“Ararat Rural City Council cares about the community’s safety so we are asking residents not to have contact with the water or allow their pets to drink from or swim in the lakes,” Ararat Rural City Council chief executive Dr Tim Harrison said.

“The warning signs at Alexandra Lake will stay in place until test results show BGA levels have dropped to acceptable levels. In the meantime, we will continue to monitor the situation."

Warning signs have also been placed at Green Hill Lake for several weeks facing a similar issue.

“We appreciate the community’s patience and we will let residents know when the levels are back to an acceptable level," Dr Harrison said.