The Victorian state government has announced new permanent trade and operating rules for the Goulburn to Murray River trade, to keep flows lower over summer and autumn, while guarding against irrigators' delivery risk.
Water Minister Lisa Neville said there had been increased pressure on the Murray River and Goulburn River to deliver trade and environmental water, which has led to constant high flows in the Goulburn during summer.
These high flows prevented vegetation growth and fish breeding and caused erosion and bank degradation.
"We are making sure the lower Goulburn River is managed to protect its environmental health and its recreational, community and cultural values while protecting irrigators' access to water" Ms Neville said.
"The new rules will support irrigators by providing sustainable trade opportunities without impacting other water users or damaging the environment."
From July 1, the government will replace interim arrangements with similar long-term trade and operating rules.
In an average year, new trade opportunity will be around 150 gigalitres, an increase from 130 gigalitres under the interim rule, while still allowing for extended low flows in summer.
This is a similar amount of trade to 2020, and more than last year.
Two extreme dry years from 2017 to 2019 saw no trade available from the Murrumbidgee system in New South Wales and no in-flows from the Darling - pushing up demand from the Goulburn River to new levels, causing continuous high flows.
Interim trade rules were put in place for the Goulburn River in 2019 and were extended last year.
Read more: Focus on reducing dairy's methane footprint
Ms Neville said over the past 12 months, further testing has been conducted and consultation with scientists, river operators, Traditional Owners, environmental waterway managers, irrigators and the community to settle on rules for the long term.
She said water would be delivered in a smarter, more sustainable way that respects the environmental, cultural and community values.
Getting the trade rules right for the Goulburn River was part of the important work the government had done to protect existing entitlement holders from increasing delivery risks in the Murray River.
This included working through the Murray Darling Basin Ministerial Council on deliverability issues and limiting any new extractions in the Victorian Lower Murray region.
The permanent rules include an exemption for tagged water use restrictions for the Lower Broken Creek while trade and water use behaviours are monitored over the next four years.
Want to read more stories like this?
Sign up below to receive our e-newsletter delivered fresh to your email in-box twice a week.