In December the Corangamite Shire Council advised the public to avoid all physical contact with water at the lake after monitoring detected high levels of the bacteria.

Warning signs around the lake have cautioned the public on the range of adverse health effects potentially caused by contact with the algal blooms, including skin rashes and itchiness, irritation of the eyes, ears and nose, respiratory irritation and asthma-like symptoms.

However, Cr Ruth Gstrein said tests had shown the lake’s particular strain of blue green algae was toxic and even more harmful.

“This strain is quite toxic and can give issues with vomiting and damage to your insides, not just a rash,” Cr Gstrein said.

“There are a number of people using the lake, which is certainly risky in the condition it’s in.

“I’ve seen skiers on the lake and swimmers on a couple of drive-bys — that’s a risk they take with their health.

“I have been told some of the signs have been removed regularly which is dangerous.

“It’s important signs are there so when people are using it they’re aware what the consequences could be.”

The council said it would monitor the bloom throughout summer and notify the public when the lake was safe for use.

With further test samples taken this week, Corangamite mayor Matt Makin said the council was doing its best to keep the community informed of the lake’s condition.

“We are regularly testing the water so we can provide the best advice to the community and we’ll continue to do that,” Cr Makin said.

“All we can do is monitor the conditions and warn people so they can make informed conditions.”

Testing in December indicated bio-volume levels were above the high alert trigger level for recreational bodies of Lake Bullen Merri’s size, specified by Wannon Water’s Blue Green Algae Regional Co-ordination Plan.

People are encouraged to use other lakes in the region for recreational activities including Lake Purrumbete, Deep Lake at Derrinallum and the Curdies River at Boggy Creek.