Water Quality

WaterTesting1A good indicator of the health of a catchment is the quality of the water that flows out the lower end. With this in mind, our Landcare group has been part of the Streamwatch programme, now with the Greater Sydney Landcare Network, for over 11 years. We regularly test the water at 2 points within the sub-catchment and at the exit point at Crosslands.

Water quality is generally good and has not changed significantly over the last 11 years.


Water Quality brochure

For information on our water quality, what we test for, the sources of pollution and what we can do to help, please see our Clean Waterways  brochure


What have we found?

  • Is the water quality good? Yes, most of the time.
  • Is the quality changing? No deterioration has occurred during the last 8 years, but there is a lot of variation
  • What causes this variation? The biggest factor is when it rained last and how much it rained. Just after rain phosphates from waste water and fertiliser get washed through into the creeks. This is very noticeable upstream nearer houses. On the other hand, salt levels are reduced with rain.
  • What is happening to life in the creeks? We measure dissolved oxygen levels: 80% of upstream and more than 90% of downstream levels are within standards and so able to support life.
  • But what life is there? In recent years we have applied a biological measure counting waterbugs and have found mayflies, stoneflies and caddisflies, a good indicator. However, long-term residents know that the fish which used to inhabit the creeks are no longer there.
  • See these articles on the waterbugs: Tiny Creatures in Our Creeks and Life in Local Waterways

Map of Test Sites.

On a regular basis, testing is completed at 3 fixed sites each month. Other sites in the catchment have also been tested and we are willing to test sites on request of landowners.

Recent Water Test Results

Our Conclusions

Frequency Distribution for Electrical Conductivity, Available Phosphate and Dissolved Oxygen with Flow

Water Quality – Time Series

Raw Data Catchment Exit

Raw Data Mid Catchment


Article in Galston, Glenorie & Hills Rural Community News Mar 16 on Water Testing

Article in Galston, Glenorie & Hills Rural Community News Feb 17 on the Importance of Water

Article in Community News on Citizen Science Water Testing in Glenorie

Article in Galston, Glenorie & Hills Rural Community News Apr 18 on Water Testing