Little Murray River will return to conditions similar to those prior to human intervention, as Goulburn-Murray Water implements work outlined in an environmental flow study.
As part of the Swan Hill Modernisation Project, which includes the lowering of Little Murray Weir, a study was conducted to look at how environmental conditions can be improved, providing benefits that may not have been achieved without the Connections project.
The flow study was led by a committee of representatives from G-MW, DELWP, North Central Catchment Management Authority and customers from along Little Murray River.
Connections environment and water savings manager Ross Plunkett said importantly, Fish Point Weir at the most upstream end of the river would remain open for the majority of the year.
‘‘This will allow water to flow from the Murray River down the Little Murray River that more closely resembles natural conditions and improves water quality,’’ Mr Plunkett said.
‘‘The environmental flow study builds on the automated system’s improved operational arrangements so that flows can be controlled to minimise impacts on native catfish nesting during late spring or early summer.’’
Mr Plunkett said the catfish population in Little Murray River was one of only a few naturally occurring populations of the endangered species in Victoria.
‘‘Catfish require relatively stable water levels,’’ he said.
‘‘Catfish build their nests along the shallow banks of the river and if water levels drop suddenly, catfish can abandon their nests.’’
Endangered species of Murray cod and golden perch are also found in the river.
Removing the current gated structure at Little Murray Weir and providing fish passage will allow accessibility for fish, particularly Murray cod and golden perch, to travel along the full length of the river system, something they cannot currently do with the artificial barrier created by the current infrastructure.
‘‘This arrangement can be achieved whilst still delivering irrigation requirements,’’ Mr Plunkett said.
The key flow outcomes from the environmental flow study will be included in the Torrumbarry Irrigation Area Operational Plan.
The works at both Little Murray Weir and Fish Point Weir are scheduled to take place during the winter works program this year.
The Little Murray anabranch leaves the Murray River near Fish Point and flows north-west, joined by the Loddon River, before it rejoins the Murray near Swan Hill. Little Murray River and the Murray River enclose Pental Island.