Wasting no time to use their positions of power in the new Senate after being sworn in yesterday, a bolstered number of Greens, with the support of South Australian Independent Nick Xenophon, instigated the inquiry.

They want to determine how much water is currently in water storages in the Murray Darling Basin and how that water can be moved to the drying Lower Lakes and Coorong, at the very bottom of the Murray Darling system.

But the push for water to be taken from higher up the system will require tens of thousands of additional megalitres to cover the huge losses in transferring that water out of storages and through the system, with evidence suggesting the amount of water actually required is simply not available.

Senator Xenophon and the Greens are on record in recent weeks calling for compulsory acquisitions to buy whatever storage water is available to send to the lakes, taking aim at northern basin irrigators, and cotton farmers in particular.

They have supported Australian Conservation Foundation calls for the purchase of several high-profile irrigation properties on the market in south west Queensland and north west NSW.

Newly appointed Greens Senator for South Australia, Sarah Hanson-Young said the aim of the inquiry was to get enough water down the Murray to save the Lakes before Christmas.

"Australians want to see a unified national effort to save the Coorong wetlands and the Murray River's lower lakes," Senator Hanson-Young said.

"The water is there, all that's missing is the political will."

Senator Hanson-Young said the Senate inquiry would report by September 30, and would identify how much water was available in the system, how the Federal Government could obtain it, how it could be transported down the river, and any barriers to making it happen.

The Opposition is supportive of the move for an inquiry, but negotiated with the Greens to have compulsory acquisition taken out of the terms of reference.

* Extract from a full report in this week's Fairfax weekly rural newspapers.