New South Australian Liberal senator Andrew McLachlan has vowed to fight calls to scrap the Murray-Darling Basin Plan.
The state turned federal politician took a thinly veiled swipe at the NSW government during his first speech to parliament in Canberra on Wednesday.
"It is my intention to continue to dedicate myself to the plan's success and resist those naysayers," he told parliament.
"I do not see at this time any viable alternatives to maintaining environmental flows as well as maintaining sustainable farming."
Some irrigators have called for the controversial plan to be paused, while NSW has issued repeated threats to pull out over sending environmental water downstream during drought.
But Senator McLachlan argued common interests across the basin meant there were rights and obligations for all communities relying on the river.
"We are committed to the Murray-Darling Basin Plan and its successful operation," he said.
He described the plan as an example of the real benefits stemming from commonwealth and state cooperation.
"In South Australia we only know too well that an open and healthy river mouth can have a dramatic impact on the health of the river upstream," Senator McLachlan said.
The former South Australian legislative council president also urged the federal government to reject calls to relocate 700 submarine maintenance jobs to Western Australia.
"It is important to all South Australians that we are allowed to make the most of the opportunity with the commitment that South Australia is and will remain the defence state," he said.
"We are grateful but we are also very attentive to ensuring opportunities are not whittled away by others or squandered by ourselves."
On the environment, the moderate Liberal said Australia faced a complex economic transition, backing free markets to manage the changes.
"All the answers and the path ways forward will not magically appear before us as if they were fully formed in the head of Zeus," Senator McLachlan said.
"My vision is this country leads innovations that will gift us new technologies to lower not only emissions, but the cost of energy."
Senator McLachlan replaced conservative Liberal turncoat Cory Bernadi, who retired last year as an independent.
Australian Associated Press