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The importance of fish friendly flows

The Loddon River flows over the Kerang Weir
5 Oct 2020

When it comes to fish-friendly flows, you don’t get more fantastic than these.

Environmental flows across the lower Loddon River, Serpentine Creek and Pyramid Creek in the past few years have been a boon for native fish populations.

Murray cod and golden perch have thrived on the flows, and the Vulnerable Murray Darling rainbowfish are now turning up in big numbers across the lower Loddon for the first time.

“This is great news and it shows that water for the environment is working,” North Central Catchment Management Authority (CMA) Program Delivery Executive Manager Rachel Murphy said.

“If you’re a fish, you’re loving life in the Loddon system at the moment. And anglers probably are, too.”

These fantastic fish-friendly flows will continue over the coming weeks, with water targeting the Loddon from the Loddon to Kerang weirs, Serpentine Creek and Pyramid Creek.

But there’s more to these flows than just creating a fish frenzy.

“Environmental water managers are concerned about toxic blackwater this summer, so we’re doing our best to try to mitigate against it,” Ms Murphy said,.

“During major floods, when very high levels of organic matter enter the river, oxygen can be consumed faster than it’s replenished, and oxygen can drop to dangerously low levels that are harmful to fish.

“The big danger is in summer, so these flows down the Loddon in October will wash the leaf litter away while the weather is still relatively cool.

“That means there’ll be less leaf litter around if we get a series of big summer storms and floods, reducing the risk of a toxic blackwater event.

“If we had more natural floods, or more water in the rivers at the right time of year, this wouldn’t be such as big as a concern. But by regulating the rivers, and with climate change having an impact, this is one of the few options we have.”

The flows are also part of the North Central CMA’s Native Fish Recovery Plan which has as one of its goals a plan to create a world-class Murray cod fishery in the lower Loddon and Gunbower region.

The flows are authorised by the Victorian Environmental Water Holder in line with its Seasonal Watering Plan 2020-21, which is available for download from, with regular watering updates posted here.