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Directory of Important Wetlands

Directory of Important Wetlands in Australia - Information sheet

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Ovens River - VIC144

Level of importance: National - Directory
Location: The Ovens River reach is located in north-east Victoria. The reach extends from Killawarra, downstream of Wangaratta, 36 degrees 15' S and 146 degrees 16' E, to the confluence of the Murray River, 36 degrees 02' S and 146 degrees 11' E. Lake Mulwala inundates the lower section of this reach.
Biogeographic region: Riverina and Victorian Midlands.
Shire:
Area: The river reach corridor has an area of 3750 ha, its boundaries follow the Public Land Water Frontage (PLWF) and streamside reserves downstream of Killawarra. Generally the corridor width varies from the narrow band of the PLWF (20 m wide) up to 2 km wide where the river flows across the broad floodplain (NRE in prep. f). Length of reach: 52 km.
Elevation: Top of reach: 140 m. Bottom of reach: 130 m. Range: 10 m.
Other listed wetlands in same aggregation: Billabong Creek and Chinaman Creek both contain a good riparian zone which is important to the river reach as a food source for birds. Chinaman Creek is also important as it forms a link between the Killawarra State Forest and the river.
Wetland type: B1
Criteria for inclusion: 3, 4, 6,
Site description:
The Ovens River flows in a north-westerly direction from the alps near Mount Feathertop and Mount Hotham to the Murray River. The selected reach is located lower in the landscape, close to the Murray River (NRE in prep. f).
Physical features:
Geology: The river reach consists mainly of finely-textured unconsolidated deposits particularly of alluvium, colluvium, swamp deposits, sand, gravel, silt, clay, peat and gypsum, found in the Cainozoic and Quaternary Age layers (DWR 1989a). Climate: The mean annual rainfall in the lower part of the reach at Yarrawonga, is 516 mm. Mean maximum temperatures at Yarrawonga range from 31.2 degrees C in January to 14.8 degrees C in August. Mean minimum temperatures range from 14.1 degrees C in February to 3.9 degrees C in July (BoM 1999a).
Hydrological features:
The Ovens River is unique in that is one of the few largely unregulated rivers found within the Murray Darling Basin in Victoria. Some water is removed, however, for domestic and agricultural use by private diverters who use approximately 16 460 ML per year. This water is stored in Lake Buffalo and Lake William Hovell and released for irrigation in summer. In the lower reach, where the river meets Lake Mulwala, there is an extensive network of billabongs, anabranches and islands. Above Wangaratta, 6000 ML of river water is diverted for domestic use. Since 1987, the lowest flow recorded was 50 ML in Wangaratta in January 1998. The river occasionally floods following heavy rainfall in the region, such as in October 1993 when there was extensive flooding and erosion as a result of exceptionally intensive rainfall (NRE in prep. f).
Ecological features:
The river reach has high nature conservation value, containing a significant rare flora community and the riparian vegetation provides an important habitat corridor for many significant fauna, particularly those which are dependent on mature trees. The in-stream condition of the river is largely in a natural state and provides habitat for many significant species, namely Murray Cod Maccullochella peeli peeli, Freshwater Hardyhead Craterocephulus stercusmuscarus and the Crimson-spotted Rainbow fish Melanotaenia splendia. Other species include: Golden Perch Macquaria ambigua, Flat-headed Galaxias Galaxias rostratus, Western Carp Gudgeon Hypseleotris klunzingeri, Australian Smelt Retropinna semoni, Southern Pygmy Perch Nannoperca australis, Flat-headed Gudgeon Philypnodon grandiceps, and Yabby Cherax destructor (NRE in prep. f). The wetlands, particularly at the lower end of the river corridor, also provide valuable habitat for many species of water-birds, namely the Great Egret Ardea alba (NRE in prep. f). There is a significant ibis rookery in this reach found near the crossing of the Murray Valley Highway (NRE in prep. f).
Significance:
River red gum Eucalyptus camaldulensis open forests and woodlands with shrub understorey of river bottlebrush Callistemon paludosus, Silver Wattle Acacia dealbata and native grasslands dominate the alluvial floodplains along the River Murray and tributaries. Agriculture has resulted in the reduction of this vegetation type. However, a large section remains along the Ovens River floodplain, from Spring Creek to Lake Mulwala. The forests below Spring Creek have State faunal importance as habitat for the large-footed myotis Myotis adversus, a bat with lower risk conservation status (NRE in prep. f). There is a high value of a large range of significant fauna including fifteen species of birds, five fish, one bat and four amphibians.
Notable flora:
River Red Gum forests are present throughout the reach and are of state significance (NRE 1990), there are also significant flora species such as the Silver Wattle Acacia dealbata, River Bottlebrush Callistemon paludosus, Rough-barked Honey Myrtle Melaleuca parvistiminea (Gullan et al 1990; DCE 1990d). There are nine threatened species within the Ovens River reach, of which two are listed nationally.
Notable fauna:
Threatened or vulnerable species within River Red Gum communities include the Large-footed Myotis Myotis adversus (R) and the broad-shelled tortoise Chelodina exspansa (NRE in prep. f). The Ovens River reach has high value for conservation of Murray Cod, Freshwater Hardyfish and the Crimson-spotted Rainbow fish. Other native species present in the reach include Golden Perch, Flat-headed Galaxias, Western Carp Gudgeon and Australian Smelt (NRE in prep. f). There are forty-eight threatened species within the Ovens River reach, of which three are listed nationally.
Other Fauna:
Social and Cultural values:
Recreation: Fishing, and canoeing are extremely popular along the river, there are also opportunities for boating, camping, bushwalking, swimming and educational nature study areas within the reach corridor.
Land tenure:
On site: Flora reserve, 230 ha; Lower Ovens Regional park, 790 ha; PLWF reserve, 70 ha and state forest 2660 ha. Surrounding area: Private land.
Current land use:
On site: Grazing, recreation, underground power cables (Eastern Energy), timber harvesting, nature conservation. Surrounding area: Grazing.
Disturbance or threat:
Past/present: Introduced flora and fauna species such as Patterson's Curse Echium plantagineum, Horehound Marrubium vulgare, Bathhurst Burr Xanthium spinosum, Noogoora Burr X. strumarium, Phalaris sp., foxes and rabbits are competing with native plant and animal species.

Potential: A decline in water quality due to salinisation may have impact on the many aquatic fauna species. Grazing and timber harvesting in the Red Gum forest has the potential to remove vegetation strata, with a resulting discontinuity in the habitat corridor for terrestrial fauna (NRE in prep. f).
Conservation measures taken:
North East Fire Protection Plan (DCE 1990d). Rivers and Streams Special Investigation Final Recommendations (LCC 1991a). North East Regional Landcare Plan (Consultative Reference Group 1993). North East regional Catchment Strategy (North East CALP Board 1997). Proposed Mid Murray Forest Management Plan (NRE in prep. c). NRE Draft Management Plan (NRE in prep. f). Heritage Rivers and Natural Catchment Areas Draft Management Plan (NRE 1997b).
Management authority and jurisdiction:
Management of land including State forest within the reach corridor is primarily the responsibility of the Department of Natural Resources and Environment (NRE). Parks Victoria is responsible for the management of the Lower Ovens Regional Park and a flora reserve. NRE manages the PLWF. The Environmental Protection Authority is responsible for water quality management in the river corridor. Goulburn Murray Water is responsible for the management of water diversions for stock, irrigation and domestic uses (NRE in prep. f). The North East Catchment Management Authority (CMA) is responsible for catchment management.
References:
See Victoria Reference List
Compiler & date:
Freshwater Ecology, Department of Natural Resources and Environment, May 2000.
Drainage:  
AWRC Division: Murray-Darling
AWRC Region: UPPER MURRAY
AWRC Basin: OVENS RIVER
Catchment:
Sub-catchment: