A new CSIRO report will help ensure the delivery of maximum ecological benefits from water allocations in the Murray-Darling Basin (MDB).

Funded by the National Water Commission, the report; Ecological Outcomes of Flow Regimes in the Murray-Darling Basin, provides information that will assist water managers to improve and justify delivery of environmental water to 'icon sites', including wetlands of international significance such as the Macquarie Marshes, Gwydir Wetlands and Narran Lakes.

"It's no secret that the health of the Murray-Darling Basin is in decline," said CSIRO environmental scientist, Ian Overton.

"The Australian Government is investing billions of dollars to turn this around and our research is helping ensure that this is put to best use."

Launching the report at the Ecosystem Response Modelling in the Murray-Darling Basin Conference in Sydney, the Commission's CEO, Ken Matthews, said the problem has been that, as water plans have been drawn up, how much water is needed to provide a given level of environmental protection was not known.

To shed light on this issue, researchers pulled together 577 sets of data to investigate the relationships between watering strategies and the health of vegetation, fish and other biota.

A major outcome from the project was the Murray-Darling Basin Floodplain Inundation Model, which for the first time provides a tool to assess and predict changes in floodplain habitat, wetland connectivity and ecosystem health in response to flooding regimes.

"Initial model outputs show that only 25 per cent of the Basin floodplain has been inundated to some extent in the past nine years," Mr Overton said.

"This highlights that the recent period of dry conditions has had serious implications across a significant portion of the floodplain."

Water managers can use the information to improve the planning and delivery of watering regimes and flow management strategies, ensuring water flows can be tailored to maximise environmental outcomes.

The research was part of a National Water Commission initiative funded through the Raising National Water Standards Program.