Directory of Important Wetlands

Directory of Important Wetlands in Australia - Information sheet

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Millewa Forest - NSW053

Level of importance: National - Directory
Location: Murray Riverine Plains at 35 degrees 35' S to 36 degrees 01' S, 144 degrees 53' E to 145 degrees 22' E. Located approximately 5-10km south of Deniliquin along the Murray River from approximately 20 km downstream of Tocumwal to Barmah, as well as along the Edward River upstream of Deniliquin.
Biogeographic region: Riverina.
Area: 33 636 ha.
Elevation: 96 - 100 m ASL.
Other listed wetlands in same aggregation: Not given
Wetland type: B1, B2, B6, B10, B14, B4
Criteria for inclusion: 1, 2, 3, 4, 5,
Site description:
Physical features:
The Millewa Forest is situated on the broad floodplain of the Murray River which forms part of the Riverina Plains. The geology of the area consists of Quaternary fluvial and aeolian sediments which were formed as a result of a major period of deposition characterised by vast internal drainage areas and a broad distributary pattern. The main topographic relief and the factor which has had a major influence on the landscape and ecological development of the area is the Cadell Tilt, a fault line which resulted in a dam being created across the then course of the Murray River. This caused the river to abandon its original course and split into two arms, the Murray going south around the tilt and then northwest, and the Edward north and then west to rejoin at the Wakool junction nearly 200km downstream (Forestry Commission, 1985). As a result of this fault gradient has been reduced and flow restricted, profoundly affecting flood regimes and encouraging both the deposition of sediment within a broad deltaic floodplain area from the upstream and the developments of a complex pattern of distributary effluent streams. Downstream of the fault, the previous course of the Murray River parallels the present and provides an alternative course when the Murray floods. Occasional aeolian sandridges characterise parts of the Millewa Forests (Forestry Commission, 1985). Surface soils range from coarse to very fine alluvia except for the sandridges. Deep profiles show the soils to be stratified layers varying from fine clays to coarse sands. Extensive cracking of the surface soil is typical of the area, commencing with rapid drying conditions during summer (Forestry Commission, 1985). The climate of the area is marginally semi-arid and mean average rainfall is generally low, in the 350-450mm range, with summer months averaging approximately 30mm and winter months 40mm. summer rainfall is usually in the form of thunderstorms (Forestry Commission, 1985). Mean annual temperatures of Deniliquin are 31.8 degrees C in spring, 23.7 degrees C in Autumn and 15.4 degrees C in winter (Deniliquin Council pers. com.). These figures are indicative of the Millewa Forest.
Hydrological features:
The wetland occurs on the floodplains of the Murray and Edward Rivers. The Murray River is fed from the high winter/spring rainfall and winter snow areas of the Great Dividing Range, resulting in periodic flooding of the Millewa Forest. Most streams in the area flow from, rather than into the Edward and Murray Rivers, causing extensive flood-prone areas. Significant flooding of the area naturally occurred four years out of five and increased river flows would cause effluent streams to run. Initially, only permanent streams such as the Edward River would run, but at increased levels. As flows increased further, others would run. Eventually, when flows exceeded the channel capacity of the main streams, a general overbank flow would occur, flooding the forests of the area. Therefore, under natural conditions, forest floods would only normally occur in the winter / spring flood, and at least once every two years. The current hydrological regime, however, is significantly altered from the natural regime as a result of river regulation. The flows within the Millewa Forest are regulated to increase the availability of irrigation water for areas to the west. This raises the summer flow to levels which can be retained within the main rivers and a considerable volume of water is diverted upstream from the area for irrigation purposes. There are two dams within the catchment which have a joint capacity of 7 million megalitres. This alteration of the flow regime has had a twofold effect on the hydrological conditions in the floodplain. The higher summer level has increased the area of permanent swamps or lakes connected to the Murray or Edward Rivers by low offtake creeks, and the filling of the storage dams has resulted in less water being available for the natural winter / spring inundation of the floodplain . The effects of regulation are great in all but major flood years when the volume of water passing down the system is much greater than the total storage capacity of the dams. The number of floods has decreased and the period between floods has been extended since the implementation of river flow regulation. Controlled inundation of extensive areas is practised so as to maintain the breeding of colonial nesting waterbirds, following initiation of breeding by high winter-spring flows (Forestry Commission of NSW 1985).
Ecological features:
The area is contiguous with Victoria's Barmah Forest (23 500 ha)., The higher areas of the floodplain are forested with River Red Gums (Eucalyptus camaldulensis), while the low-lying marshes are dominated by Giant Spike Rush, with a dense emergent growth of Water Spike Rush and Mud Grass. There are seven vegetation types within the Millewa area (Australian Heritage Commission, 1998). These include a large River Red Gum (Eucalyptus camaldulensis) open forest / woodland which is the major vegetation type and occurs in areas which are regularly flooded (these forests have a grassy understorey including rushes and sedges, woody shrubs are uncommon and usually situated around watercourses), areas of Black Box (Eucalyptus largiflorens) open forest / woodland occurs on the outer margins of the forests on the drier sites (may be pure or associated with River Red Gum (Eucalyptus camaldulensis) or other Box species, understorey is shrubby with Lignum (Muehlenbeckia sp.) common, grasses include Wallaby Grass (Danthonia sp.) and Speargrass (Stipa sp.)), Yellow Box (Eucalyptus melliodora) open forest / woodland is found on sand ridges and has a similar understorey species composition to the Grey Box (Eucalyptus microcarpa) community, Grey Box (Eucalyptus microcarpa) open forest / woodland on sand ridges and on the drier margins of the forests (may occur in pure stands or with other box species, White Cypress Pine (Callitris glaucophylla) and Buloke (Casuarina luehmannii) may also be present, understorey is grassy and dominated by Wallaby Grass (Danthonia sp.), chenopods including Rhagodia sp., Saltbushes (Atriplex sp. and Maireana sp.) are also common), swamp communities dominated by rushes and reeds including extensive beds of Giant Rush (Juncus ingens) with a dense emergent growth of Bulrush (Typha sp.), and Common Reeds (Phragmites australis) are generally found in permanent shallow water and have a tall grassland formation (in more open communities a range of aquatic plants such as Water Spike-rush (Eleocharis sp.), Water Primrose (Ludwigia sp.), Water-milfoil (Myriophyllum sp.), Arrowgrasses (Triglochin spp.), and Cyperus sp. occur), dry grasslands (tussock grassland) occur as remnants on sand hills and on scattered strips along roadsides, wet grasslands which includes herblands and low closed grasslands occur between Red Gum Forests (Eucalyptus camaldulensis) and swamp communities where inundation prevents tree growth (major grasses include Moira Grass / Spiny Mudgrass (Pseudoraphis spinescens), Water Couch (Paspalum distichum), and Swamp Wallaby Grass (Amphibromus neesii)). These vegetation communities provide a wide variety of habitats for fauna species. Following flooding, large numbers of many species of waterbirds breed.
These forests remain a good example of the River Red Gum floodplain forests of inland NSW.
Notable flora:
The Millewa Forests support a number of important plant communities. These include the River Red Gum (Eucalyptus camaldulensis) community which is considered to be vulnerable and inadequately conserved in NSW, Yellow Box (Eucalyptus melliodora) and Grey Box (Eucalyptus microcarpa) communities which are considered to be vulnerable and not conserved in NSW and the Black Box, Common Reed (Phragmites australis) and Spiny Mudgrass (Pseudoraphis spinescens) communities which are considered to be inadequately conserved in NSW (Benson, 1989). The Millewa forests represent a substantial proportion of the River Red Gum forest in NSW, approx 29 000 ha (Forestry Commission 1985). A number of flora species which are considered nationally vulnerable (Nv) have been recorded within the Millewa Forests. These include the Daisy (Brachycome muelleroides) and, Small Scurf-pea (Psoralea parva). Swainsona microcalyx, Southern Daisy (Brachycome readeri), Slender Sunray (Rhodanthe stricta), Silky Umbrella Grass (Digitaria ammophila), Hypsela tridens, Cyperus flaccidus, Woolly Buttons (Leptorhynchos panaetioides), and Bears Ear (Cymbonotus lawsonianus) are considered to be regionally significant (Australian Heritage Commission, 1998).
Notable fauna:
The Plains-wanderer (Pedionomus torquatus), which is considered endangered at a state level (Se) has been recorded in the area. The Millewa Forest supports a number of fauna species considered vulnerable at a state level (Sv) including the Koala (Phascolarctos cinereus), Squirrel Glider (Petaurus norfolcensis), Large footed Mouse-eared Bat (Myotis adversus), Superb Parrot (Polytelis swainsonii), Brolga (Grus rubicundus), Freckled Duck (Stictonetta naevosa) and, Masked Owl (Tyto novaehollandiae) (Australian Heritage Commission, 1998). Fauna species recorded within the Millewa Forest which are listed on the CAMBA and / or JAMBA include the White-bellied Sea Eagle (Haliaeetus leucogaster), Cattle Egret (Ardeola ibis), and the Caspian Tern (Sterna caspia). Noteworthy fish species which have been recorded within the Millewa area include the Murray Cod (Maccullochella peeli) which is considered to be decreasing in abundance, and the Macquarie Perch (Macquaria australasica) which is considered to be threatened, although abundant in some areas (Lake, 1978). When flooded, the forests also support large numbers of waterbirds.
Other Fauna:
Social and Cultural values:
The Millewa Forests contain many sites which illustrate the history of human settlement in the Murray Region. These include a great diversity of Aboriginal sites which are found in the Millewa area including occupation sites, burial grounds, scar trees where canoes or shields have been cut, shell middens and mound sites on most sand ridges within the area (Australian Heritage Commission, 1998). Of significance to the local Aboriginal people are the meeting places where there ancestors met for corroborees and initiation ceremonies were held. Several areas and places throughout the Millewa forests have significant values to the Aboriginal people because of religious association and myth (Forestry Commission of NSW, 1985). A variety of European historic sites are also found in the area which illustrate the various phases of land utilisation within the region. For example the ?parkland? landscape i.e. the box woodlands with their grassy understories is derived from use of the land for grazing purposes, various remains of and the barges, wharves and punts represents Red Gum trading which was carried out in the area (Australian Heritage Commission, 1998). The forest is also a site for wetland ecological research.
Land tenure:
On site: State Forest. Surrounding area: State Forest, leasehold, Timber Reserve.
Current land use:
On site: Forestry including logging, charcoal production, grazing, water supply, bee keeping and recreation. Surrounding area: agriculture including wheat and rice, grazing (mainly sheep and cattle).
Disturbance or threat:
Past/present: Murray River regulation.

Potential: No information
Conservation measures taken:
The Barmah and Millewa Forests are listed on the Register of the National Estate. Water Management Plan prepared by State Forests of NSW and DLWC for the Millewa Forests. Rehabilitation of specific swamps including water management plan for Reedbed Swamps and rehabilitation of Moira Lake wetlands. A Management Plan for the Murray Management Area has been produced by the Forestry Commission of NSW which includes the Millewa group of forests.
Management authority and jurisdiction:
State Forests of NSW.
Australian Heritage Commission (1998); Benson, J. (1989); Bren, L.J. & Gibbs, N.L. (1986); Bren, L.J. et al.. (1987); Briggs, S.V. & Maher, M.T. (1983); Chesterfield, E.A. (1986); Chesterfield, E.A. et al.. (1984); Dalton, K.L. (1989); Dexter, B.D. et al.. (1986); Fahey, C. (1986); Forestry Commission of New South Wales (1985); Forestry Commission of New South Wales (1991); Francis, R.I.(1987); Johnson, K.E. & Meacham, I.R. (1980); Lake, J.S. (1978); Leslie, D.J. (1995); Maunsell Pty. Ltd. (1991); Murphy, A.W. (1990); Ross, A. (1989); Ward, K.A. (1991). See NSW Reference List
Compiler & date:
Geoffrey Winning & Michael Murray, Shortland Wetlands Centre, December 1992. Revised P. Bacon, Woodlots & Wetlands, 1995. Revised, Tania Laity, National Parks & Wildlife Service, 1998.
AWRC Division: Murray-Darling
AWRC Region:
AWRC Basin: