Hotter and drier conditions mean South Australian irrigators are facing reduced allocations for the first time since 2011 but the State Government is considering ramping up Adelaide's desalination operations.

Key points: Irrigators call for desalination to offset allocation cuts

Irrigators call for desalination to offset allocation cuts Increased use would raise production costs

Increased use would raise production costs Cost-benefit study timeframe 'cutting it fine' as drought looms

The Lonsdale desalination plant in Adelaide's south was brought online in October 2011 after the worst drought in the state's recorded history.

It is running at minimum capacity but in July last year SA Water told a Parliamentary Committee it ran at a cost of $40 million a year.

The Government today announced an independent cost-benefit study into a proposal by irrigators to use the desalination plant to offset allocation cuts.

Renmark Irrigation Trust presiding member Peter Duggin said he hoped the report would provide answers for regional communities about water alternatives.

"Common sense tells you if there's the ability to get another 100 gigalitres into the state's economy, then you would be a fool not to at least look at it," he said.

"There's still a great deal of fear in our community and we haven't actually fully recovered from the previous drought.

"[Irrigators] really don't want to be going into the next drought knowing that there's one less tool they have access to, given the positions that most of them are currently in."

SA Environment Minister Ian Hunter said the plant was a critical drought-proofing asset but the costs of increasing production needed to be considered.

"Increasing the production of desalinated water beyond the level required to supply drinking water statewide would make more water available for productive use, but would also increase operating costs for SA Water," he said.

"It's important that any consideration of the increased use of the desalination plant takes into account costs, considers who pays, and aims to maximise overall economic benefit for our state."

The Government said the study's findings would be available in May but Mr Duggin said that date was "cutting it fine" because it appeared SA was going into a drought in the next financial year.

"Clearly, it's going to be difficult for the Minister to give us an allocation that's anywhere between 75 and 100 percent," Mr Duggin said.

"However, the study is being done this year ... so I guess, for that, we should be thankful."