Two heavy storms in a month are likely to have little effect on the state's parched dams, with much more rain needed to begin to reverse the impact of months of dry weather, according to the Water Corporation.
Corporation spokesman Phil Kneebone said there needed to be a "significant soaking to soften the catchments to the extent that the rainfall we get will run off into the dams".
He said there would need to be heavy rain at least every three to four days for a month before the dams began to benefit from winter showers.
"If we had a month of consistent rain, we'd be on the way," Mr Kneebone said.
"We do not really expect run-off to any degree until well into June and often July."
He said the only impact on dam levels in the meantime would be the rain that fell directly into them.
"At the moment they remain extremely dry after the extraordinarily low-rainfall 2010 winter, the equal-hottest summer on record and ongoing hot weather with only a couple of wet spells.
"Essentially we need several more bursts of rainfall like overnight and we need them regularly before the streams will start flowing."
Dam levels are currently sitting at 22.5 per cent capacity overall, equating to 140.05 gigalitres, compared with 221.1 gigalitres on this day last year.