Blue-green algae amber alert at Clarrie Hall Dam

07 January 2021

Tweed Shire drinking water not affected

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

Currently the Tweed’s reticulated water supply is being drawn from the Tweed River at Bray Park Weir.

The river flow over Bray Park Weir is healthy, minimising the likelihood of a potential algae alert for the weir at this time.

Upstream at Uki, there is a green alert for blue-green algae at the river where the raw water is drawn for treatment to supply that village.

Council’s reticulated water supply remains safe to drink as its water treatment processes remove any potential toxin, together with any taste and odour compounds from blue-green algae.

The amber alert for Clarrie Hall Dam means recreational users of the dam should not come into contact with the water. Also, the water in the dam and its upstream and downstream tributaries could potentially be unsafe for livestock.

While the recent heavy rains flushed algal blooms from Bray Park Weir, the increased nutrient load washed into waterbodies, together with current high temperatures, are favouring algal growth within Clarrie Hall Dam, with only a temporary reduction in algal blooms observed.

All blue-green algae should be treated as potentially toxic. As yet, the volumes of algae are not sufficient to allow Council to test for the presence of those genes that have the ability to produce toxin.

Council will increase testing to twice a week within Clarrie Hall Dam to monitor the algal blooms. Monitoring at other sites will continue weekly.

Signs have been placed at the dam wall and Crams Farm to warn the public.

Blue-green algae occur naturally and can reproduce quickly in favourable conditions.

Affected water appears to have a green paint-like scum, 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.

For the latest, visit Council's website at www.tweed.nsw.gov.au/WaterAndWastewater