Tanya Plibersek questions Murray-Darling Basin Plan timeline, flagging deadline extension

The plan is drastically off course, with the government's own department admitting it will be hundreds of gigalitres short of its 605GL water recovery target in 12-months' time.

Water Minister Tanya Plibersek has written to Murray-Darling Basin Authority chair Angus Huston, requesting an honest assessment of "whether the plan has any prospects" of being delivered by the mid-2024 deadline.

The report's findings are due within the next three weeks and will give the federal government justification to extend the plan's deadline.

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For years, agricultural and regional organisations have pointed out the plan would fall dangerously short of its targets, but it's first time the Commonwealth has formally acknowledged the timeline is unlikely.

Ms Plibersek blamed the former government's "decade of denial and delay" and flagged the need for a "major course correction" to deliver the plan in full.

"Over the last year it has become clear that major elements of the plan were either left to drift or actively sabotaged," she said.

"A year from the deadline, this report will give us an honest assessment of the legacy we have received, including whether the Plan can be delivered on time."

READ MORE: Murray-Darling Basin Plan poised to fall short by 2024 deadline

The MDBA has already conceded the plan would be between 190GL and 315GL short, because several water saving projects would not be completed within the next 12 months.

Some of the proposals would need another five to 10 years to come to fruition, a recent report found, while widespread flooding has delayed other projects.

The recovery of 450GL of environmental water is also wildly off track, with only 26GL recovered.

"The plan is too far behind and likely requires significant change to make substantial progress," Ms Plibersek said.

The minister said despite the challenges, the government was still committed to delivering the plan in full.