The Productivity Commission will put controversial changes to water allocations in the Murray-Darling Basin under the microscope in a fresh inquiry into the troubled plan.
Treasurer Scott Morrison on Wednesday announced the inquiry will look into the effectiveness and implementation of the Murray-Darling Basin Plan.
A proposed change to allocations recently shot down by the Senate has been included in the terms of reference.
Labor, Greens and Nick Xenophon Team senators blocked the move, which would have returned less water to the environment in southern Queensland and northern NSW.
The opposition supported the Greens' disallowance motion, citing concerns over water theft allegations and other compliance issues.
Assistant Agriculture Minister Anne Ruston said she was confident negotiations would get the plan on track after a "political stunt" ahead of the South Australian election on March 17.
"(Opposition water spokesman) Tony Burke has indicated a willingness to want to get this through," Senator Ruston told reporters in Canberra on Wednesday.
"It's very sad it's taken us 100 years to get here and in one night they managed to attempt to blow it up. I remain hopeful we can get it back on track."
Compliance, water trading and other adjustments to the plan opposed by the Greens are also including in the commission's terms of reference.