A Powercor spokesman said crews were currently trying to fix the problem.

"From north east Ballarat near Invermay through to Daylesford and Hepburn, there are about 5000 customers affected," he said.

"We had trees come down on powerlines near Clarkes Hill about 3.15pm."

So far today, about 7000 customers have lost power due to the storms.

"The Ballarat egion seems to be the worst hit in the state power-wise," the spokesman said.

Power is expected to return to homes by about 6pm.

Meanwhile, Central Highlands Water have told people to ignore a text warning of a possible breach in Ballarat's drinking water.

The text message has been forwarded around town today telling people heavy rain and floods had damaged a sewerage treatment plant, causing a leak into town drinking water.

A spokeswoman has confirmed the text is merely a hoax.

"There is absolutely to contamination, no breach, no problem," she said.

If people do have concerns they are being urged to call 13 WATER.