During times of low flows, saline water can pool in lower sections of the Campaspe, from Rochester to where it meets the Murray at Echuca.
The more saline water table can interact with the river, causing dense salty pools that are low in dissolved oxygen.
This low oxygenated water diminishes habitat and forces fish into shallower and warmer parts of the river, making them easier prey.
“Flushing these areas in summer is key to protecting the health of the river,” North Central Catchment Management Authority environmental flows project manager Darren White said.
“For the past five or so years, irrigation water has delivered the flush as it moves down the Campaspe and into the Murray River.
“But this year, with lower irrigation water deliveries through the Campaspe, the flush will be managed with water for the environment.
“The salinity levels have begun to cause potential water quality issues in the lower reach in the past few weeks, so the time to act is now.”
Up to 950Ml of water will flow down the Campaspe for about six days, in late January and early February.
The flow will also provide a boost for native fish such as Murray cod, and the river’s important platypus population.
“The Campaspe is a vital breeding ground for platypus, especially as there are very few populations left in the Murray downstream of Echuca,” Mr White said.
“And cod numbers have been increasing about seven per cent a year since 2016, on the back of good river flow management and revegetation of riverbanks which provides the right conditions for breeding, on top of native fish releases.
“This flow will help them move up and down the river and access different food and habitat.”
The flows are authorised by the Victorian Environmental Water Holder in line with its Seasonal Watering Plan 2021-22.
The plan is available for download from www.vewh.vic.gov.au, with regular watering updates posted on the North Central CMA website www.nccma.vic.gov.au
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