Blue-green algae Red Alert for Lake Yandel’ora in Mt Annan

Blue-green algae Red Alert for Lake Yandel’ora in Mt Annan

04 December 2019

A Red Alert level warning (high alert) for toxic blue-green algae has been issued for Lake Yandel’ora in Mt Annan, near Camden, south of Sydney. Monitoring by Camden Council has confirmed high levels of potentially toxic alage.

Warning signs have been erected by Camden Council at key locations and will remain in place while high levels of blue-green algae are present. This alert does not affect drinking water supplies in the area.

A Red Alert level warning indicates that people should not undertake recreational activities where they may come into direct contact with the water such as swimming, fishing or watercraft-based activities. Water should not be used for any domestic purposes such as washing or showering, and any contact or ingestion may pose a threat to pets and livestock.

Inhalation of air affected by blue-green algae for any extended period may cause respiratory distress.

People should not eat any freshwater shellfish or crayfish from Red Alert warning areas. Any fish caught should be cleaned and washed thoroughly in uncontaminated water and any internal organs disposed of before consumption.

The species of blue-green algae identified is potentially toxic and may cause gastroenteritis in humans if consumed, and skin and eye irritations after contact. Boiling the water does not remove algal toxins.

Livestock owners and irrigators downstream in Narellan Creek and the Nepean River are advised to routinely check water supplies for blue-green algae and not use any water where surface scum is visible or blue-green algae is suspected. Stock should be removed from the waterway foreshores if any signs of blue green algae are present.

Blue-green algae occur naturally and can reproduce quickly in favourable conditions where there is still or slow-flowing water, abundant sunlight and sufficient nutrient levels. Blue-green algae usually appear as green paint-like scums on the water, near the edges, or as greenish clumps throughout the water. It makes the water appear dirty, green or discoloured and generally has a strong musty or earthy odour.

It is not possible to predict how long the algae will remain at high levels. Camden Council will continue weekly monitoring and the alert will be lifted as soon as the high levels of algae dissipate.

People who believe they may have been affected by blue-green algae are advised to seek medical advice.

Updates about blue-green algae blooms and red level warning areas can be obtained by calling 1800 999 457 or visiting our algae webpage.

Media Contact – Tony Webber – 0428 613 478


Saturday 27 November
2,491,620 ML
2,581,850 ML
9,081 ML
1,298 ML
17,603 ML
Saturday 27 November