Goulburn Mulwaree Council has closed Pejar Dam, 25km northwest of Goulburn, advising that the area is not safe for swimming, boating and fishing, and that contact with the water may pose a threat to livestock and pets.
High levels of potentially toxic cyanobacteria prompted the council to issue a red alert warning to recreational users after standard monitoring tests for blue-green algae showed potentially dangerous levels in the dam water.
Stock and domestic users downstream on the Wollondilly River are also advised to avoid extracting water from the river or watering stock where blue-green algae levels are suspected to be high.
A red alert warning indicates people should not undertake recreational activities – such as swimming, using watercraft and other water-based actions – where they may come into direct contact with water. Such contact may also pose a threat to livestock and pets.
People who believe they may have been affected by blue-green algae are advised to seek medical advice.
Goulburn Mulwaree Council utilities director Marina Hollands reassured the community that drinking and using the domestic water supply is safe.
“We are not currently drawing water from Pejar Dam, so Goulburn’s town water supply remains unaffected and completely safe to drink or use,” said Ms Hollands. “As usual, we undertake rigorous testing before and after filtration at the Goulburn Water Filtration Plant, and then distribution occurs throughout the city.”
There are two potentially toxic species of blue-green algae identified by the testing at Pejar Dam, both of which may cause gastroenteritis in humans if consumed, and skin and eye irritations after contact. Blue-green algae usually appears as green paint-like scum near the edges of the water, or as greenish clumps throughout the water, and make it appear dirty, green or discoloured with a strong musty or earthy odour.
Regular monitoring by Goulburn Mulwaree Council will continue and the red alert will be lifted as soon as the high levels of algae reduce.