Macquarie-Bogan catchment

Transcription

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
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
<0.1
Mining
Source: 2001/02 Land use mapping of Australia, Bureau of Rural Sciences
Figure 7: Major land use types in the Macquarie-Bogan catchment
Source: 2001/02 Land use mapping of Australia, Bureau of Rural Sciences
4 Environment
4.1 Native vegetation
The Macquarie catchment previously supported a complex mosaic of forests, temperate and semi-arid
woodlands, wetlands, shrublands, heaths and grasslands. Large scale clearing and subsequent
degradation has reduced many of these vegetation communities to isolated remnants on the less
fertile and productive soils. The following overview of the vegetation of the Macquarie catchment is
based on mapping and descriptions by Keith (2004).
In the upper catchment the most common vegetation communities remaining are the dry sclerophyll
forests and grassy woodlands of the Southern Tablelands. The Southern Tablelands dry sclerophyll
forests occur on the dry rocky parts of the Great Dividing Range south from Mudgee and in the hills
surrounding Bathurst and Oberon. The main tree species are red stringybark and scribbly gum. The
Southern Tablelands grassy woodlands occur at elevations above 600 m in the Bathurst and Oberon
areas and are dominated by Blakely’s red gum and apple box with several other associated species.
Around Mudgee these communities give way to the dry sclerophyll woodlands and grassy woodlands
of the western slopes which are both dominated by white box, kurrajong and cypress pine. North of
Dubbo there are large areas of dry sclerophyll forest dominated by box, red gum and ironbarks with a
subcanopy of cypress pine. These forests are a southern extension of the Pilliga scrub community
which have formed on alluvial sediments washed out from the surrounding sandstone ranges. The
lower part of the Macquarie catchment is dominated by riverine and floodplain woodlands with river
red gum along the watercourses and black box dominant on the floodplain.
4.2 Parks and reserves
National parks and reserves protect nearly 1,300 km2 of habitat within the Macquarie-Bogan catchment.
Most of the protected areas are found in the upper catchment, and with the exception of the Macquarie
Marshes Nature Reserve there are few areas managed for conservation in the lower valley.
Turon National Park protects over 30 km2 of open eucalypt forests and river oaks along the Turon
River in the catchment above Burrendong Dam.
Coolah Tops National Park on the Liverpool Range, protects the headwaters of the Talbragar River which
flows to the Macquarie River at Dubbo. The park features scenic lookouts, waterfalls and basalt ranges, and
protects extensive areas of silvertop stringybark and snowgum forest. Other forest types within the park
include mountain ribbon gum, yellow box, and the endangered grassy white box woodland (NPWS 2002).
Goobang National Park near Peak Hill forms an ecological island amongst the heavily cultivated
landscape of the central west. Encompassing the Hervey Range, and rising to elevations of up to
800 metres above the surrounding plains, the park forms part of the catchment divide between the
Macquarie and the Bogan Rivers. Vegetation communities include dry sclerophyll woodlands, grassy
white box woodlands, heathland, and mallee. It supports a number of threatened animal species
including the koala, regent honeyeater, glossy black cockatoo, superb parrot, and turquoise parrot.
The Macquarie Marshes Nature Reserve comprises three parcels of land totalling over 181 km2. The
reserve was gazetted in 1971 on an area of land previously set aside in 1900 for the preservation of
game (NPWS 1993). The reserve protects the core wetland areas that are most frequently flooded, and
contains samples of all the habitat types typical of the marshes. Significant wetland areas are also located
outside the nature reserve on private land, including extensive river red gum woodlands and some of the
largest waterbird rookeries in the marshes. In 2008 the Australian Government purchased the adjacent
property of Pillicawarina which will add an additional 10 per cent to the area and connect the north and
south portions of the nature reserve.
4.3 Wetlands
The Macquarie Marshes are listed as a wetland of international importance under the Ramsar
Convention. The Ramsar site comprises the Macquarie Marshes Nature Reserve and privately owned
wetlands on the property of Wilgara, 20 km east of the reserve. The Macquarie Marshes contain a
wide range of vegetation types including river red gum woodland, water couch grasslands, coolibah
and black box woodlands, lignum swamps, reed swamps, cumbungi and river cooba. The diversity of
vegetation communities within the marshes provides habitat for an array of wildlife including 211 bird
species, eight species of native mammal, 15 frog species, 56 reptile species and 24 native fish
species (DEWHA 2009).
The Macquarie Marshes were listed as a Ramsar site in 1986 after meeting five of the nine criteria,
with two of these specifically relating to their value as waterbird habitat. The marshes are significant
for colonial waterbirds, being one of the few remaining sites in Australia to support large breeding
colonies of straw-necked ibis. They are also one of the few sites in NSW where magpie geese breed,
and support some of the largest breeding colonies of intermediate egret, rufous night heron and royal
spoonbill in southern Australia. The marshes regularly support more than 20,000 waterbirds and over
500,000 in large floods, including substantial numbers of cormorants, herons, ibises, spoonbills,
swans, geese, ducks, raptors, and migratory waders (DEWHA 2009).
The wet conditions and high river flows in 2010 resulted in flooding of around 50,000 ha of the
marshes. More than 35,000 waterbirds were recorded breeding in the wetlands in December 2010
including ibis, egrets and cormorants (ABC News 2010).
Gum Cowal wetlands in the Macquarie Marshes January 2011
Debbie Love, DECCW
4.4 Significant biodiversity
The aquatic and terrestrial environments of the Macquarie-Bogan Catchment support a range of
threatened species and ecological communities that are protected under the Threatened Species
Conservation Act 1995. Within the Central West CMA region (which includes the Macquarie, Bogan
and Castlereagh) there are 42 threatened plant species with 17 of these listed as endangered. The
majority of these are associated with the slopes and ranges of the upper catchment. The catchment
also provides habitat for 66 threatened animal species including 36 birds, five frogs, nine bats, nine
mammals, six reptiles and one invertebrate.
Ten endangered ecological communities occur within the catchment. One of these, the Mount
Canobolas Xanthoparmelia Lichen Community is endemic to the Orange district. Other endangered
communities in the upper catchment include Tableland Basalt Forest in the Sydney Basin and South
Eastern Highlands Bioregions which occurs in the Bathurst and Oberon districts, and White Box
Yellow Box Blakely's Red Gum Woodland, a grassy woodland community.
Vegetation communities in the Lower Macquarie and Bogan catchments have been heavily affected
by clearing and the remaining native vegetation therefore increases in significance. The CoolibahBlack Box Woodland endangered ecological community occurs on the floodplain of the Lower
Macquarie and Bogan Rivers. In addition to the direct effects of land clearing, this community
continues to be threatened by fragmentation, overgrazing, weed invasion and the alteration of flood
regimes.
The endangered Artesian Springs Ecological Community occurs throughout the Great Artesian Basin
and some are known to occur in the lower Bogan catchment. The springs occur where artesian water
emerges at the surface, producing mounds from the salts and sediments as the water evaporates. The
community is threatened by grazing, feral pigs and lowering of the Great Artesian Basin.
Five fish species that potentially occur within the Macquarie-Bogan Catchment are listed as
threatened under the NSW Fisheries Management Act 1994 (Table 2). These are trout cod, river snail,
silver perch, purple spotted gudgeon and olive perchlet. A conservation stocking program has seen
trout cod restocked into the Macquarie River over the past decade but it is not known whether any
breeding populations have been established. Silver perch are stocked in Windamere and Burrendong
Dams for recreational fishing.
The aquatic community of the Macquarie and Bogan Rivers is part of the endangered community
known as the aquatic ecological community in the natural drainage system of the lowland catchment
of the Darling River. This includes 21 native fish species and hundreds of native invertebrate species
that are found within the Darling River and its associated streams, wetlands and anabranches within
NSW. The community occurs in lowland riverine environments with meandering channels and a
variety of aquatic habitats including deep channels and pools, wetlands, gravel beds and floodplains.
Table 2: Threatened aquatic species of the Macquarie-Bogan catchment
Common name
Scientific name
Status
Trout cod
Maccullochella macquariensis
Endangered
River snail
Notopala sublineata
Endangered
Silver perch
Bidyanus bidyanus
Vulnerable
Purple spotted gudgeon
Mogurnda adspersa
Endangered
Olive perchlet
Ambassis agassizii
Endangered Population
Darling River EEC
Aquatic ecological community in the natural
drainage system of the lowland catchment of
the Darling River
Endangered Ecological
Community
5 Surface water
The Macquarie River flows north-west for 960 km from its headwaters near Oberon to the Barwon
River upstream of Brewarrina, while the Bogan River flows north-west from its headwaters in the
Hervey Range near Peak Hill. The combined catchment of the Macquarie and Bogan Rivers covers
74,000 km2. While the Bogan River maintains its own catchment, running roughly parallel to the
Macquarie, the streams are hydrologically connected via several effluent channels from the Lower
Macquarie which provide regulated flows to the lower Bogan River.
5.1 Macquarie River upstream of Burrendong Dam
The Macquarie River rises in the Great Dividing Range near Oberon and is formed by the junction of
the Fish River and Campbells River upstream of Bathurst. From here it flows north-west before
entering Burrendong Dam upstream of Wellington. Major tributaries include the Turon and Crudine
Rivers; Queen Charlottes and Lewis Ponds Creeks; and Winburndale Rivulet. The rivers of the upper
catchment flow within well-defined channels and have only limited floodplains.
5.2 Cudgegong River
The Cudgegong River starts in the Great Dividing Range above Rylstone and flows west into
Windamere Dam near Mudgee. Below Windamere Dam the river continues into Burrendong Dam. The
three major tributaries of Lawsons, Wyaldra and Meroo Creeks flow into the Cudgegong River
between Windamere and Burrendong Dams. The upper reaches of the Cudgegong River flow through
narrow valleys, broadening into a wide alluvial floodplain below Mudgee.
Cudgegong River upstream of Rylstone
5.3 Burrendong Dam to Narromine
The Macquarie River flows north-west from Burrendong Dam through the major towns of Dubbo and
Narromine. It is joined by three major tributaries – the Talbragar River which begins at Coolah and
enters the river from the north, and the Bell and Little Rivers which begin near Molong and enter the
river from the south. Numerous small ungauged creeks also enter the river within this reach. Within
this reach the floodplain of the Macquarie River is well defined and relatively narrow, with flooding
being confined within the river banks.
5.4 Bogan River
The Bogan River starts in the Hervey Range near Peak Hill and flows north-west to Nyngan. The
western side of the catchment is drained by four major tributaries: Bullock, Bulbodney, Pangee and
Whitbarrow Creeks. The eastern catchment between the Bogan and Macquarie Rivers is ill-defined
and has only one major tributary, Mulla Cowal with a catchment area of 1,000 km2. The total
catchment area of the Bogan River upstream of Nyngan is approximately 18,000 km2.
5.5 Lower Macquarie River
From Narromine, the Macquarie River flows north-west across flat alluvial plains to join the Barwon
River between Walgett and Brewarrina. Three major tributaries flow into the Macquarie in this section:
Ewenmar Creek upstream of the marshes; Marthaguy Creek; and the Castlereagh River which enters
the Macquarie about 20 km upstream of the Barwon River.
The channel capacity of the river decreases progressively downstream of Narromine, and the Lower
Macquarie valley is characterised by numerous effluent channels. Between Marebone Weir and
Carinda the river flows for 120 km through a meandering network of effluent channels and
anabranches including the Macquarie Marshes. The marshes are a large wetland complex of shallow
swamps, lagoons, creeks and floodplains that cover more than 200,000 ha when fully flooded.
Major effluent streams of the lower valley include the Albert Priest Canal (an artificial channel),
Gunningbar Creek and Duck Creek which deliver regulated flows from the Macquarie River to the
lower Bogan River; Terrigal Creek which flows north to join Marthaguy Creek; and Crooked and Marra
Creeks which converge and flow north into the Barwon River.
Marthaguy Creek at Carinda
5.6 Stream flow characteristics
The NSW Office of Water maintains 91 river gauges within the Macquarie-Bogan catchment which
record flows on a continuous basis. Table 3 shows mean daily flows for some key locations throughout
the catchment. Like many of the western flowing rivers in NSW, the flow in the Macquarie River
decreases with distance downstream once it enters the flat alluvial floodplains of the lower valley.
Decreasing channel capacity, irrigation and the presence of numerous effluent channels reduces the
mean daily flow of the Macquarie from over 3,000 ML/day at Dubbo to less than 900 ML/day upstream
of the Macquarie Marshes. Further losses to the channels and wetlands of the marshes result in an
average flow of less than 400 ML/day being recorded at the Carinda gauge downstream of the
Macquarie Marshes (Table 3).
In contrast the flow in the Bogan River increases with distance downstream, as a result of the
regulated supplies of water that enter the lower Bogan River via the Albert Priest Canal, Gunningbar
Creek and Duck Creek. Upstream of these effluents at Neurie Plains near Nyngan the mean daily flow
is 241 ML, while downstream at Gongolgon the mean flow is over 700 ML/day (Table 3).
Table 3: Mean daily flow for selected Macquarie and Bogan River gauges
Catchment
2
area (km )
Mean daily
flow (ML)
Period of
record
Macquarie River at Bruinbun (upstream Burrendong)
4,580
1,162
1947-2009
Macquarie River at Wellington
14,130
2,712
1909-2009
Macquarie River at Dubbo
19,600
3,250
1885-2009
Macquarie River at Warren Weir
26,570
1,873
1901-2009
n/a
868
1943-2009
Macquarie River at Carinda (downstream marshes)
30,100
388
1926-2009
Bogan River at Peak Hill
1,036
74
1967-2009
Bogan River at Neurie Plain
14,760
241
1959-2009
Bogan River at Gongolgon
27,970
737
1945-2009
883
272
1949-2009
1,370
100
1948-2009
612
91
1965-2009
Cudgegong River downstream Windamere Dam
1,088
109
1970-2009
Cudgegong at Yamble Bridge (upstream Burrendong)
3,490
408
1956-2009
Duck Creek at Napali
n/a
41
1994-2009
Gunningbar Creek at Fairview
n/a
70
1994-2009
Marthaguy Creek at Carinda
6,475
382
1944-2009
Marra Creek at Billybingbone
n/a
148
1980-2009
Gauge site
Macquarie River at Oxley (upstream marshes)
Turon River at Sofala
Bell River at Gowan Green
Little River at Obley2
Source: NSW Office of Water Real Time Data – Rivers and Streams
Figure 8: Annual flow in the Macquarie River at Dubbo 1915-2010
10,000
Macquarie River at Dubbo
Annual Flow
Mean Annual Flow
Burrendong Dam
Completed
ML (x1000)
8,000
6,000
4,000
2,000
Mean Annual Flow = 1,175,360 ML
0
1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Years
The long-term average annual flow in the Macquarie River at Dubbo is 1,175,360 ML (1915-2010).
The Macquarie valley has been in a prolonged drought sequence for the past nine years, with 2010
being the first year since 2000 when above average flows have been recorded (Figure 8). The lowest
annual flow occurred in 1919 when just 24,145 ML was recorded, while the highest annual flow
occurred in 1950 when 10,113,000 ML were recorded over the year.
Daily streamflows provide an indication of the variability of flow patterns and the peak height of flood
events. There have been several large floods in the Macquarie River at Dubbo. The largest of these
since records began was in February 1955 when daily flow peaked at more than 440,000 ML (Figure
9). Despite the generally dry conditions that prevailed over the early half of the 1900s, there were
many more small to moderate floods during this period (with peaks of 100,000 to 250,000 ML) than in
the latter half of the century as a result of there being no means of mitigating the floods. Since the
regulation of the valley in 1967, which introduced significant flood mitigation capabilities, there have
only been three moderately large flood events, these being in 1971, 1990 and most recently in
December 2010. Widespread rain and flooding along the Macquarie River through December 2010
resulted in the largest flood event in the Macquarie River since 1990. The August 1990 flood produced
a peak height of 190,000 ML/day at Dubbo, while the December 2010 flood peaked at
143,000 ML/day.
The cumulative mass curve in Figure 9 provides insight into long-term streamflow trends. The plot is
produced by calculating variations from the long-term mean, and can be interpreted according to the
following rules (Burrell and Ribbons 2006):

where the slope of the curve is rising the flow exceeds the long-term average, indicating
wetter periods

where the slope of the curve is falling the flow is less than the long-term average, indicating
generally drier periods

relative magnitude can be determined by the steepness of the slope and the y-axis of the
plot.
The cumulative mass curve shows that there was a prolonged dry period in the Macquarie catchment
between 1910 and 1950 with long periods of below average flow. A significant shift towards wet
conditions occurred with the large flood events during the 1950s. From the late 1950s to the year 2000
the catchment experienced a series of alternating wet and dry periods lasting around a decade each.
The valley fell into a prolonged drought sequence in 2001 until late 2010 with the sharp upturn in the
graph reflecting the recent flooding.
Figure 9: Daily flows in the Macquarie River at Dubbo and cumulative deviation from the mean
Macquarie River at Dubbo (421001)
1915 to 2010
450,000
Daily Flow
400,000
350,000
ML/d
300,000
250,000
200,000
150,000
100,000
50,000
0
1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Years
8,000
Cummulative Variation from Mean
6,000
4,000
2,000
ML/d (x1000)
0
Mean Flow = 3,250 Ml/d
‐2,000
‐4,000
‐6,000
‐8,000
‐10,000
‐12,000
‐14,000
‐16,000
1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Years
6 Groundwater
Alluvium is an importance source of groundwater in the Macquarie valley for stock, domestic, irrigation
and town water supplies. Together with the adjacent Castlereagh valley, the Macquarie region
accounts for around 11 per cent of the total groundwater use in the Murray-Darling Basin
(CSIRO 2008).
The majority of groundwater use occurs in the alluvial sediments associated with ancient channels of
the Macquarie River downstream of Dubbo (Figure 10). Here the alluvium may be up to 150 m thick,
although generally the thickness is 50 m or less (DEWHA 2009). The thickest deposits and highest
yielding bores are confined to a relatively narrow ancient valley which trends generally west to northwest from Narromine as a continuation of the present day Macquarie valley. In this area the aquifers
consist of medium to coarse quartz sand and gravel layers interbedded with clay, silt, and sandy clay
(DEWHA 2009).
Other smaller but important areas of alluvium are associated with the floodplains of the upper
catchment such as the Cudgegong, Talbragar and Bell Rivers. Sediments in the Cudgegong valley are
up to 12 m thick while those in the Dunedoo area of the Talbragar valley may be up to 75 m thick
(WRC 1984).
Much of the upper Macquarie catchment and the Bogan catchment is underlain by fractured rock
which yields very little groundwater (Figure 10). The Bogan catchment is generally unfavourable for
the development of groundwater resources with aquifers in the alluvium being thin and low yielding,
and the groundwater generally brackish or saline (WRC 1984).
Figure 10: Groundwater aquifer types of the Macquarie-Bogan catchment
Figure 11: Groundwater Management Areas of the Macquarie-Bogan catchment
Figure 12: Groundwater quality and suitability in the Macquarie-Bogan catchment
Groundwater in the catchment is managed according to 14 different Groundwater Management Areas
which are based on underlying geology (Figure 11). The Lower Macquarie Alluvium Groundwater
Management Area covers the main high yielding aquifers northwest of Narromine. A water sharing
plan commenced for this management area in 2006 (see section 7.4).
The Great Artesian Basin underlies the northern part of the Macquarie catchment downstream of
Warren. A water sharing plan for the aquifers of the Great Artesian Basin commenced in 2008
(section 7.4).
Groundwater is generally fresh to moderately fresh in the upper and middle parts of the catchment,
making it suitable for most stock, domestic and irrigation purposes. However in the Lower Macquarie
downstream of Warren, and through much of the Bogan catchment, groundwater is brackish to saline
and suitable only for limited stock use (Figure 12).
The NSW Office of Water monitors groundwater levels and quality at 163 sites throughout the Lower
Macquarie Groundwater Source (DWE 2009a).
Groundwater monitoring bore on a property near Trangie
7 River operations and management
7.1 Major storages and regulating structures
Burrendong Dam is located on the Macquarie River upstream of Wellington and is the largest storage
in the catchment. It was completed in 1967 to provide storage for irrigation, town water, stock and
domestic requirements for the Macquarie valley. It incorporates 489,000 ML of airspace for flood
mitigation purposes, and also stores water for environmental purposes, in particular for watering of the
Macquarie Marshes wetlands.
Windamere Dam is on the Cudgegong River about 22 km upstream of Mudgee. The earth and rockfill
dam was completed in 1984 to provide town water supply for Mudgee and Gulgong and water for
irrigators and other water users along the Cudgegong River.
A number of other smaller dams within the upper Macquarie catchment provide for town water
supplies (Table 4). Oberon Dam on the Fish River is operated as part of the Fish River Water Supply
Scheme and was completed in 1946. It services a number of water users including the towns of
Lithgow and Oberon. Water is also transferred by Sydney Catchment Authority to meet urban water
demands in the upper Blue Mountains, and Delta Electricity has an entitlement for use in their
Wallerawang power station.
Ben Chifley Dam is the major water storage for Bathurst City Council. Located on Campbells River,
water is released from the dam and diverted by Council from the Macquarie River downstream. Suma
Park Dam was completed in 1962 and is the major water supply for the city of Orange. The towns of
Rylstone and Kandos are supplied from Rylstone Dam on the Cudgegong River upstream of
Windemere.
Downstream of Burrendong Dam there are five weirs that regulate the diversion of water within the
Lower Macquarie River.

Dubbo, Narromine and Gin Gin weirs are all ponding structures that provide pumping pools
for irrigation diversion.

Warren Weir controls the diversion of flow into Gunningbar Creek from which further
regulators supply Duck Creek, Crooked Creek and the Albert Priest Canal.

Marebone Weir is located just upstream of the Macquarie Marshes. It supplies water to
Marra Creek on the southern side of the river, and Bulgeraga Creek (via Marebone Break)
on the northern side of the river.
Table 4: Major storages in the Macquarie catchment
Burrendong
Windamere
Oberon
Ben Chifley
Suma Park
River
Macquarie
Cudgegong
Fish
Cambells
Sumerhill
Creek
Capacity (ML)
1,190,110
353,000
45,400
30,800
18,000
Purpose
Irrigation,
flood
control
Irrigation
Town water,
industrial
Town water
Town
water
Catchment area
13,900 km2
1,070 km2
140 km2
960 km2
179 km2
Nearest town
Wellington
Mudgee
Oberon
Bathurst
Orange
Burrendong and Windamere Dams
There are three major weirs on the Bogan River which provide pumping pools for groups of local
irrigators. These are Muddal Weir, Nyngan Weir and Gongolgon Weir. Nyngan weir also provides
storage for town water supplies for Nyngan and Cobar which are delivered from the Macquarie River.
In addition to these major structures numerous small regulators control water diversions into the
various effluent channels and artificial supply channels.
7.2 Irrigation areas
There are seven private off-river irrigation schemes in the Macquarie catchment: Narromine, TrangieNevertire, Tenandra, Buddah Lake, Marthaguy, Nevertire and Greenhide (Table 5). Together these
irrigation schemes account for approximately 40 per cent of all the licensed irrigation entitlement in the
catchment. The largest of the irrigation areas are Narromine and Trangie-Nevertire, both established
in 1970 following completion of Burrendong Dam. The Narromine scheme covers 120 km2 and
services 90 properties via 350 km of channel. The Trangie-Nevertire scheme covers 102 km2 and
services 66 farms via 250 km of channel (MDBC 2007).
Cotton is the predominant crop and is concentrated on the floodplains around Narromine, Trangie and
Warren. Cotton is an annual crop that can only be grown when there is sufficient water available. A
range of summer and winter cereals, pulses and oilseeds may also be grown under irrigation in
rotation with cotton.
Table 5: Private irrigation schemes in the Macquarie catchment
Entitlement (ML)
2
Area (km )
Members
Channel length (km)
Narromine
60,100
120
90
350
Trangie-Nevertire
63,500
102
66
250
Tenandra
34,800
32
150
Buddah Lakes
32,500
170
19
58
Marthaguy
16,600
35
16
Nevertire
32,000
Greenhide
7,800
Scheme
Source: MDBC 2007
8.3
15
50
10
30
7.3 Licensed water use
Combined with the adjacent Castlereagh valley, the Macquarie-Bogan catchment uses approximately
4 per cent of the surface water diverted for irrigation in the Murray Darling Basin, and accounts for
approximately 11 per cent of groundwater use (CSIRO 2008).
7.3.1 Surface water
The Macquarie River system is operated (or regulated) to meet the needs of a variety of water users
including general security and high security irrigators, stock and domestic users and town water
supplies. Water is allocated and released from Windemere and Burrendong Dams to meet these
needs.
The regulated Macquarie system is operated using the two main storages as a combined resource
(however there are rules associated with bulk transfers) and managed using an annual accounting
system. The maximum volume of water that can be carried over from water year to the next for
general security licence holders is 1 ML per share (however there are some provisions associated with
the Cudgegong system). No carry over is permitted for all other types of access licences.
A long-term extraction limit has also been set in place for areas under the regulated river water
sharing plan that limits growth in diversions for consumptive purposes. This limit aims to ensure
approximately 73 per cent of long-term average flow is preserved for the environmental health of the
ecosystem.
Water users situated on the various creeks and tributaries including the Bogan River, that are not
currently managed by a water sharing plan may extract water with an unregulated water licence.
These licences are subject to a range of access conditions that protect the health of the water courses
such as cease-to-pump conditions. As of December 2010 the licensed entitlement of unregulated
water users in the Macquarie catchment was 145,448 ML (Table 6).
Table 6: Surface water entitlements for the Macquarie-Bogan catchment 2009-10
Access licence category
General security
Total share component (ML)
631,716
High security
18,213
Supplementary
50,043
Stock and domestic
Local water utility
Unregulated (Water Act
1912)
5,576
18,805
145,448
Source: NSW Office of Water, Water Access Licence Statistics 2009-10
7.3.2 Groundwater
Between 2000 and 2006 groundwater use in the Macquarie valley ranged from 61,000 to
119,000 ML/year, with the average annual extraction for this period being 93,000 ML (MDBC 2007).
In 2009 there were nearly 13,000 bores in the Macquarie valley which were licensed to provide over
188,000 ML of groundwater per year. Forty-three per cent of this entitlement (nearly 82,000 ML) is
associated with the Water Sharing Plan for the Lower Macquarie Groundwater Sources (see Section
7.4). Aquifer licences within the water sharing plan area cover a variety of purposes including
irrigation, industrial, stock and domestic water. Outside the water sharing plan, the main licensed use
of groundwater is for irrigation and stock. There is a large reliance on groundwater for town water
supplies with 13,758 ML of entitlement being held by local water utilities within the catchment.
Table 7: Groundwater entitlements for the Macquarie-Bogan catchment 2009
Access licence category
Total share component (ML)
Within water sharing plan area
Local water utility
4,658
Aquifer access
74,945
Supplementary access
2,396
Total in WSP
81,999
Outside water sharing plan area
Aquaculture
60
Commercial
125
Dewatering / mining / industrial
3,546
Domestic
2,220
Research / teaching
38
Farming
437
Fire fighting
3
Irrigation
60,549
Recreation
975
Stock
29,586
Town water supply
9,100
Total outside WSP
106,639
TOTAL
188, 638
7.4 Water sharing plans
A water sharing plan is a legal document prepared under the Water Management Act 2000. It
establishes rules for sharing water between the environmental needs of the river or aquifer and water
users, as well as between different types of water users. Water sharing plans provide security for the
environment and water users by setting the rules for how water is allocated over a 10 year period. In
addition, the plans set rules for water trading and annual water allocations.
The purpose of a water sharing plan is:

to protect the environmental health of the water source

to ensure that the water source is managed sustainably in the long term

to provide water users with certainty about when and how water will be available for
extractions.
There is currently one surface water sharing plan and two groundwater sharing plans that cover the
Macquarie and Bogan River catchments. A further three water sharing plans covering groundwater
sources of the Macquarie catchment are currently in preparation. Commenced plans can be viewed on
the NSW Office of Water website www.water.nsw.gov.au.
7.4.1 Surface water sharing plan
Macquarie and Cudgegong Regulated Rivers
The Water Sharing Plan for the Macquarie and Cudgegong Regulated Rivers Water Source
commenced on 1 July 2004 and will apply for 10 years until 2014. The plan provides water for the
environmental needs of the Macquarie and Cudgegong Regulated Rivers Water Source and directs
how the water available for extraction is to be shared. The water sharing plan also sets rules that
affect the management of water access licences, water accounts, water trading, dam operations, and
flow management.
The plan applies to the regulated sections of the Macquarie and Cudgegong Rivers, including the
regulated sections of Gunningbar, Duck, Crooked and Bulgeraga Creeks. While the Macquarie
marshes are not part of the plan area, the plan includes rules about the release of flows to improve
environmental outcomes within the marshes. The plan also provides replenishment flows for a number
of water sources in the Lower Macquarie and lower Bogan River systems.
The major environmental provisions for the regulated Macquarie water source are (DIPNR 2004):
1. All flows above the plan extraction limit are reserved for the environment.
On a long-term average basis, approximately 73 per cent of yearly flows in the river are
protected for environmental health.
2. Provide more natural flows in the upper reaches of the Cudgegong River.
This is achieved by releasing a portion of inflows to Windamere Dam to attain, in
combination with downstream tributary contributions, a flow of 150-1,500 ML/day at Rocky
Water Hole. No releases occur when the capacity of Windamere Dam is less than
110,000 ML, and releases are subject to an annual limit of 10,000 ML.
3. Establish an environmental water allowance for the Macquarie River.
The plan allows for up to 160,000 ML to be credited to an environmental water allowance in any water
year. Part of this allowance (sub account 1) is used to provide more natural flows downstream of
Burrendong Dam. Releases are made during the periods 1 June to 30 November, and 15 March to 31
May each year to attain, in combination with downstream tributary inflows, a flow of between 500 and
4,000 ML/day at Marebone Weir. The other part of the environmental water allowance (sub account 2)
is released when needed for special environmental purposes such as enhancing native fish
recruitment, ensuring completion of water bird breeding events, and alleviating severe, unnaturally
prolonged drought conditions in the Macquarie Marshes. An Environmental Flow Reference Group
provides advice on when the water should be released for environmental purposes.
The Water Sharing Plan for the Macquarie and Cudgegong Regulated Rivers Water Source was
suspended in July 2007 due to extreme drought conditions within the catchment. Despite this, water
has been made available to the environment through the environmental water allowance. In 2007-08
approximately 13,000 ML of water held in the Environmental Water Allowance account was released
in January 2008, and a further 8,000 ML was released in March-April 2008. These two releases were
made to support successful bird breeding events in the Macquarie Marshes (DWE 2009b). With a
return to wetter conditions in 2010 the Macquarie and Cudgegong Regulated Rivers plan is due to
recommence as of 1 July 2011.
7.4.2 Groundwater sharing plans
Lower Macquarie Groundwater
The Water Sharing Plan for the Lower Macquarie Groundwater Sources commenced on 1 October
2006 and will apply until 30 June 2017. The plan defines long-term extraction limits for each of six
groundwater management zones.
Three categories of groundwater access licences are included in the plan – Local Water Utility Access
Licences, Aquifer Access Licences and Supplementary Water Access Licences. At the start of the
plan a total of 3,093 ML of water was available for Local Water Utility licences for town water supply.
The plan provides 65,524 ML for Aquifer Access licences and 2,399 ML for Supplementary Access
licences.
NSW Great Artesian Basin Groundwater
The Water Sharing Plan for the NSW Great Artesian Basin Groundwater Sources commenced on
1 July 2008 and will apply for 10 years. The Great Artesian Basin (GAB) underlies the northern half of
the Macquarie-Bogan catchment.
The water sharing plan covers all water contained in the sandstone aquifers of the NSW portion of the
GAB. The GAB has been divided into five groundwater sources – the Eastern and Southern Recharge
Groundwater Sources are in the non-artesian part of the basin, while the Surat, Warrego and Central
Groundwater Sources are in the artesian part of the basin, where water flows naturally to the surface.
The two groundwater sources covering the Macquarie surface water catchment are the Southern
Recharge and the Surat groundwater sources.
The basis for determining how water is shared in the Southern Recharge Groundwater Source is the
average annual net recharge. This is the volume added to the groundwater source from rainfall and
river flows on a long-term average basis, minus an allowance for groundwater outflow to adjacent
groundwater sources. The average annual net recharge is 42,400 ML/year for the Southern Recharge
Groundwater Source.
The basis for water sharing in the Surat Groundwater Source is the sustainable pressure estimate
equivalent. This is the volume of water required to maintain pressure levels experienced under the
water management regime and infrastructure that was in place in 1990. For the Surat Groundwater
Source the sustainable pressure estimate equivalent is 75,000 ML/year (DWE 2009c).
The plan has the following provisions for the protection of the environment (DWE 2009c):
1. In the Southern Recharge Groundwater Source 30 per cent of the average annual net
recharge is set aside for the environment to provide for the needs of groundwater
dependent ecosystems.
2. In the Surat Groundwater Source the volume of water required to maintain 1990 pressure
levels, plus water savings made under the Cap and Pipe the Bores Program between 1990
and 1999, plus 70 per cent of water savings made under that program since 1999, are set
aside for the environment.
7.4.3 Plans in preparation
A number of groundwater sharing plans were placed on public exhibition in December 2010 and are
expected to be finalised in 2011. The following are relevant to the Macquarie-Bogan catchment.
Groundwater Sources Overlaying the Great Artesian Basin
Within this plan the GAB Macquarie Groundwater Source includes the aquifers of the unconsolidated
and low permeability consolidated and semi-consolidated sediments that overlie the GAB Surat
Groundwater Source. The water source is associated with the surface water catchment of the
Macquarie.
NSW Murray-Darling Basin Fractured Rock Water Sources
Three water sources covered by this plan occur within the Macquarie catchment. These are related to
the fractured rocks of the Lachlan Fold Belt, Liverpool Ranges Basalt and Orange Basalt.
NSW Murray-Darling Basin Porous Rock Groundwater Sources
This plan covers two water sources within the Macquarie catchment that are associated with porous
rock types. These are the aquifers associated with the Gunnedah-Oxley Basin and the Sydney Basin.
8 References
Australian Broadcasting Commission 2010, Floodwaters rejuvenate Macquarie Marshes. ABC News,
6 December 2010. Accessed online 17/02/2011,
http://www.abc.ne.au/news/stories/2010/12/06/3085203.htm
Burrell M and Ribbons C 2006, NSW Drought Analysis: Comparison of the Current Drought Sequence
Against Historical Droughts, Department of Natural Resources, Parramatta.
CSIRO 2009, Water availability in the Macquarie-Castlereagh. CSIRO Canberra, March 2008.
Accessed online 22/12/2009, http://www.csiro.au/partnerships/MDBSYReports.html
Department of Environment, Water, Heritage and Arts 2009, The Macquarie Marshes. Australian
Wetlands Database: Australian Ramsar Sites. Accessed online 7/12/2009,
http://www.environment.gov.au/cgi-bin/wetlands/ramsardetails.pl?refcode=28
Department of Water and Energy 2009a, Water sharing in the major inland alluvial aquifers. Progress
report 2006 to 2008. NSW Department of Water and Energy, Sydney, May 2009. Accessed
online 22/12/2009, http://www.water.nsw.gov.au/Water-Management/Watersharing/plans_commenced/default.aspx
Department of Water and Energy 2009b, Water sharing in the Macquarie and Cudgegong Regulated
Rivers: Progress report 2004 to 2008, Department of Water and Energy, April 2009.
Accessed online 22/12/2009, http://www.water.nsw.gov.au/Water-Management/Watersharing/plans_commenced/default.aspx
Department of Water and Energy 2009c, Water Sharing Plan for the NSW Great Artesian Basin
Groundwater Sources – Guide. NSW Department of Water and Energy, January 2009.
Hutchinson MF and Kesteven JL 1998, Monthly mean climate surfaces for Australia. Australian
National University, December 1998.
Murray Darling Basin Commission 2007, On-farm water use efficiency in the Northern Murray-Darling
Basin, MDBC Publication No. 03/08, Canberra.
National Parks and Wildlife Service 1993, Macquarie Marshes Nature Reserve Plan of Management.
NSW National Parks and Wildlife Service, May 1993. Accessed online 7/12/2009,
http://www.environment.nsw.gov.au/parkmanagement/ParkManagementPlans.htm
National Parks and Wildlife Service 2002, Coolah Tops National Park Plan of Management. NSW
National Parks and Wildlife Service, November 2002. Accessed online 7/12/2009,
http://www.environment.nsw.gov.au/parkmanagement/ParkManagementPlans.htm
Water Resources Commission 1984, Groundwater in New South Wales, NSW Water Resources
Commission, Sydney.

Macquarie-Bogan catchment

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