This region is defined as the Broken Creek downstream of the Boosey Creek confluence, and Nine Mile Creek from Katamatite Township to the Murray River at Barmah Forest, totaling 184 kilometres stretch of waterways.
The creeks and their associated floodplain and wetland habitats support intact grey and yellow box tree and grassy woodland communities and numerous threatened species including Murray cod, golden perch, buloke, bush stone-curlew and brolga. They also contain important cultural heritage sites, provides water for agriculture and urban centres and supports recreational activities such as fishing, camping and bushwalking.
The lower Broken and Nine Mile creeks have been regulated for over 100 years, significantly altering their flow regimes. Under natural conditions, the creeks would have stopped flowing for extended periods during summer and autumn. Today the creeks flows are maintained throughout summer and autumn to supply water for irrigation, domestic and stock use. However, winter flows have been reduced due to water harvesting and are dominated by catchment induced runoff.
Downstream of Nathalia, the Broken Creek has eight shallow weirs managed to provide a near-constant water level for the extraction of irrigation, domestic and stock water by pumping. While the weir pools provide important native fish habitat, their water quality is often poor in summer and autumn.
While all reaches are important, the delivery of environmental water targets the Broken Creek from Nathalia township to the Murray River (reach 3), which supports the most diverse and abundant native fish communities and is often most affected by poor water quality in summer and autumn. However, water delivered to reach 3 also provides benefits to the other upstream reaches (1 and 2).
Lower Broken Creek and Nine Mile Creek priority watering actions include flows to:
- Provide native fish passage through fish ladders positioned on each of the eight weirs along the lower Broken Creek.
- Minimise the accumulation and growth of azolla (a native aquatic plant that floats on the water’s surface), which can reduce dissolved oxygen levels.
- Maintain dissolved oxygen levels above 5 mg/L for native fish and other oxygen dependent aquatic animals.
- Increase native fish habitat during migration and breeding seasons.
Below are the resources available for download regarding proposed watering actions for the Lower Broken Creek:
Any further information regarding proposed watering actions for the Lower Broken Creek can be obtained by contacting the GB CMA.
Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-Eastern Australia
Environmental Water Delivery, Lower Broken Creek, August 2011 v1.0
Photos of the Lower Broken Creek and Nine Mile Creek
To view photos of the Lower Broken Creek and Nine Mile Creek, visit our GB CMA Flickr page by clicking on the image below:
Videos regarding the Goulburn River
To view videos of the Lower Broken Creek and Nine Mile Creek, visit our GB CMA YouTube channel by clicking on the image below: