Drinking water quality updates

Update: Friday 13 April 2018

Wannon Water is currently experiencing some seasonal algae in the raw water storages that supply Terang and Warrnambool. The drinking water supplied to customers is perfectly safe to drink but some customers may temporarily notice an earthy taste or odour.

This is not uncommon at this time of year as algae thrives in warm, dry conditions. Similar events occurred within the Warrnambool catchment last month, and are occurring at a number of other locations across Victoria at present.


We are actively working to minimise the algal issues through several measures, including changing the source of water and making some minor adjustments to the treatment process.

It's important to note that the issue at Terang is not related to the Cobrico peat fire, which is burning nearby. We can assure customers that no contamination event has occurred at Ewens Hill.

The algae is a naturally occurring condition within some of our raw water storages under certain seasonal conditions.

We apologise for any inconvenience. If customers have any ongoing concerns, please contact us.

Algae Information

Many factors may contribute to water taste, smell and odour problems. The significant factors are algae and chlorine.

Algae often grow in water storages particularly over the hotter summer months. As the bloom recedes and the algae die off they will release chemical substances into the water that may cause a disagreeable taste and odour.

Wannon Water controls potential algae problems by adopting the following management approaches:

  • Algae prevention: Wannon Water regularly monitors water storages for the presence of algae. If algae are detected in high numbers, if possible, the affected water storage will be taken off line.
  • Water treatment: Conventional water treatment plants, like the plant serving Warrnambool, Hamilton, Camperdown, Cobden, Terang, Balmoral, Glenthompson, Casterton and Simpson treat water by a filtering process that will remove the majority of sediments and some taste and odour compounds.
  • Water testing: Monitoring and testing is conducted to assess the taste, colour and appearance of water.
    • Physical parameters such as pH, turbidity, hardness, alkalinity and colour of water are measured
    • Chemical monitoring occurs to identify chemicals from the source water, which can also affect the aesthetic properties of water. 
    • Algae monitoring - algae can impact significantly on taste and odour.

For further information about drinking water and the treatment process click here.