May 2025: Chemical, Water Quality and Macroinvertebrate Analysis

Alison Loxton
Jun 24
2 min read

Hi everyone

Please find attached the results of WQM and Chemical Analyses for the month of May, 2025.

In interpreting the results, please find the following:

The water temperatures are heading toward the lowest for the year, which also corresponds with a peak in dissolved oxygen, which in turn is great for stream inhabitants such as macroinvertebrates. As the macroinvertebrates are in turn food for such animals as platypus, there is benefit to all the creatures in a stream.

Note that water exposed to sunlight is warmer than that which is constantly in shade, as would be expected.

This month the pH was generally in the alkaline range ( above 7) which is also great news for macroinvertebrates. The optimal range for drinking water for us humans is a pH of 6 to about 9. Stock animals can tolerate down to 5.5 however much lower and they run into digestion difficulties.
In terms of chemical analyses there were no great surprises, with Waterhen Lake displaying normal readings. This is a positive as water is not flowing over the outlet, so chemicals tend to be more concentrated when water levels are lower.

Regatta Waters has a couple of higher phosphate readings which is most probably due to gardening activities.

Overall, our waterways are in good shape.

On a different note, I recently attended a macroinvertebrate session with a preschool at Sharp Park, Canungra. It was a gathering of wonderful parents (and children of course) who were most interested in the sampling and scoring involved.

A sample was taken and scored, with a higher than normal SIGNAL score. The explanation lay in human alteration of the sample site.

What had happened was that, because it is a very public park, younger people had removed the larger cobbles (rocks) from the stream bed and in the process destroyed habitat for a number of species of caddis fly and also crustaceans. Therefor the SIGNAL score was compromised and skewed in favour of the mayflies which were numerous.

A lesson learnt. Please discourage people of any age from alteration the bed on any waterway.