Blue-green algae Red Alert for Grahamstown Dam

The Red Alert warning applies only to untreated water in the dam (not drinking water supplied by Hunter Water) and will remain in place until monitoring confirms that the risk is sufficiently diminished.

Grahamstown Dam is a closed drinking water storage operated by Hunter Water. People should prevent pets and livestock from drinking this water. People should avoid recreational activities and any other activity that brings them into contact with this water body 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 are naturally occurring and can reproduce quickly in still or slow-flowing water when there is abundant sunlight and sufficient nutrients.

Visit the Hunter Water website 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