Council worker Ross Murphy puts up a sign informing
residents of the river closure.
Flood-damaged water treatment plants are being blamed for the levels of E. coli in the river.
Mayor Paul Pisasale said testing revealed E. coli was at "hundreds of times above normal levels" in some river sections. He said it could be months before both the Bremer and Brisbane rivers are re-opened, and warned people to stay away from them until further notice.
"This is very serious; these are dangerous waters at the moment," Cr Pisasale said. "There is nothing we can do but just wait for a while and keep taking tests. We'll monitor it very closely."
He said bacterial levels in the Bremer would pose a "significant health risk" and the Brisbane River possible adverse health risks.
Council workers yesterday began erecting signs at all recreational access points to the river warning residents that the Bremer was temporarily closed.
People who irrigate from the river have also been contacted and asked to stop the practice for the time being.
"The only people who have irrigated from the river were a couple of golf courses and some schools, but the ones we have been in touch with to date have not been irrigating as they had lost their pumps in the flood anyway," Cr Pisasale said.
Queensland Urban Utilities Chief Operating Officer Robin Lewis in a statement said 30 Ipswich sewage treatment plants are operating at "average dry-weather conditions" after being damaged in the floods.
Three more – Bundamba, Goodna and Rosewood – are six weeks away from being back in normal operation.
"While all reasonable efforts to restore and remediate creeks and waterways will be taken, Queensland Urban Utilities continues to advise residents and visitors to stay out of local waterways as they may contain debris, chemical waste and sewage," the statement said.
The World Health Organisation said symptoms of E. coli-related diseases include abdominal cramps and diarrhoea, along with fever and vomiting.
Most patients recover within 10 days, but in a small proportion of patients the infection may lead to life-threatening diseases.
The Bremer has a history of poor water health, with the lower reaches of the river having scored an F for fail in the Healthy Waterways report last year, for the third year running.
In September 2009, defence officials from RAAF Base Amberley admitted their site had contaminated a creek which runs into the Bremer River with cancer-causing chemicals.
Their tests discovered cadmium, nickel, mercury and chromium were found to be above the Environmental Protection Agency (EPA) safety levels.
MORE FLOOD STORIES: www.QT.com.au