Gunbower Creek will receive an increase in flow this week as consumptive water is used en-route to boost native fish populations.

Water destined for downstream users on the River Murray will be diverted into the National Channel and on to Gunbower Creek, before returning to the River at the Koondrook Spillway.

Up to six billion litres (6GL) of environmental water supplied by The Living Murray program will be used to maximise the ecological benefits of the flow, and to cover losses associated with the water delivery.

The North Central Catchment Management Authority (CMA) is coordinating the water delivery in partnership with the Department of Sustainability and Environment, Goulburn-Murray Water (G-MW) and the Murray-Darling Basin Authority.

“This is a great way to achieve environmental benefits, while limiting the amount of environmental water actually required,” Melanie Tranter, North Central CMA Gunbower Forest project manager said.

“Using consumptive water en-route means that the water works twice. It goes to the customer as well as providing the environment with a boost along the way – it’s a win-win”

The flow will provide a spawning cue for native fish and, combined with the recent inflows to the Murray River, deliver food resources into Gunbower Creek.

“In recent years Gunbower Creek has been operated at low levels as a result of the drought and low irrigation allocations. This has put native fish populations under stress, which is affecting their breeding success,” Ms Tranter said.

“Recent monitoring has shown low numbers of young Golden and Silver Perch coming through the creek, which is threatening the future viability of these populations.”

The flow will be delivered as a series of spring pulses. The first pulse will begin this week and last for about six days.

The second pulse will be delivered in November and will last for approximately 10 days, producing bank-full flows. The timing and volume of water diverted in the second flow will be largely dependant upon irrigation demand throughout the Gunbower Creek system.

“The pulses are designed to create better conditions within the creek to encourage spawning in target fish species, such as Golden and Silver Perch, will lead to a stronger fish population,” explained Ms Tranter.

Goulburn - Murray Water’s Acting Executive Manager Water Resources, Mark Bailey said the second pulse will produce a full spring flow in Gunbower Creek for the first time in five years.

“We will also see considerable flows passing over Koondrook Weir during this flow event,” Dr Bailey said.

“This part of the creek hasn’t seen significant flows for sometime and will greatly benefit from the environmental flow.”

A comprehensive flow gauging program will allow the accurate calculation of water used in the environmental flow.

“The ecological and gauge monitoring being undertaken for this flow will enable us to have a greater understanding of the Gunbower Creek system, assisting the North Central CMA to access more environmental water to deliver events like this in the future,” concluded Ms Tranter.

The Living Murray is a joint initiative funded by the New South Wales, Victorian, South Australian, Australian Capital Territory and the Commonwealth governments, coordinated by the Murray-Darling Basin Authority.

The water, sourced from The Living Murray environmental water entitlements, is set aside specifically for the environment and does not affect water allocations to farmers or town supplies.

For further information please contact: 

Communications Officer, North Central CMA
PO Box 18, Huntly VIC 3551
t: 03 5448 7124
e: info@nccma.vic.gov.au