River Murray Minister Karlene Maywald said while there had been flooding in the northern part of the basin, hot and dry conditions in the south has kept water availability low.

"SA's improvement in the MDB Authority's latest water resource assessment is just 10 gigalitres," she said.

"This 10gL must be used to meet our critical human water needs reserve for 2010-11. We now require a further 12gL to reach our target of 201gL for human critical water needs for 2010-11."

Ms Maywald said any floodwaters secured from upstream would only be used for critical issues affecting the River Murray and the Lower Lakes, not for irrigation or town water supplies.

The current volume in Hume, Dartmouth, Menindee Lakes and Lake Victoria is about 2432gL or 26pc of capacity.

This time last year storages were at 2015gL or 21pc capacity.