Environment & Health >> Lake Wyangan & Blue-Green Algae

Lake Wyangan & Blue-Green Algae


Lake Wyangan Blue-Green Algae Alert Level – Current Alert Status - RED

Total Bioviolume of 11.55 mm3/L and Toxic Biovolume of 1.88 mm3/L

Date of most recent sample: 14 January 2020


Watch the clip below to see where ALL THE SEDIMENT AND NUTRIENTS GO WHEN IT RAINS


See table for more information here:

Blue-Green Algae Alert Levels - What do they mean?

No alert

Green Level

Amber Level

Red Level

No restriction No restriction, suveillance mode. Low concentrations, but requiring samples and surveillance.  No restriction. Heightened level of alert, with continued sampling and surveillance.  Restricted. Water is unsuitable for primary contact recreational use. No drinking, no swimming, bathing, boating, water skiing, sailing, kayaking, no sifhing or other direct water contact sports. No animal stock watering. Increased sampling and surveillance. 

* Primary contact recreational use – where the body can be fully immersed and you are in direct contact with the water. There is also the potential to swallow water.

Lake Wyangan & Blue-Green Algae Monitoring

Griffith City Council’s Environment, Health & Sustainability Unit regularly samples, has analysed and monitors the water quality of Lake Wyangan (North) throughout the year for the presence of Blue-Green Algae.

The sample results are then used to raise a Blue-Green Algae Alert Level specifically for Recreational Waters such as Lake Wyangan (North). This Alert Level system is as specified by our regions Murrumbidgee Regional Algae Coordinating Committee (RACC) within its Murrumbidgee Regional Algal Contingency Plan. Further, within this Plan GCC is required to advise NSW Health and the NSW Office of Water of the occurrence of a BG-A Red Alert and to warn the general public that the Lake Wyangan (North) water body is currently unsuitable for recreational use.

Murrumbidgee Regional Algal Co-ordinating Committees (RACC) is a forum of organisations (including Griffith City Council) which aims to manage and minimise algal blooms in the Murrumbidgee region. The Department of Primary Industries – NSW Office of Water is responsible for coordinating the RACCs in New South Wales.

If an algal bloom is detected in the Griffith Local Government Area, the RACC will work with local authorities such as Griffith City Council to control the bloom and any effects it may have on water quality.

About Algae

Blue Green Algae growth is a potential problem in the region’s water bodies due to the slow-moving nature of rivers, channels, dams and lakes and the effects of the ongoing drought. Algal blooms cause problems in several ways – they are unsightly, with an offensive smell; they affect aquatic life; the algae blocks water pumps and other equipment; and they produce chemicals which can irritate the skin. Algal blooms also taint the water, giving it a musty or earthy taste which is very difficult to remove and can make the water undrinkable. Most importantly, some species produce toxins that may be poisonous to animals and humans if they are consumed, inhaled, or even if they touch the skin.

Blue green algal toxins can be colourless, odourless, and can remain present in the water for weeks after the bloom has disappeared. As the toxins cannot be removed by boiling water or other treatments it is often necessary to find an alternative source of water, not just for human consumption, but also for livestock and crops.

Species of blue-green algae may bloom and increase excessively in water when:

  • Nutrient levels, particularly phosphorus and nitrogen, are sufficient to support growth
  • Water is still or there is little turbulence
  • Weather patterns are stable for a long time
  • Weather is warm (although blooms can occur in cooler weather too).
  • Light conditions are suitable

The longer the period of calm weather conditions, the greater the "bloom-forming potential". Such potential exists mostly in slow flowing rivers or in lakes, dams, weirs and reservoirs.

Blooms can persist for several weeks or sometimes months. Cooler, windy weather or increased flow may reduce or stop them fairly quickly.

What should I do if I have noticed an algal bloom?

Firstly, do not go near the water, and keep all animals and people away from the water. Then contact Council's Environmental Health Officer on (02) 6962 8100 or Murrumbidgee Irrigation on (02) 6962 0200 to report it. The RACC will then take the appropriate action.

How do I find out if an algal alert has been issued for an area?

In addition to the Blue-Green Algae Alert Level – Current Alert Status section of this webpage you can alternatively log onto Murrumbidgee RACC to check the area’s algal status, or you can phone the Algal Hotline 1800 999 457. Signs will be erected if a water body is closed due to an algal bloom.

Recreational Water

Recreational water bodies are used for a variety of activities including swimming, fishing, water skiing, and boating. Areas with recreational water bodies nearby can also be used for bushwalking and camping purposes. Recreational water bodies are therefore a valuable community resource.

There can be a number of risks associated with recreational water bodies including physical hazards such as snags and rips, microbial hazards such as faecal contamination from humans and animals; algal blooms; dangerous animals such as snakes; and chemical hazards such as pesticides. Humans can also pose a risk to recreational water bodies by introducing aquatic pests such as alligator weed and carp.

The National Health and Medical Research Council have released Guidelines on managing risk in recreational water and they have identified three categories of recreational activity:

  • Primary contact recreation - where the body can be fully immersed and you are in direct contact with the water. There is also the potential to swallow wate. This includes surfing, water skiing, diving and swimming.
  • Secondary contact recreation - includes activities such as paddling, wading, boating and fishing in which there is direct contact but the chance of swallowing water is unlikely.
  • Passive recreation - is where there is no contact with the water and includes scenic appreciation, walking and picnicking around the water.

It is the aim of local authorities to ensure the water is safe for all categories of recreational activity, and may include water quality monitoring programs, provision of facilities, water safety education and environmental programs.

Please contact Council's Environmental Health Officer on (02) 6962 8100 for more information on recreational water.

Other Links of Interest

Algae Alerts and information for NSW

Strategic algal management for NSW

National Health and Medical Research Council (NHMRC 2008)

BGA and water quality fact sheet

MDBA Algae information

Lake Wyangan Catchment Management Strategy Project

Lake Wyangan and Catchment Management Strategy – Strategy Report June 2017

Lake Wyangan and Catchment Management Strategy – Technical Report June 2017