Water allocation projections have been revised by the South Australian Government this year.

In the last July forecast, there was an even chance that allocations would rise to 52 per cent by the end of November.

That has now been changed to an even chance of a 28 per cent allocation.

The Water Department says the change is based on new data from the Murray-Darling Basin Commission.

The department says if minimum inflows continue into next year, it is likely allocations will stay at 11 per cent until May.