Water resources and management overview ... - NSW Office of Water

Water resources and management overview Macquarie-Bogan catchment

Leading policy and reform in sustainable water management

Publisher NSW Office of Water Level 18, 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. Water resources and management overview: Macquarie-Bogan catchment March 2011 ISBN 978 1 74263 161 5 This report may be cited as: Green D., Petrovic J., Moss P., Burrell M. (2011) Water resources and management overview: Macquarie-Bogan catchment, NSW Office of Water, Sydney Cover photo: Bogan River at Kamilaroi Highway (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_376

Water resources and management overview: Macquarie-Bogan catchment

Contents 1

Introduction.................................................................................................................................... 1

2

Climate .......................................................................................................................................... 3 2.1

Rainfall ................................................................................................................................ 3

2.2

Evaporation ......................................................................................................................... 4

3

Land use........................................................................................................................................ 5

4

Environment .................................................................................................................................. 7

5

4.1

Native vegetation ................................................................................................................ 7

4.2

Parks and reserves ............................................................................................................. 7

4.3

Wetlands ............................................................................................................................. 8

4.4

Significant biodiversity ........................................................................................................ 9

Surface water .............................................................................................................................. 10 5.1

Macquarie River upstream of Burrendong Dam ............................................................... 10

5.2

Cudgegong River .............................................................................................................. 10

5.3

Burrendong Dam to Narromine......................................................................................... 11

5.4

Bogan River ...................................................................................................................... 11

5.5

Lower Macquarie River ..................................................................................................... 11

5.6

Stream flow characteristics ............................................................................................... 12

6

Groundwater................................................................................................................................ 15

7

River operations and management ............................................................................................. 18 7.1

Major storages and regulating structures ......................................................................... 18

7.2

Irrigation areas .................................................................................................................. 19

7.3

Licensed water use ........................................................................................................... 20

7.4

8

7.3.1

Surface water........................................................................................................ 20

7.3.2

Groundwater ......................................................................................................... 21

Water sharing plans .......................................................................................................... 21 7.4.1

Surface water sharing plan................................................................................... 22

7.4.2

Groundwater sharing plans .................................................................................. 23

7.4.3

Plans in preparation.............................................................................................. 24

References .................................................................................................................................. 25

i | NSW Office of Water, March 2011


Tables Table 1: Land use in the Macquarie-Bogan catchment......................................................................... 5 Table 2: Threatened aquatic species of the Macquarie-Bogan catchment........................................... 9 Table 3: Mean daily flow for selected Macquarie and Bogan River gauges ....................................... 12 Table 4: Major storages in the Macquarie catchment ......................................................................... 18 Table 5: Private irrigation schemes in the Macquarie catchment........................................................ 19 Table 6: Surface water entitlements for the Macquarie-Bogan catchment 2009-10 ........................... 20 Table 7: Groundwater entitlements for the Macquarie-Bogan catchment 2009.................................. 21

Figures Figure 1: The Macquarie-Bogan catchment .......................................................................................... 2 Figure 2: Topography and elevation of the Macquarie-Bogan catchment ............................................ 2 Figure 3: Average annual rainfall in the Macquarie-Bogan catchment ................................................. 3 Figure 4: Mean monthly rainfall at Trangie 1922-2009 ......................................................................... 3 Figure 5: Average annual pan evaporation in the Macquarie-Bogan catchment .................................. 4 Figure 6: Mean daily evaporation at Trangie 1971-2009 ...................................................................... 4 Figure 7: Major land use types in the Macquarie-Bogan catchment..................................................... 6 Figure 8: Annual flow in the Macquarie River at Dubbo 1915-2010 ................................................... 13 Figure 9: Daily flows in the Macquarie River at Dubbo and cumulative deviation from the mean.................................................................................................................................. 14 Figure 10: Groundwater aquifer types of the Macquarie-Bogan catchment ....................................... 15 Figure 11: Groundwater Management Areas of the Macquarie-Bogan catchment............................. 16 Figure 12: Groundwater quality and suitability in the Macquarie-Bogan catchment ........................... 16

ii | NSW Office of Water, March 2011


1 Introduction The Macquarie-Bogan catchment covers an area of more than 74,000 km2 within the Murray-Darling Basin. The headwaters of the Macquarie River originate in the Great Dividing Range south of Bathurst, and the river flows in a north-westerly direction for 960 km until it joins the Barwon River near Brewarrina (Figure 1). The major tributaries of the upper Macquarie catchment are the Cudgegong, Talbragar and Little and Bell Rivers. The Bogan River rises in the Harvey Ranges near Peak Hill and flows roughly parallel to the Macquarie across the north-western plains before joining the Barwon River downstream of Brewarrina. In the lower part of the catchment a series of effluent creeks break away from the Macquarie River, connecting with the Bogan River. Elevations across the catchment range from 1,300 m in the mountains south of Bathurst to less than 100 metres near Brewarrina in the far north of the catchment. Below Dubbo, the valley is predominantly comprised of flat alluvial plains with elevations less than 300 m (Figure 2). Water in the Macquarie River is regulated by two major storages in the upper catchment. Burrendong Dam supplies water for irrigation, stock and domestic needs along the Macquarie River and the lower Bogan River as well as providing significant flood mitigation capability to reduce downstream flooding. It also stores water for environmental requirements in the Macquarie Marshes, an extensive wetland complex that is a significant natural feature of the lower valley. Windamere Dam, on the Cudgegong River upstream of Burrendong Dam, provides water for the towns of Mudgee and Gulgong and water user requirements along the Cudgegong River. The Wiradjuri people were the original inhabitants of the upper and middle catchment. On the downstream plains the Bogan River formed the boundary between the Wongaibon people to the west and the Wailwan people in the east. Today the Macquarie-Bogan catchment supports around 180,000 people. Over half of this population lives within the regional cities of Dubbo, Orange and Bathurst (all with populations of around 30,000 people) or the town of Mudgee (with around 8,200 people). The catchment has a number of smaller towns with populations of 1,000 to 4,000 people including Wellington, Narromine, Nyngan and Warren. The Macquarie-Bogan catchment supports a diverse range of industry including agriculture, agribusiness, tourism, mining and viticulture. The largest agricultural use of water in the valley is for cotton production downstream of Dubbo. Other significant irrigated crops include lucerne, cereals, oilseed, wheat and vegetables. Most of the major cities and towns rely on the rivers in the catchment for their water supply including Bathurst, Orange, and Oberon upstream of Burrendong Dam, and Dubbo, Wellington, and Nyngan on the Macquarie River below Burrendong Dam. Lithgow also receives water for town water supply from the Fish River Scheme. Macquarie River at Oxley upstream of the Macquarie Marshes

1 | NSW Office of Water, March 2011


Figure 1: The Macquarie-Bogan catchment

Figure 2: Topography and elevation of the Macquarie-Bogan catchment



2 Climate 2.1 Rainfall Average annual rainfall in the Macquarie-Bogan catchment ranges from over 1,200 mm in the southeast to around 300 mm in the north-west. Rainfall across most of the lower catchment averages 300500 mm/year (Figure 3). Mean monthly rainfall at Trangie, in the middle of the catchment, shows slight summer dominance, with the highest rainfall occurring between October and March, and the lowest months of rainfall being August and September (Figure 4). Figure 3: Average annual rainfall in the Macquarie-Bogan catchment

Source: Hutchinson and Kesteven 1998

Figure 4: Mean monthly rainfall at Trangie 1922-2009

Source: Bureau of Meteorology Climate Data Online



2.2 Evaporation Pan evaporation in the Macquarie-Bogan catchment has a strong east-west gradient. Average Class A pan evaporation varies from around 900 mm/year in the south-east, to over 2,200 mm/year in the north-west (Figure 5). Pan evaporation is also highly seasonal throughout the year. At Trangie mean daily evaporation ranges from 10 mm in December and January to a low of 2 mm in June and July (Figure 6). Figure 5: Average annual pan evaporation in the Macquarie-Bogan catchment

Source: Hutchinson and Kesteven 1998

Figure 6: Mean daily evaporation at Trangie 1971-2009

Source: Bureau of Meteorology Climate Data Online



3 Land use Land use in the Macquarie-Bogan catchment is dominated by extensive agriculture with over 80 per cent of the catchment being used for grazing. Dryland cropping accounts for 9 per cent of land use, and occurs predominantly in the middle and lower parts of the catchment. Forestry, conservation and other native landscapes together account for about 5 per cent of the catchment area (Table 1, Figure 7). While economically very important, irrigated cropping covers less than 2 per cent of the valley. In the year 2000 approximately 775 km2 were irrigated in the Macquarie valley, with 524 km2 (67 per cent) being for cotton production (CSIRO 2008). Other irrigated crops in order of area planted are wheat and cereals, fodder and pasture, lucerne, oilseeds and vegetables. Grapes for wine production are cultivated in the Orange and Mudgee districts and vegetables are grown on the Macquarie floodplain around Bathurst. Orchards are grown in the upper catchment and in the Narromine-Trangie area with crops including apples, citrus, cherries and stone fruit (MDBC 2007). Table 1: Land use in the Macquarie-Bogan catchment Land use category Grazing

2 Area (km )

Proportion of catchment (%)

61,037

81.6

Dryland cropping and horticulture

6,954

9.3

Native landscapes

1,986

2.7

Forestry

1,841

2.5

Irrigation

1,182

1.6

Conservation

872

1.2

Residential

540

0.7

Wetlands

275

0.4

Lakes, rivers, dams

117

0.2

5