31/7/23: Tweed Shire Council has downgraded the blue-green algae alert at Clarrie Hall Dam from amber to green.

While testing by the NATA-accredited Tweed Laboratory Centre has confirmed algae levels in dam water have decreased, algae species capable of producing toxins continue to be detected.

Council’s Water and Wastewater Operations Manager Brie Jowett said while it was good news the blue-green algae alert had been downgraded, untreated water in Clarrie Hall Dam and its upstream and downstream tributaries might still be harmful to humans and animals.

“Council always takes a cautionary approach with blue-green algae – we continue to advise residents and visitors not to come into contact with dam water, not to eat fish from the dam and to keep animals away,” Mrs Jowett said.

“Never drink untreated dam or river water at any time. Don’t water livestock and other animals with untreated water from the dam and its upstream and downstream tributaries.

“If you come into contact with the algae, rinse it off with fresh water and seek medical advice if symptoms appear.”

Blue-green algae warning signs remain in place at public access points to the dam, alerting the public to the risks.

Affected water appears to have a green paint-like scum on the water, near the edges, or greenish clumps throughout the water. It can have a musty odour.

Council issued a green alert for blue-green algae at the dam in November 2022 and raised the alert to amber in May 2023.

Mrs Jowett said the Tweed’s tap water remained safe.

“Due to our robust water treatment processes, tap water throughout the Tweed remains safe to drink and bathe in,” Mrs Jowett said.

“The processes remove algae and potential toxins, alongside taste and odour compounds, ensuring our tap water continues to be treated to a standard that is well within Australian Drinking Water Guidelines.”

Lab scientists will continue to test untreated dam water twice a week.

Untreated river water that supplies the Tweed’s water treatment plants at Uki, Bray Park and Tyalgum is being tested weekly.