Environment Victoria's Doomed Without a Drink report claims the state government's opposition to commonwealth water purchases has been a major roadblock to delivering water to basin rivers and wetlands.
Birds, fish, invertebrates, frogs and flora make up the 140 Victorian species considered at risk in the basin system.
Professor Jamie Eittock, of Australian National University's Fenner School of Environment and Society, said the report shows how many species were at risk because of insufficient environmental water flows.
"The report really highlights how urgent it is that the basin plan is implemented in full and, in particular, for Victoria," Prof Eittock told AAP.
"This means more water needs to be returned to the rivers and (Victorian and federal) governments need to accelerate programs to ensure that water can get out of the river channel and onto the flood-plain wetlands."
Prof Eittock said a Victorian government policy of no over-bank water flows was effectively drying flood-plain forests and other wetlands.
"The second thing is calling on the two governments to collaborate to reach agreement with the landowners who live along the riverbanks in order to allow the environmental water to spill out safely from the river channels and get out on to the red gum forests, the billabongs, the lakes where so many of these endangered forests for fauna live," he said.
Such agreements would involve funding the relocation or raising of infrastructure that would be affected by more environmental flows, Prof Eittock said.
Environment Victoria chief executive Jono La Nauze said key decisions would be made in the next month before a Murray-Darling Ministerial Council meeting.
"Threatened species need real water returned to the rivers and wetlands where they live, and the most straightforward and effective way to do that is buying it from irrigators," Mr La Nauze said.
"If the Victorian government is serious about bringing these animals and plants back from the brink of extinction, they need to revise their position on the Murray-Darling Basin Plan to allow the Commonwealth to purchase more water for the environment."
In a statement, a Victorian government spokeswoman said securing environmental outcomes under the basin plan would require more than just adding water.
"Victoria remains focused on delivering the basin plan, as agreed, with positive outcomes for the environment, communities and regional economies across the entire basin including the Darling River," she said.
"That's why we're working with the Commonwealth to extend the basin plan deadline to ensure Victoria's environmental projects can be completed and deliver 95 per cent of our water recovery target without harming communities."
Federal Water Minister Tanya Plibersek last week flagged significant changes to the plan were likely after requesting advice from the Murray-Darling Basin Authority on the prospect of reaching its water recovery targets by the legislated deadline of June 2024.