Kellyville Water Hardness & Quality Report (2026)

Sydney Water supplies Kellyville, located in The Hills Shire of northwest Sydney, New South Wales. The utility draws water from a vast network of 11 dams and reservoirs within the Greater Sydney catchment, with Warragamba Dam being the primary source. Other significant reservoirs include Prospect, Avon, Cordeaux, and Woronora. Raw water undergoes extensive treatment at major facilities like the Prospect Water Filtration Plant. This plant processes the water through several stages, including coagulation, flocculation, sedimentation, filtration, and disinfection, before it is distributed to millions of residents across metropolitan Sydney.

The Greater Sydney Watershed covers a substantial area of approximately 16,000 square kilometres, primarily consisting of protected catchment areas within the Sydney Basin. Geologically, this region is characterized by Triassic sedimentary rocks, notably the Hawkesbury Sandstone, with underlying Wianamatta Shale and Narrabeen Group sediments. Unlike areas with significant limestone aquifers, the weathering of sandstone and shale in this catchment, combined with acidic soils and peaty moorlands, results in runoff with naturally low concentrations of dissolved minerals. This geological makeup inherently produces soft water.

Because the water is soft, homeowners in Kellyville will notice minimal limescale buildup on household fixtures, kettles, and within pipes, which helps extend the lifespan of appliances like water heaters and dishwashers. You'll also find that soap and detergents lather more easily, meaning less product is needed for cleaning and personal hygiene, and less soap scum will form on skin and hair. There's no need for a water softener, as the water's gentle mineral profile avoids common hard water problems such as spotting on glassware or reduced efficiency in heating systems. Simple cleaning with vinegar is usually sufficient for any minor deposits that might form.