Toowoomba Regional Council has closed Cooby Dam to the public until further notice.
Toowoomba Regional Council Water and Waste General Manager Damian Platts said Council officers had detected high levels of Saxitoxin, which if ingested may cause nausea, vomiting, abdominal pain and possible diarrhea.
"Council will close entry gates to Loveday Cove, and the Cooby Dam wall picnic areas and signage will be put in place indicating the closure of areas to the public until further notice," Mr Platts said.
Mr Platts said the test results meant Council had closed the facility as a safety precaution.
"Council will conduct its regular testing regime to determine when the dam can re-open," Mr Platts said.
"The toxin represents no risk to drinking water supplies as the water treatment, and disinfection process removes them.
"Council monitors the three dams weekly for algae and numerous microbiological parameters including E.coli. We also test chemical parameters such as iron, manganese, alkalinity, hardness, ammonia, nitrate, colour, turbidity and phosphate.
"The treatment process is also closely monitored (daily). When the water leaves the treatment plant, we conduct tests in the distribution system under our Drinking Water Quality Management Plans.
"These plans line up with the Water Supply (Safety and Reliability) Act 2008.
"Even if we are not using a particular dam, but a test shows that levels are too high for primary contact (swimming) or secondary contact (boating) we inform Council's Parks and Recreation Services branch about closing a facility to the public."
"Lake Perseverance and Lake Cressbrook also remain closed to the public."
To view activities open or closed at the dams, please visit www.tr.qld.gov.au/damstatus
