Woy Woy Water Hardness & Quality Report (2026)

Central Coast Council supplies the Woy Woy community with water primarily drawn from Mangrove Creek Dam on the Colo River and alluvial groundwater aquifers. Water is treated at facilities like the Warnervale Water Treatment Plant, which serves the region north of Sydney. The Central Coast System adheres to the Australian Drinking Water Guidelines, with testing conducted by NATA-accredited laboratories to ensure quality for residents.

The catchment area is part of the Central Coast's Hawkesbury-Nepean watershed. Its geology is characterized by Triassic Hawkesbury Sandstone resting on Carboniferous strata, including Wollomi Assemblage volcanics and Berowra Supersuite granites. Because there are few limestone or dolomite formations, the water is soft and low in minerals. Sediments from the coastal plains add a few ions, but the water remains gently mineralized due to quartz-rich sandstones and acidic soils that limit the leaching of calcium and magnesium.

For homeowners, this soft water means less limescale buildup on appliances like kettles and heating elements, which can extend their lifespan and reduce the need for frequent descaling. You might notice that laundry detergents lather more easily, potentially allowing you to use less. While a water softener isn't necessary, occasional flushing of fixtures can help manage any minor staining from natural iron or manganese. The water's pH is 7.6, and fluoride is added to support dental health.