Dandenong Water Hardness & Quality Report (2026)

South East Water supplies drinking water to Dandenong and surrounding suburbs, including Dandenong East and Dandenong South in the City of Greater Dandenong, Victoria. This utility sources bulk water from Melbourne Water's protected reservoirs, primarily Silvan Reservoir near Mount Dandenong, Sugarloaf Reservoir near Yarra Glen, and Greenvale Reservoir near Somerton. These reservoirs collect rainfall runoff from the Yarra River upper reaches and Maroondah system catchments. Treatment occurs at Melbourne Water facilities, with final disinfection and distribution managed by South East Water for the Dandenong supply zone.

The watershed geology consists of ancient folded sedimentary rocks from the Ordovician period, such as the Silurian-Devonian Darriwilian sandstones and shales. Overlying these are Quaternary alluvial deposits and basalt flows from the Newer Volcanics Province. Because there are no significant limestone aquifers or karst features, the surface runoff yields very soft water with low mineralisation. This is because rainwater interacts briefly with inert siliceous soils and peaty organics rather than calcium-rich strata.

As a result of its soft water character, this supply produces no limescale buildup. This protects appliances like kettles, dishwashers, washing machines, and hot water systems from mineral deposits, extending their operational life without the need for descaling. You'll also find that soap and detergents lather abundantly, meaning you can use less. Some residents might notice their skin and hair feel more hydrated without the dryness often associated with harder water supplies. No water softener is recommended or necessary for this supply.