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

Map of algal alerts in New South Wales

Recreational 'red alert' algal status report: updated 21 October 2014

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 No recent data Media release, signs erected, continued surveillance by Byron Shire Council
North Coast Malpas Reservoir, Armidale Potable, recreation, stock and domestic Steady Media release, warning signs erected by Armidale Dumaresq Council
Hunter Walka Waterworks Lagoon, Maitland Visual amenity No recent data Media release, signs erected, continued surveillance by Maitland City Council
Metropolitan / South Coast Duck Pond, Centennial Park Visual amenity Steady Signs erected, continued surveillance by Centennial Park Trust
Sunraysia Darling River at Tapio Recreation, stock and domestic Steady Continued surveillance by Office of Water

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


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.


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.


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).

Managing algal blooms

The NSW Office of Water oversees the algal risk management framework for fresh and marine waters and has a co-ordination or knowledge broker role that includes co-ordinating the State Algal Advisory Group (SAAG) and the Technical Advisory Group (TAG), as well as the Regional Algal Co-ordinating Committees (RACC).

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 New South Wales.

The Office of Water's responsibilities in algal management are:

  • to provide RACC, SAAG and TAG co-ordination
  • to take a lead role in managing the risk of algal blooms in fresh waters by coordinating algal monitoring, management and public information (media and web based information) in surface waterways and storages where no other management organisation has a role
  • to liaise with other agencies affected by the algal bloom in order that an integrated risk management approach is taken
  • to perform a knowledge broker role and facilitate communication between regional stakeholders and the State body responsible for algal management and provide regular updates of algal management resource material
  • to identify knowledge gaps and encourage scientific research to provide new information to enhance algal management
  • to co-ordinate and manage regular algal information on behalf of stakeholders and ensure that water users and other stakeholders are informed

In 2013, the Office of Water prepared the Draft: Algal Risk Management Sub-Plan for endorsement by the State Emergency Management Committee in 2014.

The purpose of the draft plan is to provide the framework for a whole-of-government approach to algal risk management in order to minimise the impact of harmful algal blooms in water bodies in NSW.

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:

An analysis of cyanobacterial bloom occurrence in Missisquoi Bay (Québec, Canada)

Cyanobacterial (blue-green algae) are a water quality problem common to many parts of the world, including New South Wales and Quebec, Canada. In 2009 Dr Lee Bowling, Principal Limnologist and State Algal Coordinator in the NSW Office of Water visited Quebec on an Australian Academy of Science travel grant to study cyanobacterial problems and their management there. Since then he has worked in collaboration with colleagues from Quebec to examine cyanobacterial blooms in Missisquoi Bay, one Quebec water body frequently impacted by severe blooms. The outcomes of this work are provided in this report, which enhances the ecological understanding of cyanobacterial bloom occurrence and is relevant to bloom management both in NSW and Quebec.