Dear Members and Friends,

Zeekoevlei Water Quality

Many of you may have seen the RSA Water Quality Programme on “Carte Blanche” about 2 weeks ago which is very concerning for the country, you would have noticed it was filmed at Zeekoevlei.
Zeekoevlei was the film location only. It was used as a site being a close by and a convenient location, not once was Zeekoevlei Yacht Club mentioned in spite of many other dams and Vleis being mentioned by name.
At the Vlei we have not had a “blue/green algal bloom” which was the gist of what the programme was about for at over 20 years and then it was a single isolated occurrence.
Many years ago the kinds of blue green algal blooms as shown in the programme were noticed at Zeekoevlei when it was extremely hot conditions in the quiet still waters; since the drawdown and other rehabilitation measures were started at Zeekoevlei nearly 20 years ago, these blooms have become increasingly rare, and bloom conditions have not occurred over the last 10 years in the Vlei as a whole.
We are not saying don’t be vigilant!
The water quality is monitored by the City Council Scientific Services Branch every couple of months and the results are sent to us, in fact the latest are herewith. Incidentally this data that shows the Vlei’s faecal coliform counts (that is, the amount of harmful bacteria usually associated with faecal pollution) were very low in this dataset, with the City considering counts of 2000 faecal coliforms per 100 ml of water as “Acceptable” (target levels are < 1000 counts per 100 ml for intermediate contact recreation such as sailing).
A table to help interpret the data.  From the City’s Water Quality Index methodology.

Best wishes,

on behalf of ZVYC,
Anna, Kathryn & Ron