Macroinvertebrate surveys

How healthy are our waterways?

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Our Aquatic Monitoring Program provides scientific information on the health of our aquatic ecosystems and helps to guide on-ground management in our catchments.

The monitoring program uses a range of physical, chemical and biological indicators to gauge the health of our waterways. Aquatic macroinvertebrates (water bugs) tend to be the most useful indicators, as:

  • Their presence or absence represents water quality over their entire lifespan, not just at the moment of sampling.
  • They reflect changes in physical habitats, including sediment deposition and altered hydrology.
  • They reflect changes in biological interaction such as the introduction of pest plant and animal species.
  • They are found in almost all water bodies.
  • The type, number and diversity of macroinvertebrate Families present can indicate what stressors may be acting upon a given aquatic system.

Our staff carry out in-house identification of Macroinvertebrates, data analysis and reporting.

Crayfish surveys

There are two native freshwater crayfish species living in creeks throughout the Blue Mountains: 

  • Euastacus spinifer (Giant Spiny Crayfish) and 
  • Euastacus australasiensis (Sydney Crayfish). 

These crayfish may often be confused with the invasive yabbies (Cherax destructor). Yabbies are found in some parts of the Blue Mountains, but they are not native to the region. Unlike the native spiny crayfish, yabbies are smooth shelled, without spines, and generally smaller than the Euastacus species. 

Crayfish surveys have been conducted in 2013, 2016, 2017 and 2018 to monitor crayfish population levels in Jamison Creek and Leura Falls Creek. In 2018 surveys were also conducted in Springwood creek. 

Between 2013 and 2017 there were significant improvements of the Giant Spiny Crayfish (Euastacus spinifer) population levels in Jamison Creek. However the Sydney Crayfish (Euastacus australasiensis) population in Leura Falls Creek declined significantly over that time. Results in 2018 again indicated a reduced population in Leura Falls Creek, although there were signs of improvement in an upper reach site that has been undergoing remediation. Threats to the crayfish include illegal fishing and pesticide contamination, which Council’s Healthy Waterways Team is working to address. 

Download the full reports of the 2016, 2017 and 2018 surveys from 'Related Downloads'.

Recreational Water Quality

During the warmer months, you might be tempted to cool off in a local creek or waterway. But is it safe?  Each week over summer, we test several popular local waterways for bacterial contamination. While it is not possible to provide real-time water quality results, you can use this information as a general guide to water quality at these locations. 

Be aware that water quality can change on any given day and contamination can occur at any time, even during dry weather. If unsure about local water quality conditions, contact Council on 4780 5000.

The results from the 2019-20 recreational water quality monitoring are displayed below:

Waterway/site Recreational water quality grade
Megalong Creek Poor
Yosemite Creek Very Poor
Wentworth Falls Lake Jetty Poor
Wentworth Falls Lake Beach Good
Glenbrook Lagoon Boat Ramp Poor
Glenbrook Lagoon Beach Poor
Jellybean Pool Good

A Good rating suggests the location has generally good microbial water quality and water is considered suitable for swimming most of the time. Swimming should be avoided during and for up to three days following heavy rain. 

A Poor rating suggests the site is susceptible to faecal pollution and bacterial water quality is not always suitable for swimming. During dry weather conditions, ensure the location is free from signs of pollution, such as discoloured water, odour or debris in the water, and avoid swimming at all times during and for up to three days following rainfall. 

A Very Poor rating suggests the location is very susceptible to faecal pollution and bacterial water quality may often be unsuitable for swimming. It is recommended to avoid swimming at these sites. 

Enjoy our waterways safely

Many Blue Mountains waterways are susceptible to faecal pollution (from sewer faults, stormwater pollution and inputs from agricultural animals) and bacterial water quality is not always suitable for swimming. Faecal pollution is more likely during and for up to three days following rain, however, it is possible for contamination to occur at any time, even during dry weather. 

Common ailments associated with swimming in contaminated water are eye, ear, nose and throat infections, skin diseases and gastrointestinal disorders. Following these general rules will help minimise the risk of infection due to contact with contaminated water:

  • Avoid all contact with waterways during and for up to 3 days following rain
  • If considering swimming during dry weather conditions:
    • Understand the catchment area for the waterway and the associated risks of water pollution (look at Google Maps/Earth, a topographic map or ask Council for advice). 
    • Ensure the location is free from signs of pollution such as discoloured water, odour or ‘urban’ debris in the water (such as rubbish, exotic leaves etc).
    • Keep water out of ears, eyes, nose and mouth (i.e. keep head above water); 
    • Avoid water contact with broken skin such as cuts, bites or grazes.
    • Remember that the very young, very old and those with compromised immunity are at greater risk of illness due to contact with poor quality water. 

Report pollution incidents to Council (4780 5000) or the NSW Environment Line (131 555).

Download the full Recreational Water Quality Report 2016 below.