Prime Minister Kevin Rudd said today's report - the latest in a long line predicting a bleak future - was further evidence of the urgent need to act now on climate change.

Mr Rudd and Minister for Climate Change Penny Wong visited the Hume Dam on the Murray River near Albury, NSW, following the CSIRO's release of the Murray River Sustainable Yields Report.

Hume Dam is currently at 17pc of capacity, with inflows to the Murray for June this year the lowest ever at just one-sixth of the long-term average.

The new report shows that between 1997 and 2006, inflows to the Murray River were lower than the 'best estimate' (most likely) climate change scenario for 2030 - indicating the impacts of climate change are taking hold faster than anticipated.

Under the worst case scenario set out in the modelling, flows to the Lower Lakes at the mouth of the Murray would fall by 69pc by 2030.

"Tackling the problems in the Murray Darling Basin requires serious action on climate change," Mr Rudd said.

"We're moving to tackle climate change with a new scheme to reduce the carbon pollution that causes climate change.

"The situation in the Murray Darling Basin demonstrates that doing nothing on climate change is not an option."

The Federal Government has committed $3.7 billion to Murray Darling Basin projects as part of the $12.9 billion Water for the Future plan.

The effects of neglect, mismanagement and over-allocation on the Murray River are also highlighted in the report.

CSRIO estimates that water extraction along the Murray has reduced the total end-of-system flow by 61pc.

Flow at the Murray mouth now ceases 40pc of the time, compared to 1pc estimated in the absence of development.

"We've had years of neglect and over-allocation in the Murray Darling Basin," Senator Wong said.

"Addressing over-allocation by purchasing water entitlements is a key priority."

Today’s report forms part of the CSIRO Murray-Darling Basin Sustainable Yields project being undertaken on behalf of the Australian Government and the Murray-Darling Basin states.

The project looks at the impacts of climate change and land use change across the Basin's 18 regions.

A final report pulling together the findings of all 18 sub catchment reports will be released by CSIRO in the coming months.

* More information about the CSIRO Murray-Darling Basin Sustainable Yields project can be found at www.environment.gov.au/water/mdb/ yields.html