A $100 million deal in South Australia will see water for fodder flow from next week.

The Federal Government has released the details of its Water for Fodder program, after securing a deal with South Australia to ramp up output at its desalination plant.

Adelaide's desalination plant will produce water for the city, freeing up 40 gigalitres for irrigators from December 9.

Another 60 gigalitres is in the pipelines for irrigators after April 1, pending a review of the program.

The Federal Government requires that the water be used to grow fodder or pasture to feed livestock.

“This keeps farmers doing what they do best and provides hope in tough times,” Mr Littleproud said.

Farmers who “have had more than 1 gigalitre available for delivery in the current water year — through carryover or allocations — in the allocation account” are not eligible.

Eligible farmers can apply for 50 megalitres per access licence, with a maximum of two applications.

Compliance and enforcement activities will be used to make sure the water is used for growing fodder and pasture.

“These could be: remote sensoring, onsite visits, audit of evidence such as metering records, allocation account statements for the Allocation Account and any other water allocation accounts held by the Applicant, invoices, photographs and farm surveys,” the guidelines say.

The $100 million deal is expected to produce up to 120,000 tonnes of fodder for livestock.