Proactive flow to help protect our waterbirds

A proactive water flow onto the Gunbower Forest floodplain is aimed at building resilience in native waterbird populations at a time when they need it most.

The environmental flow will also help bridge the gap between the amount of water that made it onto the floodplain from the recent high Murray River flows, and the amount that should have.  

Following high river flows in mid-July, North Central Catchment Management Authority (CMA) began delivering water to the floodplain’s wetlands before pausing in anticipation of further high flows later in the month.

The environmental flow has now resumed as the highest flows have moved through the system. This time it has an additional focus.

Environmental water on the floodplain provides an opportunity for a positive response from waterbirds, something Arthur Rylah Institute Ornithology Scientist Dr Nyil Khwaja said could help native species battle likely bird flu outbreaks.

“More water on the floodplain at Gunbower increases the chances of waterbirds coming together to nest, and these group-nesting events are important for sustaining their populations,” Dr Khwaja said.

“Many of these species are ones that research suggests are going to be susceptible to H5N1. A successful nesting event would help make their populations be as resilient as possible to the additional threat posed by the virus.

“While we might see some additional mortality of breeding birds in these events due to the virus, we expect any group nesting that happens to be an overall positive for their populations based on the evidence we have.”

North Central Catchment Management Authority (CMA) Chief Executive Officer Brad Drust said recent high Murray flows and wetter conditions have provided an opportunity to do more.

“Without river regulation, recent natural peaks that put water onto the Gunbower floodplain would have been twice as large,” he said.

“There would have been constant overbank flows into the forest from June to August – more than two months.

“That’s why this environmental flow is needed. We can now deliver water to more areas of the forest, help bridge the gap between what should have flowed onto the floodplain and what actually did, and support more breeding and feeding habitat.

“That’s great news for waterbirds, but also for our world-famous redgums and wetlands.”

The flow will enter the forest via the Hipwell Road regulator and channel and will be managed to ensure downstream consumptive users on Gunbower Creek have access to the water they need.

The flow will inundate about 3500 hectares of the forest and wetlands, three quarters of the environmental water footprint and less than 20 per cent of the floodplain.

“Working alongside Mother Nature like this allows us to get great bang for our water buck,” Mr Drust said.

“This is not new or extra water. It is the same amount of water that was planned when the flow began in June.

“Delivering it via the Hipwell Road infrastructure allows us to be efficient and really effective. If we didn’t have this infrastructure on the floodplain, the deficit between what should have been, and what will be, on the forest and in the wetlands would be a lot greater.”

The flows are authorised by VEWH in line with its Seasonal Watering Plan 2026-27, which 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.