Introduction

The Avon River SWMA is located in south eastern Victoria and covers approximately 1,829 km² (1% of the State). The management area forms the eastern river system of the Thomson River Basin.

The Avon River flows through the forested highlands of the Avon Wilderness Park, then through foothills and a confined floodplain before discharging into Lake Wellington. The main tributaries include the Valencia and Freestone Creeks. The southern section of the basin is relatively flat and the Gippsland Plains are topographically uniform. Extensive clearing of the foothills and the plains has left only small areas of forest remaining. The average annual rainfall in the highlands exceeds 1,000 mm, and declines towards the south of the basin, with Stratford receiving 619 mm per year.

There are no major storages located within the management area.

Major land-use in the basin includes agriculture, which is concentrated around the Avon River flats. Dairying is the main farming activity, mixed farming of beef cattle and sheep for wool and meat is also common, as is vegetable growing. There is also some gravel and sand extraction in the lower reaches of the river.

The mean annual flow of the basin is 239,000 ML, which is 1.2% of the total runoff generated in the State.

The average annual water use in the Basin is 47,030 ML; 99 % for irrigation, 0.5 % for urban and industrial use, and 0.5 % for rural use.

It should be noted that this estimate of water use does not take account of the volume reclaimed or returned water.

An average of 39,380 ML of water is imported from the Thomson-Macalister Rivers SWMA annually, mostly for irrigation. No water is exported from the basin.

Vital Statistics:

A four-class classification system was developed to provide a simple method to communicate the status of the use and allocation of Australia's water resources in relation to sustainable water management.

It is important to recognise that adequately quantifying a sustainable flow regime or sustainable yield and consequent operating rules is a complex matter. State, Territory and scientific agencies continue to develop and apply methods and measures for determining sustainable flow regimes and sustainable yields.

This categorisation provides a general guide only. Please refer to the State and Territory Overview and Technical reports for detail on the analysis methods used.

* Water use as a percentage of sustainable flow regime (surface water) and sustainable yield (groundwater)

PLEASE NOTE:

Sustainable Yield:

While Victoria has a variety of programs under way aimed at identifying, improving and protecting environmental water requirements, the necessary investigations take considerable time and resources.

Given the short time frame of the Audit, it was necessary to make some broad assumptions, and use a variety of approaches, to derive estimates of the sustainable yield for surface water management areas (SWMAs) in Victoria. Consideration was given to environmental water requirements (known and likely), existing user rights, and related social and economic impacts. The reported allocations to the environment represent the water that can currently be maintained or made available in an attempt to meet environmental water requirements.

For surface water management areas in the southern part of Victoria where environmental values could potentially be threatened by further allocations, the sustainable yield was limited to the current allocation volume, pending the outcomes of further detailed investigations of environmental water requirements.

The sustainable yield for the Avon River basin has been limited to the current allocation volume pending the outcomes of the Gippsland Lakes environmental study and the Avon SFMP

In the longer term, there may be further scope for freeing up additional water to improve environmental regimes by improving distribution and water use efficiencies (other options for improving environmental regimes will be considered as part of the Victorian River Health Strategy). In SWMAs where a significant portion of the available resource is committed to a downstream SWMA, there is also potential for trading of entitlements between the two SWMAs. This will result in a change to both the sustainable yield and the environmental allocation in both SWMAs. Trade out of a SWMA would decrease the sustainable yield of the SWMA and a trade of water rights into a SWMA would increase the sustainable yield. However, the sum of the sustainable yields for the two SWMAs would remain unchanged.

PLEASE NOTE:

Categorisation:

The categorisation of SWMAs in terms of the current level of water resource development has been determined with consideration given to the level of allocation and actual diversion of the resource relative to the assessed sustainable yield.

 Category 1: Low level of development: 0-30% Category 2: Medium level of development: 31-70% Category 3: High level of development: 71-99% Category 3*: Fully developed: 100% Category 4: Over allocated/used resource:>100% 

The development category for the Avon River SWMA has been reported as fully developed (Category 3*) with respect to allocation and as a high level of resource development (Category 3) with respect to diversion. The 3* rating for allocation has been assigned, pending the outcomes of the Gippsland Lakes environmental study and the Avon River SFMP.

How saline are the surface water resources in the Avon River surface water management area?

Table: Surface water resource by salinity class.

Major water storages

Table: Major water storage areas:

There were no major water storages reported in this area as part of the assessment

Further Information

• View the Victoria Water Resources Assessment 2000 Report
• View the Victoria Water Resources Assessment 2000 Technical Report
• Link to data available for download on the:
• Surface Water Management Areas
• Data from the 1985 Review of Australia's Water Resources and Water Use
• Link to the Map Maker to make a map using this information.
• For more information about water and other natural resource issues link to www.dse.vic.gov.au