Goulburn-Broken River
Coordinator: Pat Feehan, Goulburn-Murray
Water
Introducing the Goulburn Broken Catchment
 The
Goulburn Broken Catchment in Victoria is one of
the CRC’s five focus
catchments. The information given below is
intended to give readers a feel for the physical
nature of the catchment, the key issues facing
catchment managers in the region, and key stakeholder
groups involved in catchment management and waterway-related
research.
Main rivers
The Goulburn Broken catchment is in central northern
Victoria and comprises the catchments of the Goulburn
and Broken Rivers and a small part of the Murray
Valley, upstream of Echuca. The catchment covers
a total of 2 391 544 ha, or 10.5% of Victoria’s
total land area. Some 250 000 people live in the
catchment.
Climate/hydrology
A number of the Goulburn’s major tributaries
rise on the northern slopes of the Great Dividing
Range. Rainfall varies substantially. The high
country in the south east experiences cool winters
with persistent snow and an average annual rainfall
greater than 1600 mm. Rainfall decreases northward
and in the far north of the catchment is less
than 450 mm per year, only one third of the annual
evaporation in that area.
The Goulburn catchment produces on average 1.8 ML/ha/yr while the drier Broken catchment produces 0.42 ML/ha/yr.
Terrain varies from the high ranges with an altitude greater than 1200m to the Murray Plain with an altitude of around 100m. The northern half of the catchment is relatively flat.
Vegetation
The catchment was once forested over its entire area. While native vegetation has been retained in the mountainous far south, where slopes are steepest, clearing for agriculture has been extensive in its valleys and plains. Approximately 50% of the catchment is used for dryland agriculture (cropping and grazing), about 30% is forested and the balance is irrigated.
Dams and rivers
Two major features, Lake Eildon and Goulburn Weir, have modified streamflow along the Goulburn River. Lake Eildon has a capacity of 3 390 000 ML and supplies more than half of the water used in the Shepparton Irrigation Region. The Goulburn Weir near Nagambie diverts water east and west to irrigated areas. This has substantially altered stream flows in the Goulburn River.
Industry
Extensive food processing industries in the region produce some 25 percent of Victoria’s rural economic output. The network of industries is recognised as one of the nation’s "food bowl" centres and these industries collectively have invested hundreds of millions of dollars in the introduction of world class technology and international best practice to their operations to maximise their export opportunities.
The continued well being of the region relies on supply of good quality water to primary producers and food processing industry.
Irrigation
Irrigation areas to the west also rely on water supplied from the Goulburn Broken catchment. Infrastructure investment by Goulburn Murray Water alone totals $2.6 billion. G-MW delivers rural water services to customers on 24 000 serviced properties across northern Victoria.
Catchment scale water issues
Water Quantity
- Catchment yield – there is concern about the potential impacts on water yield of large scale afforestation programs and irrigation development away from traditional irrigation areas. The potential impacts of climate change are another concern.
- Water supply system performance management. The reliability and predictability associated with managing the water supply channel system is of great importance to water supply authorities and their customers.
- Improvement in the water delivery system, especially minimisation of losses and measurement improvements are key issues.
- water trading now allows water to move between areas. Understanding the impacts of trade on the supply and delivery system and ensuring the water market is maximising the economic benefits of water use and minimising disbenefits is very important.
- new developments and enterprises – new developments away from traditional irrigation areas can impact on downstream users and the environment.
Water Quality
- Salt
Forty-five percent of the Shepparton Irrigation
Region is currently underlain by shallow watertables
and this will rise to 60% if nothing is done.
In this scenario, annual losses are expected
to rise from the current $30 M to $47M by
2000 and $90M by 2020.
To address these issues, the Shepparton Irrigation
Region Land and Water Salinity Management
Plan has been endorsed by Government. This
30 year plan is in the fifteenth year of implementation.
In the dryland region some 4500 ha is heavily
salinised. This will ultimately increase to
38 000 ha. in 50 years if nothing is done.
The catchment exports an average
of 180 000 tonne of salt from dryland catchments
to either the River Murray or the irrigation
region. This is expected to increase to 250
000 tonne in 50 years if nothing is done.
- Nutrients
Blue green algal blooms occur
frequently in and downstream of the catchment.
The Goulburn Broken was nominated as Victoria’s
highest priority for nutrient reduction in
the Murray-Darling Basin Commission’s
Algal Management Strategy. An average of 273
tonne of Phosphorus is exported from the catchment
annually. Major nutrient sources include irrigation
drainage, dryland and sewage treatment plants.
The Goulburn Broken Water Quality Strategy
aims to reduce catchment nutrient loads by
65% over 20 years.
- River Restoration
Some 45% of the catchment’s waterways are estimated to
be in very poor, poor or moderate environmental
condition. The Regional Catchment Strategy
aims to improve the condition of 3000km of
stream to good or excellent over 30 years
while maintaining the environmental condition
of streams currently rated good or excellent.
Fishways have been constructed on weirs at a number of sites along the Broken River and Broken Creek.
Water quality in streams in the catchment progressively deteriorates downstream. For summary information about water quantity and quality in the catchment see:
http://www.nre.vic.gov.au/catchment/water/vwrmn/vic/index.htm
- Water allocation
The Bulk Entitlement (BE) Program for the Goulburn and Murray Rivers has been completed. Bulk entitlements specify a finite share of the water resource for a water user at a primary source of harvesting or from the point of extraction. BEs enable the establishment of the water trading framework at two levels: at the bulk level between authorities by trading bulk entitlements, and in rural areas at the retail level by individual irrigators trading temporary and permanent water entitlements.
The MDBC Cap has placed further constraints on the level of diversion from the stream system.
Environmental flows in regulated streams have been specified. In unregulated streams, Stream flow Management Plans are being developed to address water diversion and environmental flow issues.
- Groundwater
Many of the catchment’s groundwater systems are heavily committed, or even overcommitted. Development of groundwater management plans for key systems is underway.
Catchment management arrangements
The Goulburn-Broken Catchment Management Authority leads an integrated approach
to the protection and enhancement of the catchment’s
land and water resources. Working with its catchment
partners, including Goulburn-Murray Water, Goulburn
Valley Water, Department of Sustainability and Environment
and the Department of Primary Industries, the CMA
is implementing its Regional Catchment Strategy.
Where necessary, detailed strategies to address
key issues (eg salinity, water quality, native vegetation)
have been, or are being, developed.
Pat Feehan
Focus Catchment Coordinator (Goulburn Broken Catchment)
0358 335 687
pfeehan@g-mwater.com.au
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