Issued 16 May 2025
WaterNSW has issued a Red Alert warning for high levels of potentially toxic blue-green algae for the Hunter River upstream Glenbawn Dam, potentially extending downstream to Glenbawn Dam.
This alert has been raised after reports of algal scum at this site on the Hunter River upstream Glenbawn Dam. Algal sampling is taking place at the site to monitor the algal bloom.
The Red Alert warning applies only to untreated water at the identified location and will remain in place until monitoring and test results confirm that the risk is suIficiently diminished. People should avoid consuming untreated water from this waterbody and prevent pets and livestock from drinking this water.
People should avoid recreational activities such as swimming, water skiing, canoeing and any other activity that brings them into contact with this waterbody until the red alert warning is lifted.
Potentially toxic blue-green algae may cause gastroenteritis if consumed, while contact can cause skin and eye irritations. Consumption of water containing algal toxins may cause liver damage and other health problems. Boiling the water does not remove algal toxins.
People who suspect they have been affected by blue-green algae should seek medical advice.
People should not eat mussels or crayfish from red alert warning areas. A precautionary approach to eating fin fish from red alert warning areas is advised. Any fish caught should be cleaned and washed thoroughly in uncontaminated water; the internal organs should not be eaten. Avoiding fishing during a bloom is the best way to minimise risk.
Blue-green algae is naturally occurring and can reproduce quickly in still or slow-flowing water when there is abundant sunlight and suIficient nutrients. Visit the local council or local water utility websites for information about the management of blue-green algae risks in the nearby treated drinking water supplies.
Updates and information about blue-green algae blooms and red level warning areas can be obtained by visiting www.waternsw.com.au/algae or calling 1300 662 077.
