Published on Tuesday, 16 December 2025 at 1:55:47 PM
With the arrival of hot weather and lower water levels, it is common for recreational dams and weirs across Australia to return positive tests for Naegleria during the summer months. This includes the Drakesbrook Weir and Waroona Dam (Lake Navarino).
There are many types of Naegleria found naturally in the environment, and most of them are harmless. Only Naegleria fowleri is associated with the very rare illness Naegleria meningoencephalitis. Infection remains extremely rare, and almost all recent Australian cases have been linked to untreated private water supplies such as bore water or farm dams.
What this means for our community:
* The likelihood of infection remains very low. There have been only three confirmed cases in Western Australia, and none since 1985.
* The Shire will only notify the community if Naegleria fowleri is confirmed, not when other non-harmful Naegleria species are detected.
* Water quality can vary naturally during summer, and ongoing monitoring will continue.
* Residents should be aware of the general risks associated with swimming in natural, untreated water bodies, not just locally, but anywhere in Australia.
* Natural water bodies are not managed like public swimming pools, so we encourage everyone to enjoy them sensibly, noting that swimming is undertaken at your own risk.
Simple precautions when swimming in natural water bodies:
* Avoid jumping or diving into warm, still water.
* Keep your head above water where possible.
* Avoid stirring up mud or sediment.
* Consider using nose clips to reduce water entering the nasal passage.
Recent retesting of the Drakesbrook Weir has shown that E. coli levels have decreased and are now within an acceptable range, in line with recreational water guidelines.
We’re sharing this information to keep our community informed, not alarmed. The risk remains low, but awareness helps everyone make safe choices when enjoying our waterways this summer.
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