Temporary water supply change – Rosslynne and Merrimu reservoirs

From June 1, Greater Western Water will temporarily switch the water supply in several towns from local sources to Melbourne’s supply system. 

This change allows us to carry out essential maintenance at our water filtration plants in Rosslynne and Merrimu. Works are scheduled to take six months to complete and we expect to return to local water supply by early November.  

Areas affected 

Switching from Rosslynne Reservoir: 

• Gisborne
• Gisborne South
• New Gisborne
• Macedon
• Mount Macedon
• Riddells Creek 

Switching from Merrimu Reservoir: 

• Bacchus Marsh
• Parwan
• Darley
• Maddingley
• Merrimu

What you might notice 

During the switch, customers in these towns may notice a slight change in the taste or smell of their tap water. This is normal and nothing to be concerned about - the drinking water will continue to meet all Australian standards. 

The difference in taste and smell is due to the different treatment processes used in Melbourne’s water supply compared to local sources. 

Learn more about where your water comes from. 

Protecting our supplies during dry times 

This water supply change also supports our local storages, which have been under pressure following extended dry conditions across much of Victoria since winter 2023. 

While rainfall can boost storages, high demand from our growing population and warmer weather can quickly affect water levels. Connecting to Melbourne’s system helps maintain a reliable supply at all times throughout the year. 

Learn how you can make every drop count to help protect our storages. 

Stay updated about future supply changes 

We email customers to let them know when we’re changing supply systems. To stay informed, please check your contact details.