A number of residents have raised concerns with the NWRA Committee over the presence of algae bloom in the canals. We have reached out to Noosa Council and below is their reply.
Regarding the vegetative mats currently present in some areas of the Noosa waters canals. The issue has been flagged with our infrastructure department who have advised that the salinity pump has recently received some maintenance work and is currently running at capacity. To update, this is not abnormal for this time of year - particularly given the amount of rainfall and vegetative matter that has recently washed into the canals. On many occasions, a yellow-brown foam has been observed in rivers, creeks and canals in many areas across Queensland. Previous scientific examination of these foam like vegetative mats has revealed the presence of vegetable material, such as grass clippings, leaves and twigs been blown or washed into the waterways. Microscopic examination has shown undifferentiated algal, vegetable and diatomaceous debris and some filamentous organisms, namely iron bacteria. The iron bacteria are typically associated with brown fibrous material washed out of storm water systems. These materials sometimes attach to rocks or structures in waterways. Bacterial examination has shown faecal coliform levels to be within the guidelines for recreational water, as described by the National Health and Medical Research Council, namely less than 200 faecal coliforms per 100mL of sample. However, we don’t expect or recommend residents have any primary contact with this water in these conditions. Chemical tests have also shown no increases in ammonia or phosphate concentrations above background levels - indicating that the vegetative mats are not a result of sewage contamination or toxic algal bloom. These vegetative mats will dissipate over time. However, Council will continue to monitor the waterways.
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