Blue-Green Algae

Hunter Water routinely monitors blue-green algae concentrations (also known as Cyanobacteria) in drinking water sources at Grahamstown Dam and Chichester Dam, as well as river off-takes on the Williams, Allyn and Paterson Rivers.

Blue-green algae are a natural part of aquatic ecosystems, however, under certain conditions these organisms can grow prolifically causing a "bloom".  These blooms can affect water quality and reduce the overall amenity of the water body.

Further information on algal blooms and their effects can be located by visiting NSW Government Algal Information.

Hunter Water manages blue-green algae blooms in accordance with the Australian Drinking Water Guidelines (2011) to mitigate potential risks to the community. 

Hunter Water shares all information including monitoring data with the Hunter Regional Algal Coordinating Committee which oversees the control plans of all NSW water authorities when dealing with blue-green algae.

In the event of blue-green algae outbreak occurring on a Hunter Water site, Hunter Water notifies the public by erecting warning signs at affected locations.

For information on blue-green algae control plans at all other locations in the Hunter region, please refer to algal alerts at the