River Murray irrigators will receive 100 per cent of their water allocations at the start of the next financial year.
As such, irrigators will not be able to carry over water entitlements from previous years.
South Australia is expected to receive its full entitlement of 1850 gigalitres in 2018-19.
Environment and Water Minister David Speirs described the news as a huge win for the environment and for jobs.
“Opening water allocations of 100 per cent provides South Australian irrigators with a degree of certainty and confidence going into the next growing season,” he said.
“Hopefully … our irrigators can grow their businesses and increase the amount of produce they export.”
More exports would mean more jobs, he said.
The state's horticulture industry is already worth $1.25 billion.