Counsel assisting the royal commission into the Murray-Darling Basin Plan Richard Beasley says its implementation has been hit by a lack of transparency.
The implementation of the Murray-Darling Basin Plan has been plagued by maladministration with the basin authority totally opposed to transparency, South Australia's royal commission investigating the river system has been told.
Senior counsel assisting the inquiry, Richard Beasley, says the basin plan is transformative legislation but its implementation has been characterised by a lack of attention to the Water Act.
"The implementation of the basin plan has been marred by maladministration," Mr Beasley said in his final submissions on Tuesday.
"By that I mean mismanagement by those in charge and the consequent mismanagement of a huge amount of public funds."
Mr Beasley said every piece of scientific evidence presented to the investigation, which universally pointed to failures in the plan, had gone unchallenged.
He was also critical of the basin authority and other federal government agencies for refusing to allow officials to give evidence and described a decision by the South Australian government to deny commissioner Bret Walker's request for an extension of time as a "great opportunity lost".
Mr Beasley said the implementation of the basin plan continued to have a negative impact on the environment and the economies of the basin states.
"But the state that will suffer the most is the state at the end of the system, South Australia," he said.
The commission was also told that the 450 gigalitres of extra environmental flows, secured largely through SA's lobbying, was "highly unlikely to ever eventuate".
Mr Walker has spent almost a year examining a wide range of issues associated with the basin and the management plan to ensure the future viability of the river system.
He has been particularly concerned with questions of rorting by upstream users.
The commissioner has received more than 150 submissions and taken evidence from more than 70 witnesses.
His investigation has also travelled across the basin to hear from local communities.
Mr Walker is due to hand his final report to the state government in February next year.
The inquiry was established by SA's previous Labor government ahead of the March state election after there were widespread reports of water theft by users in upstream states.