High flows in Murray River to boost fish population

By Rodney Woods

North Central Catchment Management Authority is making the most of the high flows in the Murray River to provide a boost to the local fish population in Gunbower Creek.

Water for the environment (up to 15000Ml/day downstream of Yarrawonga Weir) will flow down the Murray River in mid to late September as part of the Commonwealth Environmental Water Office's southern spring flows, on top of the existing irrigation flows, to ensure native fish have the water and resources they depend on to feed and breed at this time of year.

North Central CMA environmental water project manager Genevieve Smith said the Murray flows had opened up an opportunity to connect Gunbower Creek with the river at the perfect time of the year.

“A small amount of water from the low-lying Gunbower wetlands will flow back into the Murray when we open the Shillinglaws regulator,” Ms Smith said.

“That will put some much-needed carbon and nutrients into the Murray, which will be perfect fish food.

“On top of that, we will open the Yarran regulator at the Gunbower Creek end, allowing water to flow between the two waterways.

“That will allow fish to migrate between both.”

At the moment, due to barriers to fish movement that currently exist along Gunbower Creek, fish have limited opportunities for movement between the Murray River and Gunbower Creek.

“We are in the process of designing and building a fishway at the Koondrook Weir which will allow native fish to move up into Gunbower Creek from the river; but until that happens, providing connectivity through Yarran Creek is one of the only opportunities for fish to move in and out,” Ms Smith said.

“When fish move from the Murray to Gunbower Creek they help to recolonise the creek and maintain the genetic diversity of the creek fish, supporting more sustainable populations of Murray cod, silver perch and golden perch in particular.

“As the weather warms in spring, it is peak season for fish to be active, so the timing is perfect.

“Yarran Creek will be like a fish highway.”

Water for the environment will be delivered through Yarran Creek with the flows returning to the Murray being reused to support environmental outcomes at downstream sites.