Environmental watering in the Edward-Wakool River System 2011-12
Commonwealth environmental water was provided for use in the Edward-Wakool River System during 2011-12 for the watering actions listed below.
30 June 2012: These actions have been completed.
5,500 ML of Commonwealth environmental water was delivered in Colligen Creek during November and December 2011. Commonwealth environmental water was delivered in conjunction with water supplied by the New South Wales Government.
The environmental water was used to provide a pulse in river flows over a period of 20 days. The primary objective for this pulse flow was to encourage movement of large bodied native fish such as Murray cod, silver perch and golden perch, and to initiate spawning and recruitment of these species.
Monitoring undertaken by Charles Sturt University has subsequently shown that there were also significant benefits to native small bodied fish, such as carp gudgeons. For a summary of the preliminary results refer to the factsheet: Early results from environmental watering in Colligen Creek.
Wakool River and Colligen Creek
7,500 ML of Commonwealth environmental water was delivered in the Wakool River and Colligen Creek during February and March 2012. The Commonwealth environmental water was delivered in conjunction with water provided by the New South Wales Government.
The objectives of this watering action were to provide opportunities for small-bodied fish, such as Murray-Darling rainbow fish and carp-gudgeons, to access important breeding and feeding habitat and improve the condition of the river and riparian ecosystems.
In the Wakool River the environmental water flows commenced on 14 February 2012 and continued until 6 March 2012 when they were suspended due to heavy rainfall in the region and further upstream in the Murray River catchment.
In Colligen Creek the environmental water flows began on 8 February 2012, and finished on 1 March 2012. This watering action built upon the benefits achieved in the November-December 2011 Colligen Creek environmental water flows referred to above.
The flow was monitored as part of the Edward-Wakool fish monitoring project.
Fish refuge habitat flows – Edward River, Wakool River and Yallakool Creek
39,736 ML of Commonwealth environmental water was delivered to the Edward River, Wakool River and Yallakool Creek durin April and May 2012. Commonwealth environmental water was delivered in conjunction with additional environmental water provided by the New South Wales Government.
The water was used to provide and maintain important refuge habitat for remnant fish populations, particularly Murray cod, from hypoxic blackwater (water containing low levels of oxygen) that can severely impact fish.
Commonwealth environmental water was delivered using Murray Irrigation Limited infrastructure, and continued from water delivered by the Murray-Darling Basin Authority.
This watering action also contributed to the outcomes of environmental watering in the mid-Murray River system (refuge habitat and replenishment flows).
Commonwealth environmental water was made available for use in the mid-Murray River system during autumn 2012 as releases from Hume Dam to target flows of approximately 7.5 GL per day.
The March 2012 floods in the Murrumbidgee catchment resulted in a hypoxic blackwater event (water contained low levels of dissolved oxygen) in the lower Murrumbidgee River. From mid-March through to May, hypoxic blackwater was flowing from the Murrumbidgee into the Murray River, and there were concerns that it may severely impact fish and other aquatic animals.
The objective of this watering action was to provide and maintain refuge habitat in the Murray River for native fish and other aquatic animals, such as Murray cod and Murray crayfish. Releasing environmental water to increase flows down the Murray River, increased the refuge habitat available below the junction with the Murrumbidgee River.
This action complemented pre-releases made by the Murray-Darling Basin Authority from Hume Dam, and Commonwealth environmental watering actions that were undertaken simultaneously in the wider Murray River catchment. An integrated approach was taken to mitigate the negative impacts of hypoxic blackwater from the Murrumbidgee River; Commonwealth environmental water was also delivered in the:
The benefits of this watering action were monitored by the Murray-Darling Freshwater Research Centre. For further information please refer to:
This watering action was managed by the Murray-Darling Basin Authority (River Murray Operations) in cooperation with the New South Wales Office of Environment and Heritage, New South Wales Office of Water, State Water Corporation, Victorian Environmental Water Holder, Goulburn Broken Catchment Management Authority and Goulburn-Murray Water.
Environmental watering in Jimaringle-Cockran Creek
3,000 ML of Commonwealth environmental water was delivered to the Jimaringle-Cockran Creek during March and April 2012. Commonwealth environmental water was delivered in conjunction with 3.2 GL of water supplied by the New South Wales Government.
The environmental water was used to provide a follow up watering following the successful watering of the creek system in autumn 2011. The watering action aimed to improve water quality and continue to improve the health of the vegetation in the system, in particular the aquatic vegetation and fringing river red gum and black box communities.