Broken Basin
The Broken River is one of the tributaries of the Goulburn River in north-eastern Victoria. The River Basin named after it also includes the catchment of Broken Creek which diverges from the Broken River just west of Lake Mokoan and flows in a north-westerly direction to the Murray River. The Basin covers 772,386 hectares.
|
Water Source |
Total Water Resource (ML) |
Total Use (ML) |
|
Surface Water |
257,500 |
43,300 |
|
Groundwater |
not available |
not available |
|
Recycled Water |
630 |
330 |
Land and Stream Network
The Basin contains two connected stream networks, that of the Broken River in the southern half and the Broken Creek in the north.
In the far south of the Basin, the Broken River flows westward from its sources in the deeply dissected Tolmie Highlands, then swings to the north near Mt Strathbogie before entering Lake Nillahcootie. The Broken River continues north through undulating farmland towards Benalla and takes in the waters of Moonee, Blind, Holland and Ryans Creeks. Near the junction of the outlet channel from Lake Mokoan, the Broken River swings to the west and overflows to the effluent Broken Creek. It then continues on a westward course across the riverine plain and joins the Goulburn River just south of Shepparton.
Broken Creek flows north through a swampy area, then swings to the west and takes in the waters of Boosey Creek at Katamatite. It meanders westward past Nathalia and joins the Murray River upstream from Barmah.
Rainfall and Surface HydrologyThe average annual rainfall is highest at Mt Strathbogie and in the Tolmie Highlands in the south of the Basin. Above approximately 750 m light snowfalls are fairly regular in winter. From the higher plateaux, mean annual rainfall decreases to about 55% of that at Mt Strathbogie on the Benalla Plain. Rainfall generally continues to decrease northward. Across the far northern section, rainfall generally increase from the west to the east. Reliability of rainfall varies notably over the Basin, being greatest in the elevated areas of high water production, such as on the Tolmie Highlands, and lowest on the plains. Generally in the plains region, summer is hot and winter mild. Streamflow within the Broken River Basin is extremely variable over the seasons of the year, and between years. The three months July to September account for over half of average annual flow.
GroundwaterFor the southern portion of the Basin, in the highlands, shallow aquifers occur in the Palaeozoic basement rocks of folded sediments, metamorphic and granite, whereas in the northern portion of the Basin, in the riverine plain, the shallow aquifer is a complex network of shoestring sands of the Shepparton Formation. The deep aquifer system is restricted to the north of the Basin in the buried sand sheet of the Calivil/Renmark Aquifer.
Groundwater quality varies throughout the Basin, as illustrated in the groundwater quality map. Divertible resources lie mostly in the far north and the south of the Basin and in these areas the quality is good. The minor resources in the Basin are generally located in the central region and quality is generally brackish. The total groundwater resources were ... ML.
Land UseMost of the Basin has been cleared for agriculture which supports grazing in the south, and mixed cereal and livestock farming in the central region. A large part of the northern section of the Basin is within the Goulburn-Murray Irrigation District, with irrigation for fruit growing, dairying and livestock production.
The only extensive forest areas remaining are in the steeper country in the south, the Warby Ranges to the east of Lake Mokoan, and in the Barmah Stare Forests along the Murray. The forested areas are generally not intensively managed for timber production except for limited areas in higher rainfall regions.
Water UseTotal average water use in the Basin is 801,520 ML, of which only about 8 percent are drawn by private diverters from the Basin's own resources, arising about equally from surface and groundwater. The remainder is supplied to customers in the Shepparton and Murray Valley Irrigation areas which form part of the Goulburn-Murray Irrigation District.
Surface Water QualityWater quality varies from good to poor across the Broken basin. Refer to the DSE River Health website for the latest information.
Broken Water StoragesWithin the Broken River Basin there are two major water storages. In conjunction with Lake Nillahcootie, Lake Mokoan harnesses the flows of the Broken River and its tributaries. Water can be released progressively from these storages to supplement flows in the Lower Broken River, and vial the Lower Goulburn River, in the Murray River.
REFERENCES
http://audit.deh.gov.au/ANRA/water/water_frame.cfm?region_type=VIC®ion_code=404&info=resources
