (AWAS)

This GPWAR is a water account for regulated river component of the Namoi catchment (including the

Peel Valley), and the groundwater aquifers of the Namoi catchment. It has been prepared by the NSW Office of Water, under the ED AWAS 1 framework for the 2009-10 water year. This GPWAR aims to provide a consolidated and informative summary of the water resources available and the water

management that occurred within the valley for the reporting period.

A GPWAR prepared in accordance with the ED AWAS 1 will contain:

• A contextual statement – detailing the climate and water management in place for the

reporting period (2009-10).

• A statement of water assets and water liabilities for 2009-10.

• A statement of changes in water assets and water liabilities for 2009-10.

• A statement of physical water flows for 2009-10.

• Note disclosures – a section of notes referenced to line items within the above statements that explain in detail the source of the data, how the number was derived and

the expected uncertainty associated with the number. This section also contains reconciliation statements required by the ED AWAS 1.

• An assurance statement.

• An accountability statement.

i | NSW Office of Water, March 2011

General Purpose Water Accounting Report 2009-2010 – Namoi Catchment

Table of Contents

Background............................................................................................................................................i

Contextual Statement.......................................................................................................................... 1 1.1 Introduction ............................................................................................................................ 2 1.2 Namoi catchment ................................................................................................................... 2 1.3 Geographic boundaries of the Namoi water reporting entity ................................................. 3 Surface water ......................................................................................................................... 3 Groundwater .......................................................................................................................... 4

1.4 Climate ................................................................................................................................... 5 1.5 Policy.................................................................................................................................... 12 1.6 Management ........................................................................................................................ 12

Surface water ....................................................................................................................... 12 Groundwater ........................................................................................................................ 18

1.7 Environmental water ............................................................................................................ 19 Held environmental water .................................................................................................... 19 Planned environmental water .............................................................................................. 19

Water Accounting Statements ......................................................................................................... 20 Water Accounting Statement Descriptions..................................................................................... 21 Other statement descriptions ......................................................................................................... 25 Accountability Statement................................................................................................................ 26

Note disclosures................................................................................................................................ 37 Reconciliation and future prospect descriptions............................................................................. 38 Note 1 – Surface water storage...................................................................................................... 42 Note 2 – River channel storage...................................................................................................... 43 Note 3 – Groundwater storage....................................................................................................... 44 Note 4 – Allocation accounts.......................................................................................................... 49 Note 5 – Storage inflow .................................................................................................................. 53 Note 6 – Gauged inflow.................................................................................................................. 54 Note 7 – Ungauged inflow.............................................................................................................. 55 Note 8 – Ground water balance methodologies............................................................................. 56 Note 9 – Internal trading................................................................................................................. 62 Note 10 – Storage evaporation and storage rainfall ...................................................................... 64 Note 11 – River evaporation and river rainfall................................................................................ 66 Note 12 – End of system flow......................................................................................................... 67 Note 13 – Uncontrolled flow/off-allocation...................................................................................... 70 Note 14 – Supplementary extraction.............................................................................................. 71 Note 15 – Basic rights .................................................................................................................... 72 Note 16 – Available Water Determination (AWD) (Allocation Announcement).............................. 73 Note 17 – Unaccounted-for difference ........................................................................................... 78 Note 18 – Extractions ..................................................................................................................... 79 Note 19 – Held environmental water.............................................................................................. 81 Note 20 – Water order debiting ...................................................................................................... 84 Note 21 – Dungowan pipeline diversion......................................................................................... 85 Assurance Statement ..................................................................................................................... 86

References ......................................................................................................................................... 87

ii | NSW Office of Water, March 2011


Tables Table 1: Upper Namoi opening announcements for 2009-10 water year (as at 1 July

2009) ............................................................................................................................... 13 Table 2: Lower Namoi opening announcements for 2009-10 water year (as at 1 July

2009) ............................................................................................................................... 14 Table 3: Lower Namoi supplementary water announcements 2009-10 ....................................... 14 Table 4: Peel opening announcements for 2009-10 water year (as at 1 July 2009) ................... 15 Table 5: Peel off-allocation announcements 2009-10 .................................................................. 16 Table 6: Namoi and Peel water availability by licence category (all figures in ML) ...................... 17 Table 7: Upper and Lower Namoi supplementary access licences allocation

announcements 2009-10 ................................................................................................ 18 Table 8: Summary of significant water accounting policies .......................................................... 22 Table 9: Water account data accuracy estimates key .................................................................. 25

Figures Figure 1: Surface water geographical extent of the accounts.......................................................... 3 Figure 2: Groundwater area included in accounts ........................................................................... 5 Figure 3: Annual rainfall for 2009-10................................................................................................ 6 Figure 4: 2009-10 rainfall variation from long-term mean................................................................ 6 Figure 5: Monthly rainfall at Attunga during 2009-10 compared with long-term quartiles

(period of record 1903-2010). ........................................................................................... 7 Figure 6: Monthly rainfall at Narrabri during 2009-10 compared with long-term quartiles

(period of record 1870-2010). ........................................................................................... 7 Figure 7: Monthly rainfall at Walgett during 2009-10 compared with long-term quartiles

(period of record 1878-2010) ............................................................................................ 7 Figure 8: Mean maximum temperature for 2009-10 ........................................................................ 8 Figure 9: Variation in 2009-10 mean maximum temperature from long-term mean

maximum (1961-1990)...................................................................................................... 9 Figure 10: Annual inflows to Split Rock storage with the reporting period shown in red ................... 9 Figure 11: Annual flows at North Cuerindi (upstream Keepit Dam) with the reporting period

shown in red.................................................................................................................... 10 Figure 12: Annual inflows to Chaffey Dam with the reporting period shown in red ......................... 10 Figure 13: Monthly inflows to Chaffey Dam for 2009-10 compared to long-term monthly

quartiles and median (1890-2010).................................................................................. 11 Figure 14: Monthly inflows to Split Rock Dam for 2009-10 compared to long-term monthly

quartiles and median (1892-2010).................................................................................. 12 Figure 15: Physical accounting of surface water for the Peel .......................................................... 24

iii | NSW Office of Water, March 2011


iv | NSW Office of Water, March 2011

Abbreviations Acronym Description

AWAS Australian Water Accounting Standard

AWD Available Water Determination

AWR Australian Water Resources

BoM Bureau of Meteorology

CAIRO Computer Aided Improvements to River Operations

DECCW NSW Department of Environment, Climate Change and Water

ED AWAS1 Exposure Draft of Australian Water Accounting Standard 1

GIS Geographic Information System

GL Gigalitres (1,000,000,000 litres)

GMU Groundwater Management Unit

GPWAR General Purpose Water Accounting Report

IQQM Integrated Quantity and Quality Model

km kilometres

km2 square kilometres

LAS Licensing Administration System

m metre

ML megalitres (1,000,000 litres)

MODFLOW Modular Three Dimensional Finite-Difference Groundwater Flow Model

WAS Water Accounting System (Water Management Act 2000)

WASB Water Accounting Standards Board

WOU Water Ordering and Usage (Water Act 1912)


Contextual Statement

1 | NSW Office of Water, March 2011


1.1 Introduction This statement is prepared under the Exposure Draft of Australian Water Accounting Standard 1 (ED AWAS 1), as defined by the Water Accounting Standards Board (WASB).

‘The Contextual Statement shall provide information that enables users to understand the physical and administrative aspects of the water report entity. It shall contain contextual information about the water assets and water liabilities of the water report

entity, including any conditions that have an impact on the management of those water assets and water liabilities‘ Paragraph 48 (ED AWAS 1).

The contextual statement descriptive text is specific to the period being presented in the accounts,

which is 2009-10.

1.2 Namoi catchment The Namoi River system is a sub-catchment of the eastern Murray-Darling Basin. It covers a total area of about 42,000 km2 stretching 350 km from the Great Dividing Range near Tamworth to the Barwon River near Walgett. The Peel River is a major tributary to the Namoi River with a catchment area of

around 4,700 km2. It contributes an average annual volume of 280,000 ML to the Namoi River.

The Namoi catchment is bounded by the Great Dividing Range in the east, the Liverpool Ranges and Warrumbungle Ranges in the south, and the Nandewar Ranges and Mount Kaputar to the north.

Elevations range from over 1,500 m in the ranges to the south and east to just 100 m on the alluvial floodplain of the lower catchment west of Narrabri.

Major tributaries of the Namoi River include Coxs Creek and the Mooki, Peel, Manilla, and McDonald

Rivers, all of which join the Namoi upstream of Boggabri. Major tributaries of the Peel River are Goonoo Goonoo Creek, Cockburn River, and Dungowan Creek. Streamflows in the Namoi catchment are regulated by Keepit Dam on the Namoi River, Split Rock Dam on the Manilla River and Chaffey

Dam on the Peel River.

Agricultural production comprises approximately half of the regional economy. Major industries include cotton, livestock production, grain and hay, poultry and horticulture. The Peel River also provides the

bulk of urban water supply for Tamworth (supplemented by Dungowan storage located on Dungowan Creek).

Approximately 89,000 people live within the Namoi catchment, mostly along the river and its tributaries

between Tamworth and Narrabri. The largest urban centre in the valley is Tamworth, on the Peel River, which has a population of nearly 33,500 people. Other major centres are Gunnedah (7,500 people) and Narrabri (6,100 people) – both are located on the banks of the Namoi River. Smaller

towns include Barraba, Manilla, Quirindi, Walgett, Wee Waa and Werris Creek.

Significant ecological features of the catchment include the many small floodplain wetlands associated with the river, and the large internal drainage basin of Lake Goran south of Gunnedah. Extensive

areas of native woodland are conserved in the Pilliga Forest which is the largest remaining dry sclerophyll forest west of the Great Dividing Range in NSW.

More detailed information on the catchment is available in the report ‘Water resources and

management overview – Namoi catchment’ published in conjunction with this report and available on the NSW Office of Water website at www.water.nsw.gov.au.



1.3 Geographic boundaries of the Namoi water reporting entity

Surface water

Inclusions The extent included in this account is illustrated in Figure 1.

It includes the Upper Namoi Regulated River from Split Rock Dam to Keepit Dam, the Lower Namoi Regulated River from Keepit Dam to the Namoi-Barwon River confluence (including Pian and Gunidgera Creeks), the regulated Peel River from Chaffey Dam to the Peel-Namoi River confluence,

and Dungowan Creek from Dungowan Dam to the Dungowan Creek – Peel River confluence.

The water accounting statements include the licence allocation systems of the regulated Namoi catchment, including available water determinations, extractions, trading, forfeit and carryover.

Exclusions The water accounting statements do not consider unregulated water sources (other than runoff to regulated reaches), or split the water asset into storage reserves and dead storage (only total storage

volumes are considered for the account statements). While storage reserves and dead storage are not separated in the water accounting statements they do, however, form part of the reconciliations presented in the note disclosures section.

Figure 1: Surface water geographical extent of the accounts



Groundwater

Inclusions Areas for groundwater included in this General Purpose Water Accounting Report are illustrated in Figure 2. It should be noted that the methodologies used within the defined area, and also the number

of water balance parameters able to be defined, vary considerably and is dependent upon:

• whether a groundwater model is available for the area (Method A)

• for areas where a model is absent, the availability of monitoring bore data for 2009-10

(Method B or C)

Groundwater balances in the 2009-10 utilised data from methods A, B and C. Areas covered by methods A and B allow a full water balance to be achieved and include the following parameters:

• assumed groundwater volume asset

• recharge (rainfall, irrigation, flood)

• aquifer gain from river

• aquifer loss to river

• lateral flows

• pumping

• evapotranspiration.

In the areas covered by Method C, data is extremely limited and as a result only a simple balance can be achieved, with the assumption of steady state. The parameters included in the account for these

areas are

• recharge

• an estimate of pumping

• a loss or gain adjustment to maintain steady state (no volume is considered as an asset).

Further information on the selected methods can be found in Note 8.

The account data extracted from the Lower Namoi Groundwater Modular Three Dimensional Finite-Difference Groundwater Flow Model (MODFLOW) is equivalent to the Lower Namoi Groundwater Management Unit (GMU) and as such, crosses over the Namoi catchment boundary into the Gwydir

catchment.

Exclusions All non-physical groundwater transactions (available water determinations, trade, etc) have been

excluded.



Figure 2: Groundwater area included in accounts

1.4 Climate Annual rainfall for 2009-10 varied across the catchment from 500 mm at Walgett to over 1,000 mm in

the ranges along the eastern boundary of the catchment (Figure 3). The majority of the catchment received rainfall within the range of 600-800 mm for the year.

When compared to long-term rainfall trends, the rainfall anomaly for 2009-10 varied significantly

across the catchment (Figure 4). On the slopes and plains of the middle and lower catchment rainfall was either slightly higher (up to 100 mm) or significantly higher (up to 400 mm) than the long-term mean. The greatest increase in rainfall occurred in the areas of Wee Waa and Pilliga in the lower

catchment. The opposite trend occurred in the higher elevations of the eastern catchment (the storage catchment areas) where the year’s rainfall was generally less than the long-term mean by up to 100 mm. Along the top of the ranges rainfall was 100-400 mm less than average.

Rainfall across the Namoi catchment was at or below the median monthly rainfall during all months in winter and spring. At Attunga in the Peel catchment (Figure 5) conditions were generally close to the median all year, except in August which recorded rainfall in the driest quartile of all Augusts, and

December which had above average rainfall.

The wetter conditions over summer were more pronounced in the more northern parts of the catchment (Figure 6, Figure 7). At Narrabri and Walgett the period from December to March had

rainfalls that were either above average or in the wettest quartile of months recorded. The highest rainfalls occurred in December at all three sites within the catchment.



Figure 3: Annual rainfall for 2009-10

Layer source: Bureau of Meteorology

Figure 4: 2009-10 rainfall variation from long-term mean




Figure 5: Monthly rainfall at Attunga during 2009-10 compared with long-term quartiles (period of record 1903-2010).

Monthly rainfall at Attunga (near Tamworth)

0

100

200

300

400

Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun

His

toric

al r

ain

fall

(mm

/mon

th)

Wettest quartileAbove average quartileBelow average quartileDriest quartile2009–10Historical median

Figure 6: Monthly rainfall at Narrabri during 2009-10 compared with long-term quartiles (period of record 1870-2010).

Monthly rainfall at Narrabri

0

100

200

300

400

500


His

toric

al r

ain

fall

(mm

/mon

th)

Wettest quartileAbove average quartileBelow average quartileDriest quartile2009–10Historical median

Figure 7: Monthly rainfall at Walgett during 2009-10 compared with long-term quartiles (period of record 1878-2010)

Monthly rainfall at Walgett

0

100

200

300

400


His

toric

al r

ain

fall

(mm

/mon

th)

Wettest quartile

Above average quartile

Below average quartile

Driest quartile

2009–10

Historical median



The mean maximum temperature across the Namoi catchment for 2009-10 increased with decreasing elevation along a gradient from south-east to north-west across the catchment (Figure 8). Mean maximum temperatures were highest in the far north-west of the catchment around Walgett (28-29°C)

and lowest in the mountains of the Liverpool Ranges (17-18°C).

Comparing the 2009-10 mean maximum temperatures to a long-term comparative period of 1961 to 1990 shows that most areas of the catchment experienced maximum temperatures of 1-2°C higher

than the long-term mean (Figure 9). In parts of the Peel catchment and Upper Namoi mean maximum temperatures were up to 5°C higher than the long-term maximums.

Figure 8: Mean maximum temperature for 2009-10




Figure 9: Variation in 2009-10 mean maximum temperature from long-term mean maximum (1961-1990)


Figure 10: Annual inflows to Split Rock storage with the reporting period shown in red

Long-term Split Rock Inflows (Simulated + Backcalculated)

0

100

200

300

400

500

1893

1897

1901

1905

1909

1913

1917

1921

1925

1929

1933

1937

1941

1945

1949

1953

1957

1961

1965

1969

1973

1977

1981

1985

1989

1993

1997

2001

2005

2009

ML

x 1

000

01/07/1893 - 30/06/2010

01/07/2009 - 30/06/2010

Average



Figure 11: Annual flows at North Cuerindi (upstream Keepit Dam) with the reporting period shown in red

Namoi River at North Cuerindi Flow (Observed and Simulated)

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

18

93

18

98

19

03

19

08

19

13

19

18

19

23

19

28

19

33

19

38

19

43

19

48

19

53

19

58

19

63

19

68

19

73

19

78

19

83

19

88

19

93

19

98

20

03

20

08

ML

x 1

000

01/07/2009 - 30/06/2010

01/07/1892 - 30/06/2009

Average

Figure 12: Annual inflows to Chaffey Dam with the reporting period shown in red

Long-term Chaffey Inflows (Simulated + Backcalculated)

0

50

100

150

200

250

189

2

189

7

190

2

190

7

191

2

191

7

192

2

192

7

193

2

193

7

194

2

194

7

195

2

195

7

196

2

196

7

197

2

197

7

198

2

198

7

199

2

199

7

200

2

200

7

ML

x 1

000

01/07/1892 - 30/06/2010

01/07/2009 - 30/06/2010

Average



Figure 10 and Figure 12 provide historical and simulated annual inflows to both Split Rock and Chaffey Dams. Figure 11 shows historical and simulated flows in the Namoi River at North Cuerindi which provides a good representation of the trends in the catchment above Keepit Dam. All of these

figures indicate that annual inflows to Split Rock, Keepit and Chaffey Dams were below average for the 2009-10 season. All of these storages have had at least nine consecutive years of below average inflow, with the last time the average was exceeded being in the 2000-01 season.

A comparison of the 2009-10 monthly inflow sequence for Chaffey Dam against long-term inflows (produced by storage back calculation data combined with rainfall runoff modelling for the pre-dam period), indicates that inflows were below the median inflow for the first six months of the season

(Figure 13)

Runoff events in January 2010 were much higher than the median, falling in the mid-range of the ‘wet’ quartile. Inflows from February to June 2010 were generally around the long-term median.

The 2009-10 monthly inflows to Split Rock storage compared to long-term inflows (Figure 14) illustrates the significantly low runoff that occurred in this catchment. Recorded inflows fell within the dry quartile for all months except for January, where summer rainfall events increased runoff to above

average.

Figure 13: Monthly inflows to Chaffey Dam for 2009-10 compared to long-term monthly quartiles and median (1890-2010)

Monthly Chaffey Inflows (logarithmic scale)

1

10

100

1000

10000

100000

July August September October November December January February March April May June

ML

/Mo

nth

WetAbove averageBelow averageDry2009–10Median



Figure 14: Monthly inflows to Split Rock Dam for 2009-10 compared to long-term monthly quartiles and median (1892-2010)

Monthly Split Rock Inflows (logarithmic scale)

1

10

100

1000

10000

100000

July August September October November December January February March April May June

ML

/Mo

nth

WetAbove averageBelow averageDry2009–10Median

1.5 Policy The Upper and Lower Namoi regulated surface water and groundwater systems operate under water sharing plans that have been prepared under the Water Management Act 2000. The plans in place for

the 2009-10 season were:

Water Sharing Plan for the Upper Namoi and Lower Namoi Regulated River Water Sources

• Water Sharing Plan for the Upper and Lower Namoi Groundwater Sources

• Water Sharing Plan for the NSW Great Artesian Basin Groundwater Sources

The Peel regulated surface water and ground water system continued to operate under the Water Act 1912 as the recently commenced water sharing plan was not in place for the 2009-10 season.

In addition State Water Corporation was required to operate the water supply works in accordance with the Water Supply Work Approval for the Namoi catchment.

A protocol for the bulk water transfer from Split Rock Dam to Keepit Dam, containing operating

considerations for minimising adverse environmental impacts, was applicable for the 2009-10 water year.

1.6 Management

Surface water

Upper Namoi regulated water source While basic rights, domestic and stock, local water utilities and high security licences started the year with 100 per cent of entitlements the initial general security announcement was restricted to

50 per cent. This combined with a carryover of unused water from the previous water year of approximately 12 per cent resulted in a starting water availability of approximately 62 per cent. The continuation of drought conditions resulted in no further allocation increases and very little ‘new water’

becoming available in Split Rock Dam. Table 1 illustrates the opening announcements for the Upper Namoi regulated river on 1 July 2009.



With the extremely dry conditions and a corresponding lack of flows in the Macdonald River, in late December the township of Manilla switched access for town water supply from the Macdonald River to the Namoi River utilising their entitlement held on the Upper Namoi. Rainfall at the end of December

resulted in flows returning to the Macdonald River, limiting the required access from the Namoi River to just seven days.

Table 1: Upper Namoi opening announcements for 2009-10 water year (as at 1 July 2009)

Date Individual

Announcement Entitlement

Allocation Volume

(ML)

AnnouncedPercent of Entitlement

Balance Available

(ML)

Non AvailableBalance

(ML)

BalanceTotal (ML)

Domestic And Stock

Opening 76 0 0 0

1 July 2009 AWD 100.0 % 76 76 100.00% 76 0 76

Domestic And Stock(Domestic)

Opening 11 0 0 0

1 July 2009 AWD 100.0 % 11 11 100.00% 11 0 11

Domestic And Stock(Stock)

Opening 5 0 0 0

1 July 2009 AWD 100.0 % 5 5 100.00% 5 0 5

Local Water Utility

Opening 150 0 0 0

1 July 2009 AWD 100.0 % 150 150 100.00% 150 0 150

Regulated River (General Security)

Opening 9,724 1,150 0 1,150

1 July 2009 AWD 0.5 ML per Share 9,724 4,862 50.00% 6,012 0 6,012

Regulated River (High Security)

Opening 80 0 0 0

1 July 2009 AWD 1.0 ML per Share 80 80 100.00% 80 0 80

Lower Namoi regulated water source While basic rights, domestic and stock, local water utilities and high security licences started the year with 100 per cent of entitlements no general security announcement was possible due to continued drought conditions. However, the continuous accounting allocation scheme in place meant that

approximately 25 per cent of entitlement was carried forward from the previous water year. The continuation of drought conditions throughout the season meant that no further allocation announcements were made, very little ‘new water’ became available in Split Rock and Keepit Dams

and no bulk water transfers between Split Rock and Keepit Dams were conducted. Table 2 illustrates the opening announcements for the Lower Namoi regulated river on 1 July 2009.

During the season, as a result of the continuation of the dry conditions and hence the low volumes of

water to be delivered, Keepit Dam releases were undertaken using a block release strategy in order to minimise delivery losses.

The supplementary water announcement was maintained at 100 per cent of entitlement. During the

year two periods of supplementary water were declared starting on the 29 December 2009 and 14 February 2010 respectively. The Lower Namoi supplementary water announcements are split into A and B Class where A Class entitlements are required to be made fully available prior to B Class

being declared. Table 3 provides a summary of the supplementary announcements made.



The Lower Namoi is required to provide up to 14,000 ML over two replenishments for the Pian Creek System down to Dundee Weir. In 2009–10 two replenishment events were provided for the periods 18 September 2009 to 15 October 2009 and 12 January 2010 to 22 March 2010.

Table 2: Lower Namoi opening announcements for 2009-10 water year (as at 1 July 2009)

Date Individual


Allocation Volume

(ML)


Balance Available

(ML)

Non AvailableBalance

(ML)

BalanceTotal (ML)

Domestic And Stock

Opening 1,745 0 0 0

1 July 2009 AWD 100.0 % 1,745 1,745 100.00% 1,744 0 1,744


Opening 20 0 0 0

1 July 2009 AWD 100.0 % 20 20 100.00% 20 0 20


Opening 257 0 0 0

1 July 2009 AWD 100.0 % 257 257 100.00% 257 0 257

Local Water Utility

Opening 2,271 0 0 0

1 July 2009 AWD 100.0 % 2,271 2,271 100.00% 2,271 0 2,271


Opening 246,212 60,134 904 61,038


Opening 3,418 0 0 0


Regulated River (High Security)(Research)

Opening 486 0 0 0

1 July 2009 AWD 1.0 ML per Share 486 486 100.00% 486 0 486

Supplementary Water

Opening 115,469 0 0 0


Table 3: Lower Namoi supplementary water announcements 2009-10

Start Date

Access Licence Class

Percent Entitlement Available

Days Pumping Permitted

River/Stream River Section

From River Section

To

29/12/2009 A 100% 8 Namoi River Peel River Junction Gunidgera Weir

29/12/2009 B 100% 8 Pian Creek All All

29/12/2009 A 92% 8 Namoi River Peel River Junction Gunidgera Weir

29/12/2009 B 92% 8 Pian Creek All All

29/12/2009 A 100% 11 Namoi River Gunidgera Weir Bugilbone

29/12/2009 B 100% 11 Namoi River Gunidgera Weir Bugilbone

29/12/2009 A 100% 13 Namoi River Bugilbone Walgett

29/12/2009 B 100% 13 Namoi River Bugilbone Walgett

14/02/2010 A 100% 3 Namoi River Goangra Walgett

14/02/2010 B 25% 3 Namoi River Goangra Walgett



Peel regulated water source At the commencement of the 2009-10 season domestic and stock, local water utility and high security all received 100 per cent of entitlement with general security receiving 80 per cent of entitlement

(Table 4).

Table 4: Peel opening announcements for 2009-10 water year (as at 1 July 2009)

Date Individual


Allocation Volume

(ML)


Balance Available

(ML)

Non Available Balance

(ML)

BalanceTotal (ML)

Domestic And Stock

Opening 85 0 0 0

1-Jul-09 AWD 100 % 85 85 100.0% 85 0 85


Opening 72 0 0 0

1-Jul-09 AWD 100 % 72 72 100.0% 72 0 72


Opening 20 0 0 0

1-Jul-09 AWD 100 % 20 20 100.0% 20 0 20

Local Water Utility

Opening 16,400 0 0 0

1-Jul-09 AWD 100 % 16,400 16,400 100.0% 16,400 0 16,400


Opening 30,911 0 0 0

1-Jul-09 AWD 80% 30,911 24,729 80.0% 24,729 0 24,729


Opening 801 0 0 0

1-Jul-09 AWD 100 % 801 801 100.0% 801 0 801


Opening 3 0 0 0

1-Jul-09 AWD 100 % 3 3 100.0% 3 0 3

While no supplementary water licences were in place under the Water Act 1912 access to high flows was available via off-allocation announcements. The off-allocation announcements for the Peel are shown in Table 5.



Table 5: Peel off-allocation announcements 2009-10

Start Date

Finish Date

River/Stream River Section From River Section To

25/11/2008 Peel Woolomin Bridge Namoi Junction

03/12/2008 Peel Chaffey Dam Namoi Junction

12/01/2009 Peel Chaffey Dam Woolomin Bridge

15/01/2009 Peel Chaffey Dam Paradise Weir


23/02/2009 05/03/2009 Peel Paradise Weir Namoi Junction

29/06/2009 13/07/2009 Peel Tamworth Pumps Namoi Junction

17/07/2009 Peel Woolomin Bridge Namoi Junction



08/09/2009 22/09/2009 Peel Chaffey Dam Namoi Junction

24/09/2009 06/10/2009 Peel Chaffey Dam Namoi Junction


20/01/2010 Peel Chaffey Dam Woolomin Bridge


16/02/2010 26/02/2010 Peel Paradise Weir Namoi Junction

01/06/2010 Peel Paradise Weir Namoi Junction




Water availability Detailed information on total volumes of water allocated throughout the year can be obtained in the statements and associated notes of this report. A summary of the water made available to be

extracted in the reporting period is illustrated in Table 6. It should be noted that supplementary water can only be accessed during specific flow events and therefore it is not represented in the table as having a volume of water made available.

The Lower Namoi regulated general security licences are allowed to accumulate account water up to 200 per cent of their entitlement. Annual extraction restrictions of 100 per cent of entitlements mean that some water is not available to access in the reporting period.

Table 6: Namoi and Peel water availability by licence category (all figures in ML)

Water Availability 2009-10

Licence Category

Carried Forward

From 2008-09

Available Water

Determination2009-10 Available

Non Available

Upper Namoi Water Source

Domestic And Stock 0 76 76 0

Domestic And Stock [Domestic] 0 11 11 0

Domestic And Stock [Stock] 0 5 5 0

Local Water Utility 0 150 150 0

Regulated River (General Security) 1,150 4,862 6,012 0

Regulated River (High Security) 0 80 80 0

Lower Namoi Water Source

Domestic And Stock -1 1,745 1,744 0



Local Water Utility 0 2,271 2,271 0

Regulated River (General Security) 61,038 1,418 61,547 909

Regulated River (High Security) 0 3,418 3,418 0

Regulated River (High Security) [Research] 0 486 486 0

Supplementary Water 0 115,469 115,469 0

Peel Water Source

Domestic And Stock 0 85 85 0



Regulated River (General Security) 0 30,911 30,911 0

Regulated River (High Security) 0 801 801 0

Regulated River (High Security) [Research] 0 3 3 0

Local Water Utility 0 16,400 16,400 0



Groundwater

Monitoring bore data in Lower Namoi GMU indicate that from 2006 to 2010 groundwater levels are trending upward in the western and central area of the Lower Namoi GMU and downward in the eastern end of the GMU. Three selected monitoring bores in the Upper Namoi GMU show a falling

trend at two locations and a steadier trend, although with high variability at the third. Selected bores in the Peel Alluvium indicate that while variation is high the levels have remained relatively steady. This pattern is indicative of the Peel catchment’s highly connected surface and groundwater systems which

are also supported by the modelling work presented in this GPWAR. For more detail refer to Note 3 of this report.

All groundwater licences in the Namoi catchment were granted an equivalent allocation of

100 per cent, with the exception of supplementary groundwater access licences for which the allocation varies in each of the groundwater management zone between 60 per cent and 100 per cent. Under the terms set out in the Water Sharing Plan for the Upper and Lower Namoi Groundwater Sources the volume of supplementary water made available will progressively be reduced to zero by 2015-16. The volume of supplementary water announced for 2009-10 is detailed in the following table. This category of licence was introduced to return extractions within the aquifers to a sustainable level

over the life of the water sharing plan. The Peel contains no supplementary groundwater licences as no water sharing plan was in place for the 2009-10 water year.

Table 7: Upper and Lower Namoi supplementary access licences allocation announcements 2009-10

Water Source Groundwater Management Zone ML per share

Upper Namoi Upper Namoi Zone 1 Borambil Creek Groundwater Source 0.76

Upper Namoi Upper Namoi Zone 2 Cox's Creek (Mullaley To Boggabri) Groundwater Source

0.60

Upper Namoi Upper Namoi Zone 3 Mooki Valley (Breeza To Gunnedah) Groundwater Source

0.60

Upper Namoi Upper Namoi Zone 4 Namoi Valley (Keepit Dam To Gin's Leap) Groundwater Source

0.60

Upper Namoi Upper Namoi Zone 5 Namoi Valley (Gin's Leap To Narrabri) Groundwater Source

1.00

Upper Namoi Upper Namoi Zone 6 Tributaries Of The Liverpool Range (South To Pine Ridge Road) Groundwater Source

N/A

Upper Namoi Upper Namoi Zone 7 Yarraman Creek (East Of Lake Goran To Mooki River) Groundwater Source

1.00

Upper Namoi Upper Namoi Zone 8 Mooki Valley (Quirindi - Pine Ridge Road To Breeza) Groundwater Source

0.60

Upper Namoi Upper Namoi Zone 9 Cox's Creek (Up-Stream Mullaley) Groundwater Source

N/A

Upper Namoi Upper Namoi Zone 10 Warrah Creek Groundwater Source N/A

Upper Namoi Upper Namoi Zone 11 Maules Creek Groundwater Source 1.00

Upper Namoi Upper Namoi Zone 12 Kelvin Valley Groundwater Source 1.00

Lower Namoi Lower Namoi Groundwater Source 0.60

N/A indicates there are no supplementary licences in the zone



1.7 Environmental water

Held environmental water

Held environmental water represents water that is held as part of a licensed volumetric entitlement. In 2009-10 held environmental water increased from a total share component of 3,833 to 6,203 ML (an

increase of 2,370 ML).

In addition, a volume of 53 ML of environmental water was traded from the Upper to Lower Namoi. The Peel water source contains no environmental licences. For detailed breakdown of held

environmental water and traded water refer to Note 19.

Planned environmental water

The water sharing plan provides for minimum flows at Walgett to be maintained at about 21 ML/day in June, 24 ML/day in July, and 17 ML/day in August when the sum of the water stored in Keepit Dam

and Split Rock Dam exceeds 120,000 ML. For the months of July and August 2009 the minimum flow was met satisfactorily. However, while the combined storage volume in Keepit and Split Rock Dams was above 120,000 ML at the start of June 2010, the requirement for the end of system flow was

suspended. For more detail refer to Note 12.



Water Accounting Statements



Water Accounting Statement Descriptions

The water accounting statements required under ED AWAS 1 comprise three statements that were produced using double entry accounting:

• Statement of Water Assets and Water Liabilities as 30 June 2010

• Statement of Changes in Water Assets and Water Liabilities for 1 July 2009 to 30 June 2010

• Statement of Physical Flows for 1 July 2009 to 30 June 2010.

Separate statements have been produced for the Namoi and Peel systems.

Statement of Water Assets and Water Liabilities The Statement of Water Assets and Water Liabilities is prepared under the ED AWAS 1, as defined by the Water Accounting Standards Board.

’The Statement of Water Assets and Water Liabilities shall provide information that

enables users to understand the nature and volumes of the water assets and water liabilities of a water report entity‘ (paragraph 58, WASB 2010).

In line with the above statement, this report provides an assessment of the water available in storage

plus any current claims to water (water assets). This is offset by any present obligations (water liabilities) that are required to be met with these water assets. Figures from the previous reporting period are also provided to add context. All figures are in ML.

Water assets Water assets for the reporting entity include not only physical water in storage, but also any claims to water that are expected to increase the future water resource. Other claims would be applicable where

the entity is owed water from another external entity (e.g. intervalley trading). Currently there are no claims to water applicable for the Namoi water report entity.

Water liabilities Water liabilities represent claims on the water assets of the water report entity. This is most apparent in water that has been allocated to licence holder accounts or environmental accounts but yet to be taken at the end of the reporting period (account water allowed to be carried forward to the next water

year). As such the figures represent the closing balances of these accounts for the reporting period. It is important to note that some accounts may be shown as a negative number. An example of this is when more usage has occurred than has been allocated to the licence holder’s account. As a result

the negative account balance is required to be carried over to the next water year. Under the ED AWAS 1 this example could also be represented as a positive value in the water assets. However, for the intent of this GPWAR it was considered that it is more informative to present all the licence

allocation account balances together. It should be noted that no groundwater liabilities were accounted for in the statements.

Net water assets Net water assets is a calculated figure of total water assets minus total water liabilities.

Table 8 provides a summary of the assignment policy for both physical and non-physical components of the water account.



Table 8: Summary of significant water accounting policies

Surface water Groundwater

Water assets Water liabilities Water assets Water liabilities

Major storages Licensed allocation balance (carryover)

Extractable storage estimate (Method A and B area)

Major weirs

River volume

Total water assets Total water liabilities Total water assets Total water liabilities

NET WATER ASSETS

All components defined in detail in the note disclosures section of this document

Statement of Changes in Water Assets and Water Liabilities The Statement of Changes in Water Assets and Water Liabilities is prepared under the ED AWAS 1,

as defined by the Water Accounting Standards Board.

’The Statement of Changes in Water Assets and Water Liabilities shall contain information that enables users to understand changes in the volumes and nature of

the water report entity’s net water assets during the reporting period‘ (paragraph 101, WASB 2010).

The report comprises both physical and non-physical transactions, and illustrates how the change in

net water assets from the previous reporting period has eventuated. Figures from the previous reporting period are also provided in order to put the change into context. Internal trades have a net zero effect on the resources as a whole and therefore appear in both the water increases (buyers) and

water decreases (sellers). All figures are in ML.

Water asset increases Account items that have an increasing effect on the water assets presented in the Statement of Water

Assets and Water Liabilities e.g. tributary inflows and rainfall.

Water asset decreases Account items that have a decreasing effect on the water assets presented in the Statement of Water

Assets and Water Liabilities e.g. evaporation and groundwater pumping.

Water liability increases Account items that have an increasing effect on the water liabilities presented in the Statement of

Water Assets and Water Liabilities e.g. available water determinations increase the amount of water available in the allocation liability accounts.

Water liability decreases Account items that have a decreasing effect on the water liabilities presented in the Statement of Water Assets and Water Liabilities e.g. forfeited water reduces the amount of water available in the allocation liability accounts.



Change in net water assets The figure in respect of change in net water assets is calculated as:

+=Δ WLDWLIWADWAINWA

Where NWA = Net water assets

WAI = Water asset increases

WAD = Water asset decreases

WLI = Water liability increases

WLD = Water liability decreases

The resultant net change should be equal to the annual change in net water asset on the Statement of Water Assets and Water Liabilities i.e. {Net Water Asset [Reporting Year] minus Net Water Asset [Reporting Year-1]}

Statement of Physical Water Flows The Statement of Physical Water Flows is prepared under the ED AWAS 1, as defined by the Water Accounting Standards Board.

’The Statement of Physical Water Flows shall contain information that enables users to understand the nature and volumes of physical water flows experienced by the water report entity during the reporting period‘ (paragraph 109, WASB 2010).

This report is reminiscent of traditional water balance reporting whereby only physical volumes of water in storage, and physical movement in and out of storage are considered. All figures are in ML.

Water in storage Water in storage includes the volume of major regulated storages and weirs, the estimated volume within the regulated river, and the assumed groundwater volume for Method A and Method B accounting areas (see Note 3) at the end of the reporting period.

Inflows Inflows are physical inflows to storage within the reporting entity e.g. tributary inflow, inflow from groundwater.

Outflows Outflows are physical outflows from storage within the reporting entity e.g. diversions, evaporation.

Net inflow Total inflow – total outflow – Unaccounted-for difference = Change in water storage

The significant water accounting policies used to achieve the physical accounting balance is illustrated in Figure 15 (Peel) and Figure 16 (Namoi). As shown in these figures storage outflows are accounted

as a transfer of asset and as such do not appear directly in the statements. The end of system flow for the Peel (recorded flows for Peel River at Carrol Gap) corresponds to an inflow (water asset increase) to the Namoi.

As the Upper and Lower Namoi is accounted for as one entity, Keepit is an on-river storage, whereby inflows are a transfer from the Upper Namoi River and as such do not directly appear in the statements. The Upper Namoi River asset is from the Manilla River downstream of Split Rock to the

Namoi River upstream of Keepit Dam. The Namoi River upstream of the Manilla-Namoi junction is not part of the river asset, but part of the tributary inflow contribution to the system.




Figure 15: Physical accounting of surface water for the Peel

Chaffey Storage

Storage outflow (water asset transfer)

Tributary inflow (Cockburn River, Goonoo Goonoo Creek, ungauged estimate), rainfall

Evaporation, extractions

River

Chaffey inflow

Rainfall

Evaporation

Rainfall

Dungowan inflow

Evaporation

Dungowan Storage

Peel River at Carrol Gap (input to Namoi balance)


Figure 16: Physical accounting of surface water for the Namoi

Split Rock Storage


Keepit inflow (water asset transfer)

Keepit Storage

Tributary inflow (Namoi River, Halls Creek, ungauged estimate), rainfall

Split Rock inflow (Manilla River)

Evaporation, extractions

Tributary Inflow (Peel, Mooki, Coxs,Briglow,Maules, ungauged estimate), rainfall, aquifer to river

Evaporation, extractions, river to aquifer

Namoi River at Walgett

Keepit outflow (water asset transfer)

River (Upper)

River (Lower)

Rainfall

Evaporation

Rainfall

Evaporation

Data accuracy It is important to recognise that the data used to account for water movement and management in the Namoi and Peel has been obtained from a variety of sources and systems. The data ranges from observed values where a high accuracy would be anticipated through to modelled results and

estimates where accuracy can be highly variable depending on a range of factors. To address the inconsistencies in accuracy and prevent misuse of the data in the accounts, all figures in the water accounting statements will be accompanied by an assessment of accuracy as defined in Table 9.


Table 9: Water account data accuracy estimates key

Accuracy code Estimated accuracy range

A +/- 10%

B +/- 25%

C +/- 50%

D +/- 100%

In addition to an accuracy code each figure in the accounts is cross-referenced where appropriate to a numerically linked note where detailed information can be found relating to that figure. The notes form part of the note disclosures of this GPWAR. The information contained in the notes is reported

according to the following structure:

• brief description

• data type

• policy

• data accuracy

• providing agency

• data source

• methodology

• additional information (if applicable).

Other statement descriptions

Two additional statements are required under ED AWAS 1:

• Accountability Statement

• Assurance Statement.

Accountability Statement The Accountability Statement is prepared under the ED AWAS 1, as defined by the Water Accounting Standards Board.

’The Accountability Statement shall provide information that assists users to assess whether: the general purpose water accounting report has been prepared and presented in accordance with Australian Water Accounting Standards; externally-

imposed requirements relevant to managing the water assets and water liabilities of the water report entity have been complied with; and best practices for managing water assets and water liabilities have been applied.’ (Paragraph 50 WASB, 2010)

The statement details externally imposed requirements relevant to and best practice for management of the water reporting entity for the reporting period.

Assurance Statement The Assurance Statement is prepared under the ED AWAS 1, as defined by the Water Accounting Standards Board.

’An explicit statement of whether the general purpose water accounting report is

presented fairly in accordance with this standard shall be provided in the Assurance Statement‘ (paragraph 167, WASB 2010).

No specific Assurance Statement has been included in this report (see specific section on Assurance

Statement in this report for more details).



Namoi catchment

Accountability Statement

In the opinion of the undersigned:

1. The management of the water assets and water liabilities of the Namoi water report entity have been conducted throughout 2009-10 under the required externally-imposed requirements, including:

• Water Management Act 2000

• Water Act 1912

• Water Sharing Plan for the Upper Namoi and Lower Namoi Regulated River Water

Sources

• Water Sharing Plan for the Upper and Lower Namoi Groundwater Sources

• Murray-Darling Basin Agreement 2000

2. The management of the water source has been carried out by qualified and experienced staff who have undertaken the task with due diligence.

3. The Water Sharing Plan for the Upper Namoi and Lower Namoi Regulated Water Sources, the Water Sharing Plan for the Phillips Creek, Mooki River, Quirindi Creek and Warrah Creek Water Sources, and the Water Sharing Plan for the Upper and Lower Namoi Groundwater Sources incorporate the following best practice management principles:

• water sharing and extraction limitations

• trading of water rights

• basic landholder rights

• water planning and strategic initiatives

• environmental stewardship.

4. The information presented in these accounts is a faithful representation of the management and operation of the Namoi catchment in 2009-10.

5. NSW Office of Water has to the best of its ability prepared the General Purpose Water Accounting Report for the Namoi water report entity for the 2009-10 water year in accordance with the ED AWAS 1.



Peel catchment Statement of Water Assets and Water Liabilities For the year ended 30 June 2010

WATER ASSETS (ML) Accuracy Notes 30 June 2010 30 June 2009

SURFACE WATER ASSETS

Surface Water Storage Chaffey Dam A 1 55,484 59,789Dungowan Dam A 1 5,412 6,116River B 2 179 136

Total Surface Water Storage 61,075 66,041 TOTAL SURFACE WATER ASSETS 61,075 66,041

GROUNDWATER ASSETS

Peel Alluvium D 3 40,940 44,660

TOTAL WATER ASSETS 102,015 110,701

WATER LIABILITIES

WATER LIABILITIES 0 0

TOTAL WATER LIABILITIES 0 0

NET WATER ASSETS 102,015 110,701 CHANGE IN NET WATER ASSETS (8,686) 18,146



Peel catchment Statement of Changes in Water Assets and Water Liabilities For the year ended 30 June 2010 (1 of 2)

SURFACE WATER (ML) Accuracy Notes 30 June 2010 30 June 2009

WATER ASSET INCREASES

Physical Inflows Dungowan Inflow A 5 6,466 11,255Chaffey Dam Inflow A 5 24,863 47,019Gauged Inflow A 6 25,191 73,033Ungauged Inflow C 7 43,841 127,105River inflow from Aquifer (Method 'A' D 8 20,820 83,200Rainfall

Chaffey B 10 4,266 4,335Dungowan B 10 392 437River C 11 1,111 4,718

TOTAL WATER ASSET INCREASES 126,950 351,102

WATER ASSET DECREASES Physical Outflows

Evaporation Chaffey Dam B 10 9,262 9,091Dungowan Dam B 10 842 911River C 11 2,177 4,465

End of System Flow A 12 50,469 225,676Off allocation diversions A 13 4,845 2,622Dungowan pipeline diversion A 2,030 2,449Basic Rights C 15 299 299River outflow to Aquifer (Method 'A' D 8 35,590 83,900Unaccounted-for difference D 17 13,690 641

TOTAL WATER ASSET DECREASES 119,204 330,054

WATER LIABILITY INCREASES Available Water Determinations A 16

Domestic and Stock 177 177General Security 30,911 24,729High Security 801 801High Security (Research) 3 3Local Water Utility 16,400 16,400

Internal Trade - Buyers A 9 159 96

TOTAL WATER LIABILITY INCREASES 48,451 42,206

WATER LIABILITY DECREASES

Account Forfeiture A 4 Domestic and Stock 78 102General Security 25,093 21,578High Security 682 704High Security (Research) 3 0Local Water Utility 9,724 12,164

Internal Trade - Sellers A 9 159 96

TOTAL WATER LIABILITY DECREASES 35,739 34,644

NET CHANGE IN SURFACE WATER ASSETS (4,966) 13,486



Peel catchment Statement of Changes in Water Assets and Water Liabilities For the year ended 30 June 2010 (2 of 2)

GROUNDWATER (ML) Accuracy Notes 30 June 2010 30 June 2009

WATER ASSET INCREASES D 8

Physical Inflows Peel Alluvium

Aquifer Inflow from River 35,590 83,900Recharge (Irrigation) 1,590 1,080Recharge (Rainfall) 12,150 27,570

Peel Fractured Rock Recharge (Rainfall) 291,000 344,000Seepage from Alluvium 23,450 18,370


WATER ASSET DECREASES

Physical Outflows D 8

Peel Alluvium Pumping 7,930 5,420Aquifer outflow to River 20,820 83,200Evapotranspiration 850 900Seepage to Fractured Rock 23,450 18,370

Peel Fractured Rock Unaccounted-for difference D 17 314,450 362,370

TOTAL WATER ASSET DECREASES 367,500 470,260

NET CHANGE IN GROUNDWATER ASSETS (3,720) 4,660

Total Water Asset Increases 490,730 826,022Total Water Asset Decreases 486,704 800,314Total Water Liability Increases 48,451 42,206Total Water Liability Decreases 35,739 34,644

CHANGE IN NET WATER ASSETS (8,686) 18,146



Peel catchment Statement of Physical Flows Water year ending 30 June 2010 (1 of 2)

SURFACEWATER (ML)

Water in Storage Accuracy Notes 30 June 2010 30 June 2009 Chaffey Dam A 1 55,484 59,789Dungowan Dam A 1 5,412 6,116River C 2 179 136

Total Water in Storage 61,075 66,041

CHANGE OF WATER IN STORAGE (4,966)

Inflows

Chaffey Dam Inflow A 5 24,863 47,019Dungowan Dam Inflow A 5 6,466 11,255Gauged Inflow A 6 25,191 73,033Ungauged Inflow C 7 43,841 127,105Rainfall

Chaffey Dam B 10 4,266 4,335Dungowan Dam B 10 392 437River C 11 1,111 4,718

River inflow from Aquifer D 8 20,820 83,200

Total Inflows 126,950

Outflows

Extractions Domestic and Stock 99 99General Security 5,818 5,818High Security (HS) 119 119Local Water Utility 6,676 6,676Basic Rights 299 299Off Allocation Diversions A 5 4,845 2,622

Flow Leaving End of System Flow A 6 50,469 225,676

Losses Evaporation

Chaffey Dam B 10 9,262 9,091Dungowan Dam B 10 842 911River C 11 2,177 4,465

River outflow to Aquifer D 8 35,590 83,900

Other outflows Dungowan Pipeline Diversion A 21 2,030 2,449

Total Outflows 118,226 225,676

Unaccounted-for difference 13,690 641

NET INFLOW (4,966)



Peel catchment Statement of Physical Flows Water year ending 30 June 2010 (2 of 2)

GROUNDWATER (ML)

Water in Storage Accuracy Notes 30 June 2010 30 June 2009

Method 'A' Area (Peel Alluvium) Peel Alluvium D 3 40,940 44,660


Inflows D 8 Aquifer Inflow from River 35,590 83,900Recharge (Irrigation) 1,590 1,080Recharge (Rainfall) 12,150 27,570


Outflows D 8 Aquifer outflow to River 20,820 83,200Evapotranspiration 850 900Pumping 7,930 5,420Seepage to Fractured Rock 23,450 18,370

Total Outflows 53,050

NET INFLOW (3,720)

Method 'C' Area (Fractured rock)

Inflows D 8 Rainfall Recharge 291,000 344,000Seepage from Alluvium 23,450 18,370

Outflows D 8 Unaccounted-for difference D 17 314,450 362,370

NET INFLOW 0



Namoi catchment Statement of Water Assets and Water Liabilities For the year ended 30 June 2010

WATER ASSETS (ML) Accuracy Notes 30 June 2010 30 June 2009

SURFACE WATER ASSETS

Surface Water Storage Split Rock Dam A 1 13,685 21,237Keepit Dam A 1 120,480 156,050Gunidgera Weir A 1 1,214 1,489Mollee Weir A 1 98 700River C 2

Upper 54 171Lower 234 3,444

Total Surface Water Storage 135,765 183,091 TOTAL SURFACE WATER ASSETS 135,765 183,091

GROUNDWATER ASSETS D 3

Upper Namoi (Method 'A' Area) 201,458 188,459Lower Namoi (Method 'A' Area) 191,200 207,700

TOTAL GROUNDWATER ASSETS 392,658 396,159

TOTAL WATER ASSETS 528,423 579,250

WATER LIABILITIES

SURFACE WATER LIABILITIES A 4

Upper Namoi General Security 2,235 1,150Lower Namoi Domestic and Stock (D&S) 0 (1)General Security 36,048 61,038

TOTAL SURFACE WATER LIABILITIES 38,282 62,187

TOTAL WATER LIABILITIES 38,282 62,187

NET WATER ASSETS 490,141 517,063




Namoi catchment Statement of Changes in Water Assets and Water Liabilities For the year ended 30 June 2010 (1 of 2)

SURFACE WATER (ML) Accuracy Notes 30 June 2010 30 June 2009


Physical Inflows Split Rock Dam Inflow A 5 3,857 6,952Gauged Inflow A 6

Upper 43,895 163,423Lower

Inflow from Peel (Carroll Gap) 50,469 225,676Other Gauges 115,070 106,210

Ungauged Inflow C 7 Upper 8,600 32,000Lower 189,940 119,000

Rainfall Keepit Dam B 10 7,724 12,005Split Rock Dam B 10 1,077 2,553River (Upper) C 11 1,051 1,611River (Lower) C 11 12,951 9,976

River Inflow from Aquifer D 8 3,710 3,093


WATER ASSET DECREASES

Physical Outflows Evaporation

Split Rock Dam B 10 4,732 5,613Keepit Dam B 10 29,742 27,486River (Upper) C 11 3,631 3,355River (Lower) C 11 24,065 26,283

End of System Flow A 12 264,739 115,073Supplementary Licenced Extractions A 14 39,786 62,860Basic Rights Extractions C 15

Upper 160 160Lower 1,776 1,776

River Outflow to Aquifer D 8 54,950 58,587Unaccounted-for difference D 17 27,663 287,178TOTAL WATER ASSET DECREASES 451,244 588,371WATER LIABILITY INCREASES Available Water Determinations A 16

Upper Domestic and Stock 92 92General Security 4,862 4,862High Security 80 80Local Water Utility 150 150

Lower Domestic and Stock 2,022 2,030General Security 1,418 58,500High Security 3,418 3,418High Security (Research) 486 486Local Water Utility 2,271 2,271

Internal Trade – Buyers A 9 12,223 9,204TOTAL WATER LIABILITY INCREASES 27,022 81,093

WATER LIABILITY DECREASES

Account Forfeiture A 4 Upper

Domestic and Stock 86 84General Security 313 42High Security 51 67Local Water Utility 136 145

Lower Domestic and Stock 1,338 1,045General Security 218 392High Security 128 122Local Water Utility 1,424 1,501

Water Order Debiting (Orders > Usage) A 20 Domestic and Stock 25 8General Security 558 352

High Security 1 0Internal Trade – Sellers A 9 12,223 9,204TOTAL WATER LIABILITY DECREASES 16,501 12,962



Namoi catchment Statement of Changes in Water Assets and Water Liabilities For the year ended 30 June 2010 (2 of 2)

GROUND WATER (ML) Accuracy Notes 30 June 2010 30 June 2009


Physical Groundwater Inflows D 8 Method 'A' Accounting Area

Lateral Flows (Boundary) 14,730 14,747Recharge - Irrigation 27,241 26,641Recharge - Rain 46,283 51,245Aquifer Inflow from River 54,950 58,587

Method 'C' Accounting Area Recharge 1,162,000 601,000

TOTAL WATER ASSET INCREASES 1,305,204 752,220 WATER ASSET DECREASES

Physical Groundwater Outflows D 8

Method 'A' Accounting Area Groundwater Pumping 127,125 124,089Lateral Flows (Boundary) 15,870 16,098Aquifer outflow to River 3,710 3,093

Method 'C' Accounting Area Groundwater Pumping 30,200 26,100Unaccounted-for difference D 17 1,131,800 574,900

TOTAL WATER ASSET DECREASES 1,308,705 744,280

Total Water Asset Increase 1,743,548 1,434,719Total Water Asset Decrease 1,759,949 1,332,651Total Water Liability Increase 27,022 81,093Total Water Liability Decrease 16,501 12,962




Namoi catchment Statement of Physical Flows Water year ending 30 June 2010 (1 of 2)

SURFACE WATER

Water in Storage Accuracy Notes 30 June 2010 30 June 2009Split Rock Dam A 1 13,685 21,237Keepit Dam A 1 120,480 156,050Gunidgera Weir A 1 1,214 1,489Mollee Weir A 1 98 700River A 2

Upper 54 171Lower 234 3,444



Inflows

Split Rock Dam Inflow A 5 3,857 6,952Gauged Inflow A 6

Upper Namoi 43,895 163,423Lower Namoi

Inflow from Peel (Carroll Gap) 50,469 225,676Other Gauges 115,070 106,210

Ungauged Inflow C 7 Upper Namoi 8,600 32,000Lower Namoi 189,940 119,000

Inflow from Aquifer D 8 3,710 3,093Rainfall

Split Rock B 10 1,077 2,553Keepit B 10 7,724 12,005River (Upper) C 11 1,051 1,611River (Lower) C 11 12,951 9,976


Outflows

Extractions

Upper Namoi A 18 General Security 3,832 0High Security 29 13Local Water Utility 14 3,095Domestic and Stock 6 8Basic Rights Extraction 160 160

Lower Namoi A 18 General Security 28,864 29,682High Security 116 126High Security (Research) 60 100Local Water Utility 847 770Domestic and Stock 658 873Supplementary 39,786 62,860Uncontrolled Flow 0 0Basic Rights Extraction C 15 1,776 1,776

Total Extractions 76,148 94,411

Flow Leaving End of System Flow A 12 264,739 115,073

Losses

Evaporation Split Rock B 10 4,732 5,613Keepit B 10 29,742 27,486River (Split Rock to Keepit) C 11 3,631 3,355River (Keepit to End of System) C 11 24,065 26,283

River outflow to Aquifer D 8 54,950 58,587

Total Outflows 458,007 245,938

Unaccounted-for difference 27,663 287,178

NET INFLOW (47,326)



Namoi catchment Statement of Physical Flows Water year ending 30 June 2010 (2 of 2)

GROUNDWATER Accuracy Notes 30 June 2010 30 June 2009 Water in Storage D 3

Upper Namoi (Method 'A' Area) 201,458 188,459Lower Namoi (Method 'A" Area) 191,200 207,700


CHANGE OF WATER IN STORAGE (3,501) Inflows D 8 Method 'A' Accounting Area

Aquifer Inflow from River 54,950 58,587Lateral Flows 14,730 14,747Recharge

Irrigation 27,241 26,641Rain 46,283 51,245

Method 'C' Accounting Area Recharge 1,162,000 601,000

Total Inflow 1,305,204 752,220 Outflows D 8 Method 'A' Accounting Area

Aquifer Outflow to River 3,710 3,093Lateral Flows 15,870 16,098Groundwater Pumping 127,125 124,089

Method 'C' Accounting Area Groundwater Pumping 30,200 26,100Unaccounted-for difference D 17 1,131,800 574,900

Total Outflow 1,308,705 NET INFLOW (3,501)



Note disclosures



Reconciliation and future prospect descriptions

This information is included in the note disclosures for this GPWAR according to the following requirement of the water accounting standards defined in ED AWAS 1:

‘The following information shall be disclosed in the notes: a) a reconciliation of the change in water storage presented in the Statement of Physical Water Flows to the change in net water assets presented in the Statement of Changes in Water Assets

and Water Liabilities; b) the items comprising both opening water storage and closing water storage presented in the Statement of Physical Water Flows; and c) a reconciliation of closing water storage presented in the Statement of Physical Water

Flows to total water assets presented in the Statement of Water Assets and Water Liabilities’ (Paragraph 139, ED AWAS 1, WASB, 2010).

Further to this it is required to include information that will assist the user to understand the future

propects of the water report entity by defining the water assets available to settle water liabilities and future commitments within 12 months of the reporting date. This is calculated according to the formula:

SWA = WARP + WAI - WA NA - WL E – FC (All components defined in reconciliation of water assets

available to settle water liabilities and future commitments within 12 months of reporting date).

Peel catchment: Reconciliation of change in net water asset to net change in physical water storage 2010 2009 ML MLCHANGE IN NET SURFACE WATER ASSETS (4,966) 13,486

Non-physical adjustments * Net Change in Allocation Accounts 0 0

0 0 NET CHANGE IN PHYSICAL SURFACE WATER STORAGE (4,966) 13,486

Peel catchment: Reconciliation of closing water storage to total surface water assets

2010 2009 ML MLCLOSING WATER STORAGE Surface Water Storage 61,075 66,041

TOTAL SURFACE WATER ASSETS 61,075 66,041

Notes: All figures can be derived from or found directly in the Water Accounting Statements of the General Purpose Water Accounting Report.



Peel catchment: Water assets available to settle water liabilities and future commitments within 12 months of reporting date (ML) Note (ML)

TOTAL WATER ASSETS AS AT 30 June 2010 (WARP) 61,075

Plus: Water asset increases within 12months of reporting date (WAI)

Minimum Storage Inflow 3,700 (a)

Current Inflow Recession 0 (b)

Minimum Usable downstream inflow (Sep to Mar) 2,700 (c) 6,400

Less: Water assets not available to be accessed and taken or delivered within 12 months of reporting date. (WANA)

Unusable Dungowan Volume 4,250 (d)

Storage Net Evaporation 7,500 (e)

Conveyance Loss 7,700 (f)

Storage Reserve 12,000 (g)

End of System Flows 1,800 (h)

Dead Storage 2,360 1 35,610 Water assets available to be accessed and taken or delivered within 12 months of reporting date. 31,865

Less: Water liabilities and future commitments expected to be settled within 12 months of the reporting date.

Water liabilities expected to be delivered within 12 months of reporting date. (WLE)

Surface Water Carryover 0 4 0

Future commitments expected to be delivered within 12 months of reporting date. (FC)

Indicative Allocations and Basic Rights (i) Towns 11,000 4

Domestic and Stock 177 4 High Security 804 4

Basic Rights 299 15 General Security 18,550 4 30,830 30,830Surplus of available water assets over water liabilities and future commitments expected to be settled within 12 months of the reporting date. (SWA) (j) 1,035

Notes:

(a) The statistical long-term annual minimal inflow sequence to storages.

(b) The volume remaining in the current inflow recession in excess of the long-term minimal inflow.

(c) That proportion of the statistical long-term downstream inflow sequence that can be used to settle liabilities and future commitments.

(d) Once Dungowan Dam volume reaches 50% the entire water requirements for Tamworth shift to Chaffey Dam. Therefore, taking into account other losses on Dungowan it is estimated that of the volume in storage above 50% only 50% is usable.

(e) This is an estimate of the annual impact of the net effect rainfall and evaporation on the storages.

(f) This is the volume of water set aside to account for the losses encountered in the delivery of the water liabilities and future commitments.

(g) The minimum storage level set aside in Chaffey Dam for long-term supply of essential requirements.

(h) This is the minimum flow that is expected to pass Peel River at Carol Gap gauging station in a dry year.

(i) Indicative Allocation represents a proposed starting allocation for each licence category. With the Tamworth maximum annual usage being significantly less than their entitlement, which incorporates potential growth, the figure used here is an estimate of maximum annual used. Domestic and stock and high security licences will receive a potential allocation of 100% with 60% for general security.

(j) Remaining uncommitted water that remains that is set aside for future increases to allocation. In principle all water is committed; however data errors ranges and uncertainties dictate that some small amount of water will remain uncommitted.



Namoi catchment: Reconciliation of change in net water asset to net change in physical water storage 2010 2009 ML MLCHANGE IN NET SURFACE WATER ASSETS (23,421) 25,997

Non-physical adjustments Net Change in Allocation Accounts (23,905) 33,509

(23,905) 33,509 NET CHANGE IN PHYSICAL SURFACE WATER STORAGE (47,326) 59,506

Namoi catchment: Reconciliation of closing water storage to total surface water assets

2010 2009 ML MLCLOSING WATER STORAGE Surface Water Storage 135,765 183,091

TOTAL SURFACE WATER ASSETS 135,765 183,091

Notes: All figures can be derived from or found directly in the Water Accounting Statements of the General Purpose Water Accounting Report.




Namoi catchment: Water assets available to settle water liabilities and future commitments within 12 months of reporting date

(ML) Note (ML)

TOTAL WATER ASSETS AS AT 30 June 2010 (WARP) 135,765

Plus: Water asset increases within 12months of reporting date (WAI)

Minimum Storage Inflow 15,400 (a) 15,400

Less: Water assets not available to be accessed and taken or delivered within 12 months of reporting date. (WANA)

Storage Net Evaporation 19,300 (b)

Conveyance Loss 9,800 (c)

Future Commitments Conveyance Loss 2010-11 14,100 (d)

Essential Requirements 2011-12 32,400 (e)

End of System Flows 5,000 (f)

Minimum Storage Release 8,000 (g)

Dead Storage 10,140 1 98,740 Water assets available to be accessed and taken or delivered within 12 months of reporting date.

52,425

Less: Water liabilities and future commitments expected to be settled within 12 months of the reporting date.

Water liabilities expected to be delivered within 12 months of reporting date. (WLE)

Surface Water Carryover 38,282 4 38,282

Future commitments expected to be delivered within 12 months of reporting date. (FC)

Indicative Allocations and Basic Rights (h)

Towns 2,421 4 Domestic and Stock 2,111 4

High Security 3,984 4 Replenishment 14,000 (i)

Basic Rights 1,936 15 24,452

62,734Surplus of available water assets over water liabilities and future commitments expected to be settled within 12 months of the reporting date. (SWA) (j) (10,309)

Notes: (a) The statistical long-term annual minimal inflow sequence to storages. (b) This is an estimate of the annual impact of the net effect rainfall and evaporation on the storages. (c) This is the volume of water set aside to account for the losses encountered in the delivery of the water liabilities and future commitments. (d) This is an allowance for loss set for those periods outside general irrigation releases when essential requirements are required to be supplied. It is assumed that basic rights will be delivered as part of this loss hence a reduction by a volume equivalent to basic rights (16,000 to 14,100 ML). (e) The Namoi catchment puts aside sufficient amount water asset to meet the essential requirements for two years. This figure represents the essential requirement in year two being made up of Towns, high security, stock and domestic, minimum storage releases, basic rights and estimated loss to deliver them. (f) End of system flows are made up of those minimum end of system flows as provided for in the water sharing plan (see Note 12) plus an estimated 3,000 ML of conveyance loss for there delivery. (g) This is the minimum storage release. (h) Indicative Allocation represents a starting allocation 100% for towns, domestic and stock and high security licences. (i) Water set aside under the water sharing plan for up to two replenishment events down Pian Creek to Dundee Weir. (j) Represents a shortfall in 'Essential Requirements 2011-12' to be made up from first available resource.


Note 1 – Surface water storage

This is the actual volume of water stored in the individual surface water storages at the date of reporting. The volumes provided represent the total volume of water in the storage, including dead storage which is the volume of water which can’t be accessed under normal operating conditions e.g.

volume below low level outlet. It is assumed that the dead storage can be accessed if required via alternative access methods e.g. syphons.

Data type Derived from measured data.

Policy Not applicable.

Data accuracy Estimated in the range +/- 10%.

Providing agency NSW Office of Water, Tamworth Regional Council (Dungowan).

Data source NSW Office of Water – HYDSTRA, Tamworth Regional Council.

Methodology Storage volumes excluding Dungowan storage were calculated within HYDSTRA by processing a gauged storage elevation through a rating table that converts it to a volume. For Dungowan storage a

spreadsheet was provided by Tamworth Regional Council containing percentage full information. These figures were multiplied by the storage capacity of 6,300 ML to obtain a volume in storage. The following table provides a breakdown of the storage capacities and dead storages.

Namoi/Peel dam capacity and dead storage

Name Capacity (ML) Dead storage (ML)

Chaffey 61,830 2,360

Dungowan 6,300 300

Keepit 425,510 6,550

Split Rock 397,370 3,160

Gunidgera Weir 1,900 375

Mollee Weir 3,250 50

Total 896,160 12,795



Note 2 – River channel storage

Volume of water stored in the river channel on the day of reporting.



Data accuracy Error range: +/- 50%.

Providing agency NSW Office of Water.

Data sources NSW Office of Water: HYDSTRA, CAIRO.

Methodology For each river section S(n):

V = Q x T

The River Channel Storage will be equal to the sum of all river section volumes:

River Channel Storage = S(n) V

Components of river channel storage volume calculation

Symbol Variable Data Source Unit

Q Average flow in the river section. Calculated by averaging the daily flows at the upstream and downstream river gauges.

HYDSTRA ML/day

V Volume in each river section. Calculated ML

T Average travel time for a parcel of water to travel through the river section.

CAIRO days

Assumptions and approximations • Travel times are estimated to the nearest day.

• Daily flow change between gauging sites assumed to be linear.



Note 3 – Groundwater storage

For the Namoi, this is the volume of ‘accounted’ storage in the groundwater aquifer for zones 2, 3, 4, 5, 11 and 12 of the Upper Namoi groundwater management unit (GMU) and, the Lower Namoi GMU (i.e. the areas that have used groundwater accounting Method A). For the Peel this is the volume of

‘accounted’ storage for the Peel Alluvium (groundwater accounting Method B area)

All areas that use groundwater accounting Method C have been treated as a steady state system, and have no accounted volume. More information on the groundwater methodologies utilised in this

GPWAR is available in Note 8.

Data type Estimate.




Data source NSW Office of Water.

Methodology Accounting under the ED AWAS 1 implies that the groundwater storage volume should be initially determined. As the accounts are a rolling, annual update once an initially storage is defined, annual updates will display the change in storage relative to this starting point. The ED AWAS 1 also indicates

that the volume chosen should represent the ‘extractable portion of the aquifer’. For the purposes of this GPWAR it has been assumed that the opening volume of each aquifer is equivalent to twice the licensed entitlement in the aquifer.

The following table illustrates the annual change in storage from this point in time.

Groundwater change in storage from defined starting volume

Year Upper Namoi Change Lower Namoi Change Peel

Alluvium Change

30-06-2006 204,000*

30-06-2007 169,612 (34,388)

30-06-2008 172,219 (34,388) 216,000*

40,000*

30-06-2009 188,459 2,607 207,700 (8,300) 44,660 4,660

30-06-2010 191,458 16,240 201,458 (6,242) 40,940 (3,720)

Cumulative change

2,999

(14,542)

940

* Twice licensed entitlement (ML)



Additional information Monitoring bore levels for selected locations within the Lower Namoi GMU, the Upper Namoi GMU and the Peel Alluvium. The observed data indicates that for the periods outlined in the above table,

levels are trending upward in the western and central area of the Lower Namoi GMU and downward in the eastern end of the GMU. The selected bores in the Upper Namoi GMU show a falling trend at two locations and a steady trend at the GW036496 (however variation within the period is high). In the

Peel Alluvium the bores indicate that while variation is high for the presented period (July 2008 to June 2010), levels remain relatively constant. This is indicative of a highly connected system and is also supported of the modelling work presented in this GPWAR.

Upper and Lower Namoi Alluvium selected monitoring bores

Peel Alluvium selected monitoring bores

Bore Observations (GW036387)

120

120.2

120.4

120.6

120.8

121

121.2

121.4

121.6

Jun

/200

6

Sep

/200

6

De

c/2

006

Ma

r/2

007

Ju

l/2

007

Oct

/200

7

Jan

/200

8

Ma

y/2

008

Au

g/2

00

8

No

v/2

008

Feb

/200

9

Jun

/200

9

Sep

/200

9

De

c/2

009

Ap

r/20

10

m (

AH

D)



Bore observations (GW036251)

127.35

127.4

127.45

127.5

127.55

127.6

127.65

127.7

Jun

/200

6

Sep

/200

6

Dec

/200

6

Ap

r/20

07

Jul/

2007

Oct

/200

7

Feb

/200

8

May

/200

8

Au

g/2

008

No

v/20

08

Mar

/200

9

Jun

/200

9

Sep

/200

9

Jan

/201

0

Ap

r/20

10

m (

AH

D)


133.6

133.7

133.8

133.9

134

134.1

134.2

Jun

/200

6

Sep

/200

6

Dec

/200

6

Ap

r/20

07

Jul/

2007

Oct

/200

7

Feb

/200

8

May

/200

8

Au

g/2

008

No

v/20

08

Mar

/200

9

Jun

/200

9

Sep

/200

9

Jan

/201

0

Ap

r/20

10

m (

AH

D)


225

225.5

226

226.5

227

227.5

228

Ju

n/2

006

Se

p/2

006

Dec

/20

06

Ap

r/2

007

Ju

l/2

007

Oc

t/2

007

Fe

b/2

008

Ma

y/2

008

Au

g/2

008

No

v/2

008

Ma

r/2

009

Ju

n/2

009

Se

p/2

009

Ja

n/2

010

Ap

r/2

010

m (

AH

D)




250.9

251

251.1

251.2

251.3

251.4

251.5

251.6

251.7

251.8

251.9

Au

g-0

6

Oct

-06

Dec

-06

Feb

-07

Ap

r-07

Jun

-07

Au

g-0

7

Oct

-07

Dec

-07

Feb

-08

Ap

r-08

Jun

-08

Au

g-0

8

Oct

-08

Dec

-08

Feb

-09

Ap

r-09

Jun

-09

Au

g-0

9

Oct

-09

Dec

-09

Feb

-10

Ap

r-10

m (

AH

D)


245

245.1

245.2

245.3

245.4

245.5

245.6

245.7

245.8

Jun

/200

6

Sep

/200

6

Dec

/200

6

Ap

r/20

07

Jul/

200

7

Oct

/200

7

Feb

/200

8

May

/20

08

Au

g/2

008

No

v/20

08

Mar

/200

9

Jun

/200

9

Sep

/200

9

Jan

/201

0

Ap

r/20

10

m (

AH

D)

Bore Observations (GW093024)

481.50

482.00

482.50

483.00

483.50

484.00

Jul/

2008

Au

g/2

008

Sep

/200

8

Oct

/200

8

No

v/20

08

Dec

/200

8

Jan

/200

9

Feb

/200

9

Mar

/200

9

Ap

r/20

09

May

/200

9

Jun

/200

9

Jul/

2009

Au

g/2

009

Sep

/200

9

Oct

/200

9

No

v/20

09

Dec

/200

9

Jan

/201

0

Feb

/201

0

Mar

/201

0

Ap

r/20

10

May

/201

0

Jun

/201

0

m (

AH

D)




366.20

366.40

366.60

366.80

367.00

367.20

367.40

367.60

Jul/

200

8

Au

g/2

008

Sep

/200

8

Oct

/200

8

No

v/20

08

Dec

/200

8

Jan

/200

9

Feb

/200

9

Mar

/20

09

Ap

r/20

09

May

/200

9

Jun

/200

9

Jul/

200

9

Au

g/2

009

Sep

/200

9

Oct

/200

9

No

v/20

09

Dec

/200

9

Jan

/201

0

Feb

/201

0

Mar

/20

10

Ap

r/20

10

May

/201

0

Jun

/201

0

m (

AH

D)



Note 4 – Allocation accounts

These represent the volume of water that is in the licence allocation accounts at the time of reporting. It is the volume of water that is yet to be extracted from the accounts. The balance in accounts at the end of the water year, being a net balance for the licence category, represents that water that is

carried forward to the next water year and is assessed by implementing applicable carryover rules. Carryover rules are applicable to a licence category and will determine whether water can or cannot carryover to the next year, as well as restrictions that may limit the volume of carryover that is

permitted. A negative number indicates that debits to the account have exceeded the available account water, and the deficit must be carried over to the next season.

Water that is in accounts at the end of a water year but is not permitted to be carried over is forfeited

and has been represented as a decrease in the water liability.


Policy Water Sharing Plan for the Upper and Lower Regulated Namoi River Water Sources. Available on NSW Office of Water website at www.water.nsw.gov.au.

Water Act 1912.



Data source State Water/NSW Office of Water – Water Accounting System (Joint ownership of system).

Methodology This figure is the sum of the remaining volume of water in individual allocation accounts at the

conclusion of the water year once all transactions and forfeit rules have been applied to the accounts. These balances are at the licence category level and represent the water that can be carried forward for use in the next year. Below is list of typical transactions that can apply to an allocation account:

• AWD (including pro rata of AWD for new licences)

• licensed extractions

• forfeiture due to

o carryover rules

o account spillage as a result of AWD

o licence conversions

o excess orders (where water order debiting is in place)

• licence conversion

• trade of allocation water between accounts

• transfers

• movement of water to/from drought sub account

• re-crediting of return flows.




Additional information The following tables provide a balanced summary of the water allocation accounts for each water

source broken down into licence category. Below is a table that provides a description of each of the table components.

Components of water allocation account summary tables

Heading Description

Share This is the total volume of entitlement in the specific licence category.

Opening The volume of water that has been carried forward from previous years allocation account.

AWD The total annual volume of water added to the allocation account as a result of allocation assessments.

New Increased in account water as a result of the issuing of a new access licence.

Licences

Cancelled Decrease in account water as a result of a licence cancellation.

In Increase in account water as a result of temporary trade in. Assignments

Out Decrease in account water as a result of temporary trade out.

Accountable Volume of water that is extracted or diverted from the river under controlled river conditions and is accountable against the licence.

Not accountable Volume of water that is extracted or diverted from the river that is not accountable against the licence. In the Namoi this is specific to General Security licences in the Upper Namoi whereby the water sharing plan includes a right to extract water from uncontrolled events once a range of triggers have been met, and the Peel where off allocation events were made available to licence holders.

Extractions

Over order debit Volume of water ordered that exceeding the recorded usage that must also be accountable against the licence.

Available balance Account balance that is available to be taken at the conclusion of the water year.

End of year forfeit Account water that is forfeited at the end of the water year as a result of carryover rules that restrict the carry forward volume.

Carry forward This represents the account water that is permitted to be carried forward into the next water year as determined by the carryover rules.


Upper Namoi account summary

Upper Namoi Regulated Account Summary Data 2009-10

Assignments Extractions Balance

Licence Category

Share 30-06-10

Opening AWD

In Out Accountable Not

Accountable

During Year

Forfeit Available

Non Available

Forfeit End of Year

Carry Forward

Domestic And Stock 76 0 76 0 0 0 0 76 0 76 0

Domestic And Stock [Domestic] 11 0 11 0 0 1 0 10 0 10 0

Domestic And Stock [Stock] 5 0 5 0 0 5 0 0 0 0 0

Local Water Utility 150 0 150 0 0 14 0 136 0 136 0

Regulated River (General Security) 9,724 1,150 4,862 1,021 653 3,832 0 0 2,547 0 313 2,234

Regulated River (High Security) 80 0 80 0 0 29 0 51 0 51 0

Lower Namoi account summary

Lower Namoi Regulated Account

Summary Data 2009-10 Assignments Extractions Balance

Licence Category

Share 30-06-10

Opening AWD Licence

cancelled

In Out Accountable Over Order

Debit

During Year

Forfeit Available

Non Available

Forfeit End of Year

Carry Forward

Domestic And Stock 1,745 (1) 1,745 0 0 0 589 25 8 1,122 0 1,122 0

Domestic And Stock [Domestic] 17 0 20 3 0 0 4 0 0 13 0 13 0

Domestic And Stock [Stock] 257 (0) 257 0 0 0 65 0 0 192 0 192 0

Local Water Utility 2,271 0 2,271 0 0 0 847 0 0 1,424 0 1,424 0


245,222 61,038 1,418 0 11,177 7,946 28,864 558 105 35,251 909 113 36,048

Regulated River (High Security) 3,418 0 3,418 0 25 3,198 116 1 3 125 0 125 0

Regulated River (High Security) [Research]

486 0 486 0 0 426 60 0 0 0 0 0 0

Supplementary Water 115,469 0 115,469 0 451 451 39,786 0 0 75,683 0 75,683 0




Peel account summary

Peel Regulated Account Summary Data 2009-10

Assignments Take Balance

Licence Category

Share 30-06-10

Opening AWD

In Out Accountable Not

Accountable Available

Non Available

Forfeit End of Year

Carry Forward

Domestic And Stock 85 0 85 0 0 39 46 0 46 0

Domestic And Stock [Stock] 20 0 20 0 0 20 0 0 0 0

Domestic And Stock [Domestic] 72 0 72 0 0 40 32 0 32 0

Regulated River (General Security) 30,911 0 30,911 159 159 5,818 25,093 0 25,093 0

Regulated River (High Security) 801 0 801 0 0 119 682 0 682 0

Regulated River (High Security) [Research]

3 0 3 0 0 0 3 0 3 0

Local Water Utility 16,400 0 16,400 0 0 6,676 9,724 0 9,724 0

Off Allocation 4,845


Note 5 – Storage inflow

Storage inflow refers to the volume of water flowing into the major headwater storages.





Data sources NSW Office of Water: HYDSTRA, Tamworth Regional Council spreadsheet, Integrated Quantity and Quality Model (IQQM).

Methodology In most of the major storages in NSW there is no direct measurement of inflows. However, it is possible to calculate inflows by using a mass balance approach (based on balancing the change in

storage volume) where inflow is the only unknown. This is referred to a backcalculation of inflows.

With the exception of Dungowan storage inflow (which used a basic annual approach), the backcalculation figures were derived using a one day time step with the inflow calculated according to

the equation below. The daily inflows are then summed to provide an annual inflow figure:

I = ΔS + O + Se + ((E – R)* Kp* A)

Variables for back calculation of inflow of runoff

Symbol Variable Unit

I Inflow ML/day ΔS Change in storage volume ML O Outflow ML/day Se Seepage ML/day R Rainfall mm/day E Evaporation mm/day Kp Pan evaporation factor A Surface area – derived from height to surface areas lookup curve ha

Assumptions and approximations • Constant storage specific pan evaporation factors are applied.

• Seepage was assumed to be zero.

• Evaporation and rainfall for Dungowan storage was derived from the simulated net evaporation for the storage in the Peel IQQM.



Note 6 – Gauged inflow

The inflow into the regulated river that occurs downstream of the headwater storages that is measured at known gauging stations.


Data type Measured data.



Data sources NSW Office of Water: HYDSTRA.

Methodology The flows are obtained by measuring river heights at gauging stations along the river, and then passing these heights through a rating table that converts them to a daily flow volume.

Additional information The total gauged inflow for 2009-10 is the sum of the inflows for the gauged tributaries defined in the table below.

Summary of gauged inflow, 1 July 2009 to 30 June 2010

Peel Total (ML)

419093 Goonoo Goonoo Creek at Meadows Lane 419016 Cockburn River at Mulla Crossing

73,033

Upper Namoi

419020/419022 Manilla River at Brabri / Namoi River at Manilla Railway Bridge (difference taken as inflow)

43,895

Lower Namoi

419006 Peel River at Carrol Gap

419084 Mooki River at Ruvigne

419032 Coxs Creek at Boggabri

419083 Brigalow Creek at Tharlane

419051 Maules Creek at Avoca East

165,539



Note 7 – Ungauged inflow

The inflow into the river that occurs downstream of the headwater storages that is not measured.


Data type Estimated.



Data sources NSW Office of Water: HYDSTRA, CAIRO.

Qld Department of Natural Resources – SILO.

Methodology Estimating ungauged tributary contributions utilised two separate estimation methods.

The first method is appropriate where ungauged sub-catchment characteristics and rainfall extent are believed to be similar to that of nearby gauged sub-catchments. Gauged tributary inflows are used as a basis for proportioning on area and rainfall distribution across the catchment as defined by the

following steps:

• derive the ratio of gauged to ungauged area by summing gauged area and calculating the ungauged area as the total catchment area less the gauged catchment area

• derive a ratio of annual rainfall volume of the gauged catchment area compared to that of the ungauged area (RF)

• the ungauged inflow is then calculated using the following equation

Ungauged Inflow (ML/yr) = Ungauged Area (Ha)/Gauged Area (Ha) x RF x Gauged Inflow (ML/yr)

In many areas of the catchment, however, such as the low lying areas of the Pillaga region south of

Narrabri, it is evident that gauged catchment factoring will produce a poor estimate of the actual inflow. In these areas, where high runoff events from localised storm events are common it was necessary to utilise the ‘unaccounted-for difference’ from the operations spreadsheet CAIRO. This spreadsheet,

models the system using a reach to reach layout, with a mass-balance calculation of all known parameters as shown below:

UD = FLower – FUpper + FEff + E - I

Where

UD = unaccounted-for difference, FLower = observed flow at lower gauging station, FLower = observed flow at upper gauging station, FEff = effluent outflow, E = extractions, I = Gauged Inflows

The results from each of these methods are then totalled to produce the estimate of ungauged inflow for the full accounting area. Note, in this method it is assumed there is no groundwater interaction.



Note 8 – Ground water balance methodologies

This note is applicable to all parameters presented in the groundwater balance of the accounts.

Data type Modelled, estimated.




Data sources NSW Office of Water: HYDSTRA, GDS.

Qld Department of Natural Resources: SILO.

Commonwealth Bureau of Meteorology: AWAP.

NSW Department Environment Climate Change and Water: Soil Profiles.

Methodology In order to provide a greater coverage of groundwater data in the water accounts it was necessary for the NSW Office of Water to develop and apply various methodologies.

For each groundwater management unit a method was selected according to the following decision

tree:

Groundwater methodology decision tree



The following map gives the methodologies adopted for the different areas of the Namoi and Peel catchments. As can be seen the Lower Namoi GMU and most of the Upper Namoi GMU utilises Method A. In the Peel Alluvium, where there is no groundwater model, yet reasonable coverage of

monitoring bore data available Method B was used. For all other areas, monitoring bore data was insufficient and the only option was to use Method C to derive estimates.

Groundwater methodologies utilised for 2009-10

Method A (MODFLOW)

Description The groundwater models of the Namoi are based on enhancements of earlier models developed by

NSW Office of Water and were developed under a 'MODFLOW96' framework. MODFLOW is a three-dimensional finite-difference groundwater flow model that was developed by the United States Geological Survey (USGS) and is the most widely used program in the world for simulating ground-

water. It has a modular structure that allows it to be easily modified to adapt the code for a particular application.

MODFLOW is used to simulate steady and non steady flow in an irregularly shaped flow system in

which aquifer layers can be confined, unconfined, or a combination of confined and unconfined. Flow from external stresses, such as flow to wells, areal recharge, evapotranspiration, flow to drains, and flow through river beds, can be simulated.

The hydrological stresses accommodated by the model are rainfall, groundwater pumping including that for irrigation, surface water diversions, interaction between the shallow groundwater system and the river system and evapotranspiration.



Account outputs • Lateral flow.

• Recharge (rainfall and river).

• Aquifer inflow from river.

• Aquifer outflow to river.

• Evapotranspiration – from top layer of aquifer.

• Usage is an input to the model using data from the water accounting system. This figure was extracted from the model and used in the accounting.

Method B (Water table fluctuation)

Description The water table fluctuation method is based on the premise that the rises in groundwater levels in unconfined aquifers are due to recharge water arriving at the water table and links the change in

groundwater storage (∆S) with the resulting water table fluctuations (∆h):

hSS y Δ=Δ (1)

Where:

Sy is specific yield of the aquifer

Δh is the change in groundwater levels

The employed methodology is based on applying the water table fluctuation (WTF) method in conjunction with the groundwater water budget method to jointly estimate specific yield and natural

recharge in an unconfined aquifer with significant seasonal water table fluctuations. The water budget method focuses on the various components contributing to groundwater flow and groundwater storage changes (illustrated in the following figure) and can be written as:

SQQPGETQQRFR bfoffriveron Δ++++=+++ (2)

Where:

R is direct recharge from rainfall

RF is irrigation return flow

Qon and Qoff are lateral groundwater flow onto and off the groundwater system

Qriver is river seepage recharge

ET is evapotranspiration

PG is abstraction of groundwater by pumping

Qbf is baseflow (groundwater discharge to streams or springs)

∆S is change in groundwater storage.




Schematic diagram showing the flow components of the groundwater budget

Combining equation (1) with equation (2), we obtain:

hSQQPGETQQRFR ybfoffriveron Δ++++=+++ (3)

By applying equation (3) separately to the dry season, during which R=0, and the wet season, we obtain two equations where the specific yield and natural recharge are the only two unknown parameters:

dryy

drybf

dryoff

drydrydryriver

dryon

dry hSQQPGETQQRF Δ++++=++ (4)

wety

wetbf

wetoff

wetwetwetriver

weton

wet hSQQPGETQQRFR Δ++++=+++ (5)

With the exception of the specific yield and natural recharge, all other seasonal parameters in equation (4) and (5) are either known or can somehow be estimated.

Using equations (4) and (5), the average specific yield and the natural recharge of the aquifer can be estimated as follows:

( ) ( )dry

dryoff

drybf

drydrydryon

dryriver

dry

y h

QQETPGQQRFS

Δ+++−++

= (6)

)()( wetriver

weton

wetwety

wetbf

wetoff

wetwet QQRFhSQQPGETR ++−Δ++++= (7)

Account outputs • Aquifer loss to river.

• Aquifer gain from river.

• Pumping.

• Recharge (irrigation and rainfall).

• Evapotranspiration.

• Seepage.


Method C (Soil water budget)

Description The soil water budget (SWB) method analyses the movement of water among various components of

the hydrologic system using a daily accounting procedure. The method is based on work originally presented by Thornthwaite (1948) and Thornthwaite and Mather (1955 and 1957) and essentially is a book keeping technique that tracks the balance between the inflow of water from precipitation and the

outflow of water by evapotranspiration, stream flow and drainage (potential groundwater recharge).

The SWB method can be defined by the following equation:

P = ET + RO + ∆SW + D (1)

Where:

P is precipitation

RO is surface runoff

ET is evapotranspiration

D is drainage below the root zone of the plants

∆SW is change in soil water over the time step.

The SWB method used in the accounts is a modified version of the above whereby the potential recharge to groundwater is also estimated (based on Scozzavafa and Tallini, 2001). The method uses

the Soil Conservation Service (US) curve number (SCS-CN) method to remove the runoff component from the rainfall before it is applied to the soil water budget analysis. Therefore, any surplus generated from soil water analysis will be taken as a net infiltration (drainage), which in turn is a potential

recharge to the underlying aquifer.

Account outputs Recharge

Additional information Pumping estimates provided in the accounts for the areas utilising Method C were obtained by assuming a usage of 1 ML for each licensed bore.



Distribution of Peel Alluvium balance (GL)

Peel Fractured Rock runoff (GL)



Note 9 – Internal trading

This represents the temporary trading (allocation assignments) of water between allocation accounts within the Regulated Namoi and Peel Rivers.

Data type Administration.

Policy Water Sharing Plan for the Upper Namoi and Lower Namoi Regulated River.

• Part 10 Access licence dealing rules.

o Clause 51 rules relating to constraints within a water source.

Available on the NSW Office of Water Website at www.water.nsw.gov.au.

Water Act 1912 (Peel)




Water Ordering and Usage database.

Methodology Trading is permitted between certain categories of access licences and between certain water sources within the Regulated Namoi and Peel Rivers. This is detailed in the water sharing plan or stipulated under the licence holder’s conditions. Currently no trading is permitted between the Namoi and Peel

systems.

It should be noted that supplementary licence trade has been included in the accounts as no liability was created for this licence category. The net internal trade for other licence categories is zero for a

water year. As such, trades occur as both a water liability decrease (sellers of water) and a water liability increase (buyers of water).



Additional information

Internal trading figures between licence categories

TRADE TO

Lower Namoi

Upper Namoi

Peel

License

Category GeneralSecurity

High Security

Supplementary(1) General Security

GeneralSecurity

TotalTradeFrom

General Security

7,526 420 7,946

High Security

3,173 25 3,198

High Security Research

426 426Lower Namoi

Supplementary (1)

451 451

Upper Namoi General Security

53 601 653

Peel General Security

159 159

TR

AD

E F

RO

M

Total Transferred To 11,177 25 451 1,021 159 12,832

(1) Supplementary Water Access Licences do not create a liability as it is event based and therefore only the extracted water is

included in the accounts. As such trade in supplementary water is not included in the accounts as it has no impact on the

liabilities.



Note 10 – Storage evaporation and storage rainfall

This refers to the volume of water effective on Split Rock, Keepit, Chaffey and Dungowan storages that is either lost as a result of evaporation, or gained as a result of rainfall.





Data source NSW Office of Water – HYDSTRA, Peel Integrated Quantity and Quality Model (IQQM).

Methodology Split Rock, Keepit, Chaffey. The volume applied for evaporation and rainfall on these storages is achieved by first calculating a

daily time-series of storage surface area using a height to area lookup curve as defined in HYDSTRA.

Daily rainfall and evaporation data is then applied to the area time-series to achieve a volume in ML which is then aggregated to an annual figure. The rainfall and evaporation data utilised is equivalent to

the data used in the storage inflow backcalculations, with the same pan factor applied to the evaporation data (note 6).

Rainfall – Volume (ML) = Rainfall (mm) x Area (m2) x 10-6

Evaporation– Volume (ML) = Pan Evaporation (mm) x Pan Factor x Area (m2) x 10-6

Pan factors utilised for calculation

Dam Pan factor

Split Rock 0.85

Keepit 1.00

Chaffey 1.00



Dungowan As indicated in the storage inflows (Note 1) only limited weekly data was available for producing a mass balance of Dungowan storage. For the evaporation and rainfall component a simulated net

evaporation for the accounting period was obtained from the Peel IQQM. As the ED AWAS 1 indicates that offsetting of water balance components should be avoided (and IQQM does not provide a split for rainfall and evaporation), the net evaporation was then separated according to the rainfall and

evaporation climate data ratio and average storage area from the model (assumes pan factor of 1.0).

A x (E – R) = ENET

Where

A = Average area

E = Annual evaporation in mm from nearby site that is applied in the IQQM

R = Annual rainfall in mm from nearby site that is applied in the IQQM

ENET = Net evaporation for reporting period from IQQM

Calculation for 2009-10:

ENET = 456 ML

R = 817 mm E = 1756 A x (E - R) = 456 A = 456 / (1756 - 817) = 0.486

Therefore:

Evaporation from Dungowan storage = 853 ML

Rainfall on Dungowan storage = 397 ML

Assumptions and approximations

Constant (annual) storage specific pan evaporation factors are applied.



Note 11 – River evaporation and river rainfall

This refers to the volume of water effective on the accounted river reach that is either lost as a result of evaporation, or gained as a result of rainfall.


Policy NA.



Data source

NSW Office of Water: HYDSTRA, ARCGIS.

Qld Department of Natural Resources: SILO.

Methodology The volume applied for evaporation and rainfall on the regulated river is achieved by first calculating a

daily time-series of river area. This is achieved by breaking the river up into reaches and utilising the cross sections recorded at river gauging locations to determine the average width of the river with a given daily flow. River length is then determined between two gauging locations using ARCGIS and as

such an area for each reach can be defined.

Area (m2) = Average W (m) x L (m)

Where W is the daily width determined from the gauging cross sections and L is the length as

determined through ARCGIS analysis.

With daily area determined, various climate stations are then selected based on their proximity to each river reach. Rainfall and evaporation data is then extracted from SILO and applied to the area time-

series to achieve a volume in ML which is then aggregated to an annual figure.

Rainfall – Volume (ML) = Rainfall (mm) x Area (m2) x 10-6

Evaporation – Volume (ML) = ET0 (mm) x Kc x Area (m2) x 10-6

Where = ET0 = reference evapotranspiration from SILO and Kc = crop factor for open water (1.05)



Note 12 – End of system flow

This refers to flow that leaves the entity and does not return to the entity.


Policy An end of system environmental flow provision for the Namoi is specified in the Water Sharing Plan for the Upper and Lower Namoi Regulated Water Sources 2003 (available on the NSW Office of Water website at www.water.nsw.gov.au).

The rule states that in the months of June, July and August, a minimum daily flow which is equivalent to 75 per cent of the natural 95th percentile daily flow for each month, shall be maintained in the

Namoi River at Walgett (streamflow gauging station number 419091).

As a volumetric target this is equivalent to 21, 24 and 17 ML/day respectively. The rule is not applicable when the sum of the water stored in Keepit Dam and Split Rock Dam is less than

120,000 ML.

For 2009-10 there was no environmental end of system target for the Peel.



Data source NSW Office of Water – HYDSTRA.

Methodology Summation of flows at gauging sites measuring the volume of water that leaves the entity. For the Namoi and Peel this is represented by the following gauges:

• Peel River at Carrol Gap

• Namoi River at Walgett

These gauges record the time series of heights which are converted to a volume of water based on a derived ‘height to flow’ relationship (rating table).

Additional information While the total dam volumes exceeded 120,000 ML for all of the key months the June 2010 end of system flows requirements were suspended under agreement with NSW Office of Water and NSW

Department of Climate Change and Water due to the small volume of water available to meet this requirement.

River conditions and storage volumes would have dictated that release rates to meet requirements in

June 2010 would have been such that the total dam storage volume would have quickly fallen below the 120,000 ML.

The following graph provides details of the daily flows in comparisons to the daily flow targets at

Walgett.



Minimum flows at Walgett for 2009-10 against Target (plot limited to 200 ML/d)

Minimum Flow Target - Namoi River at Walgett

0

20

40

60

80

100

120

140

160

180

200

1/07

/200

9

31/0

7/20

09

30/0

8/20

09

29/0

9/20

09

29/1

0/20

09

28/1

1/20

09

28/1

2/20

09

27/0

1/20

10

26/0

2/20

10

28/0

3/20

10

27/0

4/20

10

27/0

5/20

10

26/0

6/20

10

Date

Flo

w (

ML

/d)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Vo

lum

e (M

L)

Target Flow Namoi River at Walget Keepit plus Split Rock Volume

Namoi catchment end of system flow (Namoi River at Walgett)

Namoi River at Walgett

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

1/07

/200

9

31/0

7/20

09

30/0

8/20

09

29/0

9/20

09

29/1

0/20

09

28/1

1/20

09

28/1

2/20

09

27/0

1/20

10

26/0

2/20

10

28/0

3/20

10

27/0

4/20

10

27/0

5/20

10

26/0

6/20

10

Date

Flo

w (

ML

/d)

Flow resulting from Barwon River flood backing up the Namoi.

Walgett flows (see above hydrograph) from 12 March to 12 April 2010 were a result of flood flows in the Barwon River caused by water to flow back up the Namoi to the Walgett gauge. As a result the

flows recorded at Walgett for this period, being 192,726 ML were not included as part of the flows leaving the Namoi River at Walgett.



Peel catchment end of system flow (Peel River at Carrol Gap)

Peel River at Carrol Gap

0

1000

2000

3000

4000

5000

6000

7000

8000

01/0

7/2

009

01/0

8/2

009

01/0

9/2

009

01/1

0/2

009

01/1

1/2

009

01/1

2/2

009

01/0

1/2

010

01/0

2/2

010

01/0

3/2

010

01/0

4/2

010

01/0

5/2

010

01/0

6/2

010

ML

/d

While there is a noticeable runoff event from the Peel in 2009-10 (January 2010), this is an extremely small event for the Peel with some of the largest historical events ranging from 40,000 to over 100,000 ML/day.



Note 13 – Uncontrolled flow/off-allocation

This refers to a specific volume of non debit water, as defined in the water sharing plan for the Upper Namoi and the specified on the licence conditions for the Peel catchment (administered under the Water Act 1912), pumped or diverted from the river for consumptive use by general security licence

holders during periods when the extraction of supplementary water is permitted (accessed by various flow targets). It differs from supplementary water (which occurs in the Lower Namoi), which is a defined licence category with a share component that limits the volume pumped during high flow

events.

Data type Measured data

Policy Water Sharing Plan for the Upper and Lower Namoi Regulated Water Sources.

Available on NSW Office of Water website at www.water.nsw.gov.au.

• Part 8 – Limits to the availability of water.

Division 2 – Available water determinations.

o Clause 39 – Available water determinations for regulated river (general security) access licences (6)

Water Act 1912 (Peel).




NSW Office of Water - Water Ordering and Usage database.

Methodology Uncontrolled flow or off-allocation events are announced to specified areas according to a range of

flow triggers that determine an extractable volume of surplus flow. As these events are extracted through the same pumps as those extracting water under other categories of access licences additional information is required to identify periods and hence volumes of uncontrolled flow

extractions. This is achieved by holders providing notification of intent to pump prior to pumping or diverting water during a declared event and provide meter readings both at the commencement and conclusion of pumping. This enables the uncontrolled flow/off-allocation extraction to be assessed

independent of the other categories of access licences.


http://www.water.nsw.gov.au/Water-Management/Water-sharing/default.aspx


Note 14 – Supplementary extraction

This is the volume of water extracted or diverted under supplementary access licences during announced periods of supplementary water. Supplementary flow events are announced periodically during the season when high flow events occur with the period of extraction and volume of water to be

extracted determined based on the rules as set out in the water sharing plans. It is important to note that supplementary access licences differ from other categories of access licence in that the volume of water in the account refers to an annual upper limit for extractions and its provision is totally reliant on

the occurrence of high flow events. Supplementary access licences existed only in the Lower Namoi for 2009-10.


Policy Water Sharing Plan for the Upper and Lower Regulated River Water Sources.

• Part 8 Limits to the availability of water.

Division 2 – Available water determinations.

o Clause 39 – Available water determinations for supplementary water access licences.

• Part 9 – Rules for managing access licences.

Division 2 – Extraction conditions. o Clause 49 – Taking of water under a supplementary licence in the Lower Namoi

Regulated River Water Source.

Refer to applicable water sharing plan on NSW Office of Water website at www.water.nsw.gov.au.




Methodology Supplementary water extraction and diversion data is collected by either on farm meters that measure extraction or gauges on diversion works. Meter readings are collected for individual licence holders at intervals during the year and converted via a calibration factor to a volume of water extracted. Water

diverted from the river is measured by recording the height at either the gauge or weir with the volume diverted being derived by passing these heights through a rating table. However, with supplementary water being extracted through the same pumps as those extracting water under other categories of

access licences additional information is required to separate out supplementary extraction. Basically licence holders provide notification of their intention to pump prior to pumping or diverting water during the declared supplementary event and provide meter readings both at the commencement and

conclusion of pumping. This enables the supplementary flow extraction to be assessed independent of other categories of access licences.

The total volume of supplementary extractions is then calculated by summing the individual

extractions and diversions that occurred during declared periods of supplementary flow for the water year.



Note 15 – Basic rights

This is water extracted to meet the annual requirements of domestic and stock rights in the water source.

Data Type Estimated

Policy Water Sharing Plan for the Upper and Lower Regulated River Water Sources.

• Part 4– Basic landholder rights.

o Clause 18 – Domestic and stock rights.

Available on the NSW Office of Water website at www.water.nsw.gov.au.



Data source Water Sharing Plan for the Water Sharing Plan for the Upper and Lower Namoi Regulated Water Sources.

Water Sharing Plan for the Peel Valley Regulated, Unregulated, Alluvium and Fractured Rock Water

Sources.

Methodology The estimation of domestic and stock rights uses a series of estimates for water usage, stocking rates,

population and property shape based on local knowledge to calculate riparian (stock and domestic) requirements in ML per year.

The annual extraction for Domestic and Stock Rights in the water accounts is assumed to be the

figure stated in the water sharing plans (note the Peel water sharing plan was not operational for the reporting period however the estimate provided in this plan was used)



Note 16 – Available Water Determination (AWD) (Allocation Announcement)

This is the process by which the regulated surface water asset available for use within the regulated

system is determined and shared. It determines the volume of water that is to be added to an individuals licence allocation account. Announcements of allocations are made on a seasonal basis - usually corresponding with the financial year and are updated on a regular basis or following

significant inflow events. Under the Water Management Act 2000 the announcements are termed available water determinations, while under the Water Act 1912 (Peel) this process is known as an allocation announcement.


Policy

Water Act 1912.

Water Management Act 2000 (NSW).

• Chapter 3 – Part 2 Access Licences.

o Clause 59 – Available water determinations.

Water Sharing Plan for the Upper and Lower Namoi Regulated Water Sources.

Available on the NSW Office of Water website at www.water.nsw.gov.au.

• Part 8 – Limits to the availability of water

o Division 2 – Available water determinations.




Available Water Determination Register - NSW Office of Water website at www.water.nsw.gov.au.

Methodology The AWD procedure itself is generally divided into two sections; the available water asset, and system commitments. The remaining asset once system commitments have been met is then available for

distribution to the categories of access licences in order of priority (see following table). The volume of the announced allocation is expressed as the percentage of share component of the licence.

The Available Water Asset is calculated by summing the water currently available in storage, future

(minimum) inflows to the system, and additional volumes due to recessions of inflows from the current levels to the minimum inflow levels. Also taken into consideration is the reduction of the total inflows to the system for those that arrive too late in the season to be useful.




Priority of Available Water Determinations for each licence category

Licence Category AWD Priority

General Security Low

High Security High

Conveyance Low

Domestic and Stock* Very High

Local Water Utility Very High

Note: Domestic and Stock is further broken down into three sub categories: Domestic and Stock, Domestic and Stock (Domestic) and Domestic and Stock (Stock). For the purposes of this report and the general purpose water account they were all treated as Domestic and Stock.

System Commitments – this is an assessment of the existing commitments that have to be delivered from the Available Water Asset in either the current or future years. Key components include:

• essential supplies include things such as town water supplies, stock and domestic requirements, industrial use and permanent plantings (e.g. orchards, vineyards) and environmental allowances

• undelivered account water is the water that is already in accounts that is yet to be provided

• end of system flow requirement is an estimate of the flow that to pass through the

system as a result of operation of the system

• losses which are estimated as the amount of water that will be lost by the system either through evaporation or in the process of delivering the water via transmission losses.

It should be noted that the AWD for supplementary licence accounts is a separate process and is not dependent on water asset available. It is made once at the start of the year and unless there is a management change due to the growth in use strategy it is maintained at the maximum value

prescribed in the plan generally 100% of share component.

Additional information

The following pages contain the allocation summary reports for 2009-10. Below is a table containing

report notes to help interpret the report.

Allocation Summary Report Notes

Share Component (Entitlement) Sum of the licensed volume of water within the licence category on the announcement date.

Individual Announcement Actual announcement made to each licence category

Announced Volume Volume of water credited to accounts within a licence category as a result of the announcement made.

Cumulative Volume Cumulative total of the announced volumes for the water year and licence category.

Balance Made Available Sum of water available in allocation accounts that has been made available to be taken during the season.

Non Available Balance Water allocated that is not accessible at this point in time.

Percent of Entitlement This is the volume expressed as a percentage of the entitlement applicable on the particular date.

Opening Remaining allocation account balances at the conclusion of the previous season that is allowed to be carried forward to this season.

Supplementary Water Water that is not a stored source of water and is only made available if an uncontrolled flow event occurs.


Upper Namoi announcements summary

Date Individual


Allocation Volume

(ML)

Cumulative Volume

(ML) % of

Entitlement Cumulative

%

Balance Available

(ML)

Non Available

(ML) Total (ML) Available Total

Domestic And Stock

Opening 76 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 76 76 76 100% 100% 76 0 76 100% 100%


Opening 11 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 11 11 11 100% 100% 11 0 11 100% 100%


Opening 5 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 5 5 5 100% 100% 5 0 5 100% 100%

Local Water Utility

Opening 150 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 150 150 150 100% 100% 150 0 150 100% 100%


Opening 9,724 1,150 0 1,150 12% 12%

1-Jul-09 AWD 0.5 ML per Share 9,724 4,862 4,862 50% 50% 6,012 0 6,012 62% 62%


Opening 80 0 0 0 0% 0%

1-Jul-09 AWD 1.0 ML per Share 80 80 80 100% 100% 80 0 80 100% 100%



Lower Namoi announcements summary

Date Individual

Announcement Entitlement Allocation

Volume (ML) Cumulative

Volume (ML) % of

Entitlement Cumulative

%

Balance Available

(ML)

Non Available

(ML) Total (ML) Available Total

Domestic And Stock

Opening 1,745 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 1,745 1,745 1,745 100% 100% 1,744 0 1,744 100% 100%


Opening 20 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 20 20 20 100% 100% 20 0 20 100% 100%


Opening 257 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 257 257 257 100% 100% 257 0 257 100% 100%

Local Water Utility

Opening 2,271 0 0 0 0% 0%

1-Jul-09 AWD 100.0 % 2,271 2,271 2,271 100% 100% 2,271 0 2,271 100% 100%


Opening 246,212 60,134 904 61,038 24% 25%

5-Nov-09 AWD 0.0058 ML per Share 246,212 1,424 1,424 1% 1% 61,530 909 62,439 25% 25%


Opening 3,418 0 0 0 0% 0%



Opening 486 0 0 0 0% 0%

1-Jul-09 AWD 1.0 ML per Share 486 486 486 100% 100% 486 0 486 100% 100%

Supplementary Water

Opening 115,469 0 0 0 0% 0%





Peel announcements summary

Date Individual


Allocation Volume

(ML)

Cumulative Volume

(ML)

% of Entitlement

Cumulative %

Balance Available

(ML)

Non Available

(ML)

Total (ML)

Available Total

Domestic And Stock

Opening 85 0 0 0 0% 0%

1-Jul-09 AWD 100 % 85 85 85 100% 100% 85 0 85 100% 100%


Opening 72 0 0 0 0% 0%

1-Jul-09 AWD 100 % 72 72 72 100% 100% 72 0 72 100% 100%


Opening 20 0 0 0 0% 0%

1-Jul-09 AWD 100 % 20 20 20 100% 100% 20 0 20 100% 100%

Local Water Utility

Opening 16,400 0 0 0 0% 0%

1-Jul-09 AWD 100 % 16,400 16,400 16,400 100% 100% 16,400 0 16,400 100% 100%


Opening 30,911 0 0 0 0% 0%

1-Jul-09 AWD 80% 30,911 24,729 24,729 80% 80% 24,729 0 24,729 80% 80%

10-Nov-09 AWD 100 % 30,911 6,182 30,911 20% 100% 30,911 0 30,911 100% 100%


Opening 801 0 0 0 0% 0%

1-Jul-09 AWD 100 % 801 801 801 100% 100% 801 0 801 100% 100%


Opening 3 0 0 0 0% 0%

1-Jul-09 AWD 100 % 3 3 3 100% 100% 3 0 3 100% 100%


Note 17 – Unaccounted-for difference

In theory if all the processes of a water balance could be accurately accounted for, the unaccounted-for difference would be zero. In reality due to the large uncertainties in many of the volumes presented in the accounts, the various sources from which the data has been obtained and the fact that not all

processes of the water cycle have been accounted, the statements are not balanced at the end of the accounting process. In order to balance the accounts a final balancing entry is required, and this is termed the unaccounted-for difference. As technology progresses and accuracy improves in the

account estimates, it is anticipated that relatively this figure should reduce in future accounts.

Data type Not applicable.



Providing agency Not applicable.

Data source Not applicable.

Methodology For surface water the unaccounted-for difference is equal to the amount required to obtain the correct volume in river at the end of the reporting period, after all the known physical inflows and outflows have been accounted. The double-entry accounting process attempted to represent the physical

movement of water by creating a river asset. The opening and closing balance of the river volume was estimated according to Note 2.

For groundwater areas covered by Method A or B (see note 8) the full balanced output from the

groundwater modelling was used and as such has no unknown component. For areas accounted using Method C a steady state system was assumed with the volume required to maintain this attributed as the unaccounted-for difference. This volume would include losses such as

evapotranspiration, seepage to springs and loss to other groundwater aquifers.

Surface Water Unaccounted-for difference

UVSW = Rs – Rc + RI - Ro

Where: UVSW = unaccounted-for difference for surface water, Rs = opening river volume estimate, Rc = closing river volume

estimate, Ro = physical outflows from the river (e.g. extractions, diversions), RI = physical inflows to the river (e.g. runoff, return

flows, dam releases).

Groundwater unaccounted-for difference (Method C areas)

UVGW = RGW + EGW

Where: UVGW = Unaccounted-for difference for groundwater areas accounted with Method C, RGW = Recharge to groundwater

areas accounted with Method C, EGW = Estimated extraction from groundwater areas accounted with Method C



Note 18 – Extractions

This refers to the actual volume of water either pumped or diverted from the river or aquifer by licensed users. It is broken up by licence category and in some circumstances by water sharing plan rules e.g. for uncontrolled flow.





Data source State Water/NSW Office of Water – Water accounting system (joint ownership of system).

NSW Office of Water – Water ordering and usage database.

Methodology The extraction and diversion data is collected by either on-farm meters that measure extraction or gauges on diversion works. Meter readings are collected for individual licence holders at intervals during the year and converted via a calibration factor to a volume of water extracted. Water diverted

from the river is measured by recording the height at either the gauge or weir with the volume diverted being derived by passing these heights through a rating table. However, with multiple categories of access licences being extracted through the same pumps additional information and methodologies

are required to separate use under the various licence categories. Below is a description of these:

• Based on periods of announcement – during periods of supplementary water announcements extractions can be debited against either the Supplementary Water

Licences or tagged as Uncontrolled Flow.

• Extractions based on water orders – users place orders for water against an access licence and extractions are debited against accounts in proportion to the orders placed.

• Licence Category Apportionment – if no water orders are available water extracted is apportioned against categories of access licence in order of priority as set out in the table below. The prioritising is based on the nature and rules around each of the licence

categories.

The following table provides the order in which extractions are apportioned to access licence categories. In the table following licensed extractions are apportioned in order of priority starting at

priority 1. This is a generic list where not all categories will necessarily appear in this GPWAR. There are also various sub categories of licence associated with some of the categories.



Licence Category Apportionment Table

Priority Surface Water Groundwater

1 Supplementary Domestic and Stock

2 Uncontrolled Flow Supplementary

3 Domestic and Stock Aquifer

4 Regulated River High Security Local Water Utility

5 Regulated River General Security Major Water Utility

6 Conveyance

7 Local Water Utility

8 Major Water Utility



Note 19 – Held environmental water

This represents that environmental water that is held as part of a licensed volumetric entitlement. These licences are held within the same licence categories as all other water access licences hence are subject to the same operating rules. Therefore they are subject to the following key rules:

• Available Water Determinations (AWD) for their share of the entitlement to be added to accounts.

• Intravalley trading is permitted within the licensed category constraints detailed in the

water acts and the water sharing plan. This includes trading of environmental water to non-environmental consumptive use purposes.

• Carryover rules hence the forfeiting of unused water that cannot be carried over.

• Provide water orders prior to use.

Data type Measured

Policy

Water Management Act 2000.

• Dealings with access licences (Division 4).

o 71G Assignment of water allocations between access licences.

Water Sharing Plan for the Upper and Lower Namoi Regulated River Water Sources.

• Part 8 – Limits to the availability of water.

o Division 2 –Available Water Determinations.

• Part 10 – Access licence dealing rules.

o Clause 51 – Rules relating to constraints within a water source.

o Clause 55 – Rules for water allocation assignment between water sources.

o Clause 56 – Rules for interstate assignment of water allocations.

Available on the NSW Office of Water Website at: www.water.nsw.gov.au.




Available Water Determination Register – NSW Office of Water website at www.water.nsw.gov.au.

Methodology The water held for the environment represents a volume of water in corresponding allocation

accounts. This allocation account represents the sum of the remaining volume of held environmental water at the conclusion of the water year once all transactions and forfeit rules have been applied to the accounts. These environmental balances are at the licence category level and represent the water

that can be carried forward for use in the next year. Below is list of typical transactions that can apply to an environmental allocation account:

• AWD (including pro rata of AWD for new licences)




• Licensed extractions

• Forfeiture due to:

• Carryover Rules

• Account spillage as a result of AWD

• Licence conversions

• Excess orders (where water order debiting is in place)

• Licence conversion

• Trade of allocation water between accounts

In addition the trade and purchase of environmental water is tracked to capture the movement of

environmental entitlement both in number of entitlements, and volume.

All of this is more clearly depicted in the table provided on the following page.


Additional Information Namoi Environmental regulated account summary 2009-10

30-06-2009 30-06-2010 Assignments

Licence Category No. lic. Share No. lic. Share

Opening AWD

In Out

Extraction AccountBalance

ForfeitEnd of Year

Carried Forward

Lower Namoi Water Source

Regulated River (General Security) 1 3,728 1 6,098 0 27 53 0 0 79.8 0 79.8

Regulated River (High Security) 1 0 1 0 0 0 0 0 0 0 0

Upper Namoi Water Source

Regulated River (General Security) 1 105 1 105 0 53 0 53 0 0.0 0 0

Regulated River (High Security) 1 0 1 0 0 0 0 0 0 0 0 0

Total Namoi

Regulated River (General Security) 2 3,833 2 6,203 0 80 53 53 0 79.8 0 79.8

Regulated River (High Security) 2 0 2 0 0 0 0 0 0 0 0 0

Trade from Upper Namoi Environmental GS to Lower Namoi Environmental GS 52.5



Note 20 – Water order debiting

Currently in the Lower Namoi the allocation accounts are managed using an over-ordering debiting system. Accounting under this system implies that the accounts are reduced by the greater of:

• the volume of water extracted

• the volume of water ordered for extraction against an access licence.

Therefore the volume appearing in statements against the line item water order debiting reflects the amount of water ordered against a category of licence that is in excess to the physical extraction that

occurred.

Data type Measured/calculated

Policy Water Sharing Plan for the Upper and Lower Namoi Regulated River Water Sources.

• Part 9 – Rules for managing access licences.

• Division 2 – Water allocation account management.

o Clause 43 – Volume taken under access licences.

Available on the NSW Office of Water website at: www.water.nsw.gov.au.




Methodology

Water order debiting is a required component of balancing the allocation accounts detailed in note 4.

The over-order component is calculated by analysing the recorded extractions against orders.



Note 21 – Dungowan pipeline diversion

Tamworth also has a supplementary supply for town water purposes from Dungowan Dam which is owned and operated by Tamworth Regional Council. This water is supplied to town through a 60 km 500 mm diameter pipeline directly to the Calala Water Treatment Plant (Cameron, 2001).

Data type Measured.



Providing agency Tamworth Regional Council.

Data source Excel spreadsheet.

Methodology Weekly figures in ML provided by Tamworth were aggregated to an annual figure. In the accounting

process this is a decrease in asset that does not get transferred to the river asset as the storage releases do.



Namoi catchment

Assurance Statement

An Assurance Statement is required under the ED AWAS 1 for a general purpose water account which states that the accounts were prepared in accordance with the ED AWAS 1. It is a requirement

that this be provided by an appropriately qualified assurance provider independent of the water reporter and it management and governing body.

An assurance framework has yet to be provided under the ED AWAS 1 and in lieu of it the NSW Office

of Water will not be providing an Assurance Statement for the 2009-10 water account.

As an assurance statement was not possible, the NSW Office of Water approached the Water Accounting Standards Board who issued the following statement in regards to this GPWAR:

‘The Water Accounting Standards Board (WASB) acknowledges the completion of a General Purpose Water Accounting Report for the Namoi catchment by the NSW Office of Water. This is a major step in the adoption of standards-based water

accounting and we applaud their exceptional effort in the production of this report and their continued involvement in the development of Australian Water Accounting Standards (AWAS).’




References

BOM 2010, Pilot National Water Account, Bureau of Meteorology

Cameron, Adrian 2009, Well, Well, Well – Drift Well Recommissioning, an Operators Perspective, Tamworth Regional Council, 3rd Annual WIOA NSW Water Industry Engineers & Operators Conference

WASB 2010, Exposure Draft of Australian Water Accounting Standard 1 Preparation and Presentation of General Purpose Water Accounting Reports (ED AWAS 1), Bureau of Meteorology

general purpose water accounting report 2009–2010€¦ · general purpose water accounting report...

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