23 August 2023
WaterNSW has issued a red alert advisory for high levels of potentially toxic blue-green algae for the Darling River at Tapio.
This 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 sufficiently 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 sufficient 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.
General enquiries – Gerhard Schulz (RACC Coordinator) | Gerhard.Schulz@waternsw.com.au
Alert Definitions for Recreational Waters
Alert Definitions as specified in The National Health and Medical Research Council (NHMRC) Guidelines for Managing Risks in Recreational Water 2008. The use of these guidelines is endorsed by the Scientific Subcommittee of the NSW Algal Advisory Group.
These alert levels represent ‘bloom’ conditions.
- Water will appear green or discoloured and clumps or scums could be visible.
- It can also give off a strong musty or organic odour.
- Algae may be toxic to humans and animals.
- Contact with or use of water from red alert areas should be avoided due to the risk of eye and skin irritation.
- Drinking untreated or boiled water from these supplies can cause stomach upsets.
- Alternative water supplies should be sought or activated carbon treatment employed to remove toxins.
- People should not fish when an algal scum is present.
- Owners should keep dogs away from high alert areas and provide alternative watering points for stock.
Blue-green algae may be multiplying, and the water may have a green tinge and musty or organic taste and odour.
The water should be considered as unsuitable for potable use and alternative supplies or prior treatment of raw water for domestic purposes should be considered.
The water may also be unsuitable for stock watering.
Generally suitable for water sports, however people are advised to exercise caution in these areas, as blue-green algal concentrations can rise to red alert levels quickly under warm, calm weather conditions.
Blue-green algae occur naturally at low numbers.
At these concentrations, algae would not normally be visible, however some species may affect taste and odour of water even at low numbers and does not pose any problems for recreational, stock or household use.