Treated water from the Tweed mains supply is not affected by an amber alert for blue-green algae being issued for Clarrie Hall Dam.
Treated water from the Tweed mains supply is not affected by an amber alert for blue-green algae being issued for Clarrie Hall Dam.

Why Tweed’s water supply is safe despite dam algae warning

TREATED water from the Tweed mains supply is not affected by an amber alert for blue-green algae issued for Clarrie Hall Dam.

The Tweed's reticulated water supply is currently being drawn from the Tweed River without any releases from Clarrie Hall Dam, isolating the amber alert to the dam water.

Water and wastewater operations manager Brie Jowett said the drinking water from the town supply is safe for human consumption because the dam is not spilling water to the river,".

"Our treatment processes are designed to make sure we are able to treat such events when they do naturally occur in the river," she said.

Blue-green algae occur naturally and can reproduce quickly in favourable environmental conditions, such as where there is still or slow-flowing water, abundant sunlight and warm weather as well as sufficient levels of nutrients.

Tweed Shire Council's testing confirmed the blue-green algae species within the dam has the toxin gene (mcyE) responsible for toxin production.

This means it has the ability to produce toxins but at this stage there is no evidence that it has produced toxins.

As a precaution, the council placed signs at the dam wall and Crams Farm to warn the public. These will stay in place while the high levels of blue-green algae remain.

Ms Jowlett said all recreational users of the dam and visitors to Crams Farm and the dam wall are advised to stay away from the water and not to drink it.

The amber alert for Clarrie Hall Dam also means the water in the dam and its upstream and downstream tributaries could potentially be unsafe for livestock.

The council ramped up its water testing regime to monitor the situation at the dam and be prepared for any future blue-green algae outbreak in the river and weir pools.

"Our water laboratory has scientists who lead the field in identifying and testing blue-green algae, so we can assure our customers that they are in safe hands when it comes to our drinking water," Ms Jowlett said.

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

Anyone who thinks they may have been in contact with blue-green algal water is advised to seek medical advice if symptoms appear.