Western Plains residents are being advised to keep a close eye on water in the Macquarie River this week as WaterNSW has issued a Red Alert advice for high levels of the potentially toxic blue-green algae.

Water NSW says that visual observations and satellite imagery show high levels of blue-green algae levels “for Burrendong Dam and the Macquarie River downstream of Burrendong Dam extending to and past Dubbo in the Central West region”. 

A statement issued by WaterNSW said “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”.

Blue-green algae are types of bacteria known as Cyanobacteria. They normally look green and sometimes may turn bluish when dying.

A ‘bloom’ of algae offers where it discolors the water, produces unsavory odors, impacts fish population and reduces water quality.

The often highly toxic algae can cause gastroenteritis, skin and eye irritations, liver damage and other health problems.

“The red alert warning applies only to untreated water at the identified locations 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,” WaterNSW said.

“People who suspect they have been affected by blue-green algae should seek medical advice.”

The Macquarie River is an attraction at Narromine and Trangie. IMAGE: https://narromineregion.com.au/river-activities

According to the CSIRO blue-green algae may come to dominate a water body when water is still and weather is warm. The CSIRO says blue-green algae will often occur when cold and warm layers of water in a river or dam do not mix together.

The CSIRO warns that blue-green algae has been known to kill livestock.

It also says when the algae decomposes it can reduce oxygen in the water and thereby kill fish.

“Boiling the water does not remove algal toxins,” said WaterNSW. 

“People should not eat mussels or crayfish from red alert warning areas...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.”

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