SOUTH Australian Murray River irrigators will have greater certainty in planning their year thanks to a lift in water allocations.

A 21 per cent initial allocation for the new water year follows permitted offtake of just two per cent of the irrigators' water entitlements in each of the past two years.

SA Environment and Conservation Minister Paul Caica said there was a 95 per cent chance that allocations would reach at least 25 per cent by the end of August.

"This compares with an actual allocation of only 10 per cent at the end of August last year," he said.

Irrigators will also have access to 100 per cent of their approved carry-over volume beginning today.

Despite the good news Mr Caica stressed that River Murray storage levels remained low compared with the long-term averages.