WaterNSW has issued a Red Alert warning for high levels of potentially toxic blue-green algae at Toonumbar Dam, about 30 km west of Kyogle.

The Red Alert warning applies only to untreated water at the dam.

People should not drink untreated water from Toonumbar Dam and should prevent pets and livestock from drinking the water.

People should avoid recreational activities such as swimming, water skiing, canoeing 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.

Drinking 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 sufficient nutrients.

Updates and information about blue-green algae blooms and red level warning areas can be viewed here.

This information was provided by WaterNSW.

This article appeared on indyNR.com on 12 January 2026.