South Australia's Environment Department says plans to ensure water flows by dredging the mouth of the River Murray could be in action before the end of the year.

An accumulation of sand in the area has been blamed on low river flows; the current rate of 10,000 megalitres per day is considered too low to shift the build-up.

“There's not... that volume of water available within the River Murray system itself at this point in time to provide for those large scouring flows,” SA Environment Department spokesperson Jarrod Eaton has told the ABC.

“What it means is that we may need to implement mechanical intervention to help assist with maintaining that open Murray mouth.”

Mr Eaton said if significant change in river conditions did not come soon, dredging could start next month.

“Just going back a couple of years ago when we had the high flows at the [SA-Victoria] border, we saw what we call these quite high scouring flows out through the mouth of over 75,000 megalitres a day and you need those high scouring flows to basically get rid of that accumulated sand,” he said.

The Murray-Darling Basin Authority has put aside $4 million to cover the dredging work, but authorities say the cost would be shared equally between the Federal Government and states of Queensland, New South Wales, Victoria and SA.