December 2024: Chemical, Water Quality and Macroinvertebrate Analysis

Alison Loxton
Jan 29
2 min read

Hi everyone,

Please find attached the results of our Water Quality Monitoring Program for December, 2024. I thank Helen and Ross and Brian for their valued and voluntary assistance in this program.

Over the month of December we experienced periods of heavy rainfall which greatly affected the results and also stream health. In my backyard we had in excess of 270mm of rainfall; others would have had more or less.

Some notes of explanation may assist:

Water temperature – you will note that this is one of the hotter months and that all readings are taken in the morning, some as early as 8am. This means that at midday the temperatures are several degrees higher. From experience, water temperatures in excess of 30 degrees over several days, combined with excessive nutrients, will produce Cyanotoxic Bloom, which adversely affects water quality and the macroinvertebrates community
pH was average across the range except for Regatta Waters which exceeded 8 on two sites. This is in the alkaline range and is interesting rather than a cause for concern
Turbidity was higher than normal at the Watersports Club and the Coomera River Weir, due to sustained rainfall and suburban runoff (including land development), and this also affected salinity which was almost negligible at the Watersports Club and non-existent at the Weir. Curiously there was high turbidity at one site in Regatta Waters but not so much at others; this site receives runoff with sediment from an adjacent channel when rainfall is heavy.
Phosphates were evident in higher than usual readings in Waterhen Lake (no surprises there) but also in two sites at Regatta waters. Again there is runoff from two channels along that shore as opposed to the other sites which have no homes on the foreshore, and therefore no gardens for fertiliser runoff.
Apart from Waterhen Lake Ammonia Nitrogen was within realistic limits.

All in all a fascinating snapshot of what happened in our waterways in December.

Just a reminder that we will enjoy our first planting together for 2025 on 8th February.

We will commence planting at 8am and will enjoy a catchup at morning tea.

Looking forward to seeing you then.

Kind regards

Steven Gill