The algal alerts reported on this web page are for recreational water use by the general public. Algal blooms can cause waters to be unsafe for recreation in both freshwater and marine water environments. Algal alerts are issued by Regional Algal Coordinating Committees (RACCs) who are responsible for local management of algal blooms.
For information on current recreational alerts view the status reports on this page, call the NSW algae hotline on 1800 999 457, or view the RACC media releases.
Latest algal alert reports
The summary report below provides the most recent algal data collated by the RACCs from across NSW. Algal blooms may be present and not reported to the RACCs. Locations identified below were experiencing algal blooms at the date of the report. This report does not contain data from water storages managed by water supply authorities where there is no public access.
NSW Health advises that any domestic use (including drinking) of surface water without appropriate treatment should be avoided at all times.
Map of algal alerts in New South Wales

Recreational 'red alert' algal status report: updated 20 May 2013
The summary below is based on the most recent algal data available from the NSW Office of Water laboratory and other sources.
For the latest information on Myall Lakes, go to the Hunter Regional Algal Coordinating Committee page.
To sort this table alphabetically click on the column heading.
| Coordination area |
Location |
Major use |
Trend |
Management action |
| North Coast |
Baywood Chase Pond, Byron Bay |
Visual amenity, passive recreation, stormwater retention |
Steady |
Signs erected, continued surveillance by Byron Shire Council |
| Hunter |
Walka Waterworks Lagoon, Maitland |
Visual amenity, passive recreation |
Steady |
Media release, signs erected by Maitland City Council, continued surveillance |
| Hunter |
Telarah Lagoon, Maitland |
Visual amenity, passive recreation |
Steady |
Media alert by Maitland City Council, signs erected, continued surveillance |
| Hunter |
Rathluba Lagoon, Maitland |
Visual amenity, stock and domestic, recreation |
Steady |
Media alert, signs erected and continued surveillance by Maitland City Council |
| Hunter |
Wallis Creek, East Maitland |
Visual amenity, stock and domestic |
Decreasing |
Media release, signs erected by Office of Water, continued surveillance |
| Metropolitan/South Coast |
Yarramundi Lagoon (Agnes Banks) |
Visual amenity, stock and domestic |
Decreasing |
Continued surveillance - little public access |
| Metropolitan/South Coast |
Duck Pond, Little Kensington Pond, Centennial Park |
Visual amenity |
Steady |
Signs erected by Centennial Park and Moore Park Trust, continued surveillance |
| Barwon |
Lake Inverell |
Visual amenity |
Steady |
Signs erected, continued surveillance by NSW Office of Water |
| Central West |
Ben Chifley Reservoir |
Recreation |
New |
Media report, continued surveilalnce by Bathurst City Council |
| Central West |
Lake Forbes |
Recreation,
visual amenity |
Steady |
Media release, signs erected by Forbes Shire Council |
| Murrumbidgee |
Yanga Lake |
Recreation, stock and domestic |
Steady |
Media release, signs erected, continued surveillance by National Parks and Wildlife Service |
Red alerts are declared where algal cell numbers exceed the triggers identified in the Guidelines for Managing Risk in Recreational Waters released by the National Health and Medical Research Council.
All blue green algae 'blooms' should be considered as potentially toxic to humans and animals, and the water should not be used for potable water supply (without prior treatment), stock watering, or for recreation. NSW Health advises that any domestic use (including drinking) of surface water without treatment should be avoided at all times.
Alert level definitions
Red
These alert levels represent 'bloom' conditions. The water will appear green and may have strong, musty or organically polluted odours. Blue-green algae may be visible as clumps or as scums. The 'blooms' should be considered to be toxic to humans and animals, and the water should not be used for potable water supply (without prior treatment), stock watering, or for recreation.
Amber
Blue-green algae may be multiplying in numbers. 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. The water remains suitable for recreational use.
Green
Blue-green algae are first detected in the water at low amounts, possibly signalling the early stages of the development of a bloom. At these concentrations, the blue-green algae do not pose a threat to recreational, stock or domestic use.
Information for water utilities
A new alerts level framework for raw waters used as a source for potable supply is available at Water Quality Research Australia (PDF 2.7 MB).
Algal management
The NSW Algal Management Strategy is administered by the NSW State Algal Advisory Group and the nine regional algal coordinating committees.
The State Algal Advisory Group provides the over arching policy advice and framework for the management of fresh water and marine blooms. Membership of the State Algal Advisory Group is made up of the relevant NSW State agencies, NSW local government and the Murray Darling Basin Authority.
While each member is responsible for a specific area of management and technical information, the NSW Office of Water is the lead agency for water management in NSW and coordinates both the State Algal Advisory Group and the Regional Algal Coordinating Committees.
Conferences and reports
Study to determine cyanobacterial presence using a YSI fluorometer
A Yellow Springs Instruments water quality sonde was used for the detection of phycocyanin and chlorophyll-a along the Murray and Lower Darling Rivers during 2008-2009. This examined whether the in-situ quantification of phycocyanin by fluorometry could be used to determine the abundance of cyanobacteria. This study found that in-situ phycocyanin fluorometry could be adopted as a tool for cyanobacterial management provided that the equipment used has a comparable performance to YSI and that it not be used in turbid water.
Scientific Visits to North America program
Dr Lee Bowling, Principal Limnologist and State Algal Coordinator in the Environmental Evaluation and Performance Branch of the NSW Office of Water was awarded an international travel grant under the Australian Academy of Science's Scientific Visits to North America program to study developments in cyanobacterial (blue-green algal) management in Quebec, Canada during September 2009.
Read Dr Bowling's report on his visit, including the activities undertaken and the outcomes gained, below:
National Cyanobacterial Workshop 2009
The National Cyanobacterial Workshop organised by the NSW Office of Water took place on 12 and 13 August 2009 at Parramatta, with around 110 attendees representing water management organisations, government agencies and research groups from all States and Territories. The workshop was sponsored by the NSW Office of Water, the Sydney Catchment Authority and Water Quality Research Australia. Presentations were delivered by 33 speakers who gave updates on recent events and issues, current research, and monitoring, testing and treatment.