High levels of the bacteria were detected on Friday, with GWMWater issuing a warning that the water was not safe for recreational use.

It was the second time in a fortnight that blue-green algae was detected in Wimmera recreation lake, after a warning was issued for Green Lake in late March.

GWMWater spokesman Andrew Rose said water at Taylors Lake would be tested again on Monday, with results expected by the end of the week.

“The hot weather we’re having will only exasperate the bloom and cells will keep feeding on the nutrients,” Mr Rose said.

“A combination of rain, cooler weather and wind are the elements that help break it up.”

Taylors Lake is a back-up supply for the Wimmera Mallee pipeline, which supplies water to farming properties.

He said the lake had a long history with blue-green algae outbreaks.

“It is pretty common for this time of year and is one of the things that you have to deal with with static water bodies,” he said.

“Most static water bodies have algae present, it’s when conditions are ideal – heat, little rain and a high nutrient load – that things flare up. Cells with keep on feeding until the food source runs out or there’s a change in the weather conditions.”

Warning signs have been positioned at major recreational areas around the lake and will remain in place while the warning is current.

“We recommend that people can continue to use the water body for safe activities, but should avoid skin contact and should not eat fish from the water,” he said.

Those who come into contact with affected water should wash affected skin immediately in clean water.

It is also recommended that people don’t use affected water for cooking, drinking, washing or showering. Boiling the affected water will not make it safe to use.

GWMWater will continue to monitor the water until the outbreak subsides.