Ngunnawal Water Hardness & Quality Report (2026)

Icon Water is the utility responsible for supplying drinking water to Ngunnawal and the wider Canberra region in the Australian Capital Territory. The water originates from the Cotter River catchment, a key part of the Upper Murrumbidgee River watershed. This raw water is stored in significant reservoirs like Bendora, Corin, and Cotter. From these sources, it flows to the Mount Stromlo Water Quality Control Centre for comprehensive treatment before reaching residents. Recent high rainfall has kept storage levels above 98% capacity, allowing for daily production volumes between 100 and 220 megalitres.

The underlying geology of the supply area is primarily composed of Paleozoic sedimentary rocks and granitic intrusions, characteristic of the Lachlan Fold Belt. Formations include shales and sandstones. These rock types naturally exhibit low weathering rates, meaning they don't easily dissolve minerals like calcium and magnesium into the water. Additionally, the forested catchment soils further limit the leaching of these hardness-contributing ions. This geological profile, combined with natural filtration through vegetation and soils, consistently results in soft water with minimal mineralisation.

Because the water is soft, homeowners in Ngunnawal will notice very little limescale buildup on appliances such as kettles and heating elements, which helps extend their lifespan. You'll also find that soaps and detergents lather very effectively, making washing feel more efficient and potentially reducing skin dryness. Unlike in areas with hard water, a water softener isn't necessary. Basic maintenance, like the occasional rinse of fixtures with vinegar, is usually sufficient for any minor deposits. Your laundry machines and dishwashers will operate without issue. While the WaterScore is a good 7.3/10, some samples have shown occasional E. coli detections, failing the zero-tolerance standard.