The Murray Darling Basin Authority has announced an investigation into the impact of climate change, especially on the Northern Basin - essentially to check if more water needs to be returned to the environment.
Evidence of changing rainfall patterns could mean water recovery needs to be altered in the Northern Basin, the MDBA has warned.
“Rainfall patterns are changing and these changes will increase pressure on the health of the Basin’s environment, its communities and its economy," MDBA chief executive Philip Glyde said.
"It’s also likely that the management, sharing and delivery of water will become more complex and contested.
Mr Glyde said said the MDBA had launched a discussion paper to kick off the next phase of work to identify where the information gaps were when it comes to the impact of climate change on the Basin.
“That means we need input from the scientific community and other stakeholders to make sure our climate change work program is fit for purpose and will meet the future needs of the Basin’s environment, communities and industries," he said.
We need input from the scientific community and other stakeholders to make sure our climate change work program is fit for purpose.
- Philip Glyde, Murray Darling Basin Authority
“The Basin Plan was drafted as an adaptive plan with climate change in mind.
“The best available science in 2012 said that the climate in the southern Basin was expected to be hotter and drier but it was less conclusive about the expected effect on rainfall in the north."
Meanwhile, new Water Resource Plans to reset the rules in watersheds across the Basin are also being developed between the states, the MDBA and the Commonwealth, which could have significant impacts on irrigators.
What’s more, findings from fish kill inquiries commissioned by both Labor and the federal government found that to prevent future recurrences of mass deaths, more water should be retained for the environment in the Barwon-Darling Catchment.
If the Basin Plan is adapted to these findings, NSW, and Victoria’s commitments to cross-border flows into South Australia will have to be sourced elsewhere - which could see further irrigation reductions in the Southern Basin.
The Water Resource Plans would have to be negotiated between the Commonwealth and the states to reflect the new priorities.
Meanwhile Labor has committed to repeal the 1500 gigalitre cap on irrigation buybacks, and to investigate if the overall water recovery volume should be increased.
Federal Water Minister David Littleproud wants to stay the course, and argues benefits from reforms take time to flow through to the environment, especially during drought.
The Basin Plan should be given until its end date of 2024 before it's reassessed, he said.
The most extreme outcome from political upheaval could see NSW, or Victoria, or both, withdraw from the Basin Plan, and SA irrigators may have to return more water to the environment.
