Farmers know best about water use: Turnbull

Prime Minister Turnbull has launched into a defence of farmers and irrigators as he accused Labor of labelling them economic vandals over water.

An Aug. 19, 2004 supplied photo of an aerial view of Cubbie Station, southwest Queensland. Cubbie is considered one of the world's largest private irrigation projects and can store up to 538,800 megalitres of water. (AAP Image/Cubbie Group) Source: CUBBIE GROUP

But there is one government MP concerned about Mr Turnbull's decision to return responsibility for water policy to The Nationals under a new coalition agreement.

Mr Turnbull, who as environment minister was responsible for implementing the Howard government's Murray-Darling Basin in 2007, said now was the time to return water to the agriculture portfolio.

"The ones that understand the water and the country better than anyone are Australia's farmers," the prime minister told parliament on Wednesday.

Labor, on the other hand, did not accept that water had to be sustainably managed by farmers, irrigators, townships and the environment.

"The problem is that they regard every single farmer, every single irrigator as an environmental vandal," Mr Turnbull said.

But Liberal MP Tony Pasin worries the change of responsibility for water will bring repercussions for irrigators in his home state of South Australia.

"The National Party don't have a significant interest in the lower end of the river system that I'm responsible for," he told ABC radio.

Environment Minister Greg Hunt, who hands over responsibility to Agriculture Minister Barnaby Joyce, said water is going to the "best possible pair of hands".

Labor, the Greens and environmental groups are not so sure.

Australia needed someone capable of a sensitive, nuanced balancing act to make sure water was available to the environment as well as farmers and irrigators, Greens MP Adam Bandt said.

"Barnaby Joyce is many things but he's not nuanced and sensitive," he said.

Labor says Australians have every right to question the Nationals thirst for the water portfolio. Water management should be determined by science, opposition agriculture spokesman Joel Fitzgibbon said.

"To do otherwise, I fear will be a disaster for Australian agriculture," he told reporters.

The Australian Conservation Foundation warned that on a big, dry continent such as Australia every community depended on having a healthy, well-watered environment.