Sydney
Sydney, Australia has an estimated water hardness of 57 ppm (mg/L as calcium carbonate), which is classed as soft. Low scale risk. Use the lower end of detergent guidance.
Sydney water hardness in every unit
| Unit | Average |
|---|---|
| mg/L or ppm (CaCO₃) | 57 |
| mmol/L | 0.57 |
| German degrees (°dH) | 3.19 |
| French degrees (°fH) | 5.7 |
| Clark degrees (°e) | 4 |
| Grains per US gallon (gpg) | 3.33 |
Published range: 39–60 ppm.
Where Sydney's water comes from
- Supplier: Sydney Water (retail); WaterNSW manages the dams and raw-water supply
- Source: Five drinking-water catchments (Warragamba, Shoalhaven, Upper Nepean, Woronora and Blue Mountains) feeding 11 major dams
More than 80% of Sydney’s water comes from Warragamba Dam, and Prospect Water Filtration Plant supplies almost 85% of households. WaterNSW: the water supply system (checked 2026-10-05).
How Sydney compares
With an average of 57 ppm, Sydney ranks 12th hardest of the 19 cities in our directory, 9 ppm below the directory median of 66 ppm. Among the cities in our directory in Oceania, Adelaide is the hardest at 100 ppm and Melbourne is the softest at 25 ppm.
What the range means
Published figures for Sydney run from 39 to 60 ppm. The spread is relatively narrow (21 ppm), so the average is a reasonable guide, though your own tap can still differ from the citywide figure.
What soft water means at home
Soft water rarely leaves visible scale. Kettles, taps and shower screens stay clearer for longer, and detergents lather easily, so the main risk is overdosing. Start at the minimum amount on the pack and increase only if results are poor.
Appliance settings for 57 ppm water
- Dishwasher: salt no; lowest hardness band. Salt is usually unnecessary unless your manual says otherwise.
- Coffee machine: descale every 3–4 months; filter: usually optional.
- Laundry: use the soft-water dose. Start at the label minimum and adjust for soil level.
- Kettle: descale inspect every 3 months.
- Humidifier: tap water is usually suitable; clean weekly.
Frequently asked questions
How hard is the water in Sydney?
The estimate for Sydney, Australia is about 57 mg/L as calcium carbonate (3.19 °dH, 5.7 °fH, 3.33 gpg), with a published range of 39–60 mg/L. That is classed as soft water. Greater Sydney network estimate.
Do I need dishwasher salt in Sydney?
Usually not. Salt is usually unnecessary unless your manual says otherwise. Always follow your dishwasher manual.
How often should I descale a coffee machine in Sydney?
At this hardness, descale every 3–4 months. Water filter: usually optional.
Do I need a water softener in Sydney?
Almost certainly not. Soft water does not usually justify a softener.
Is hard water in Sydney safe to drink?
Water hardness is mainly an aesthetic and scale issue. The World Health Organization does not set a health-based guideline value for it. Hardness affects taste, scale and detergent use rather than drinking safety, and your utility is responsible for meeting drinking-water standards. If you have a specific health or dietary concern, ask your doctor.
Who supplies tap water in Sydney?
Sydney Water (retail); WaterNSW manages the dams and raw-water supply. Source: Five drinking-water catchments (Warragamba, Shoalhaven, Upper Nepean, Woronora and Blue Mountains) feeding 11 major dams.
How to check your own water
City averages are a starting point. To get your actual figure, look for the latest water-quality report from Sydney Water or your local supplier, or dip a hardness test strip in a glass of cold tap water and read it against the chart. Strips usually report in °dH, gpg or ppm; enter the number into the Waterdial checker to convert it and see the matching appliance settings. A manual reading always beats a city estimate.
Source
Sydney Water, checked 2026-10-05. Guidance is general; your appliance manual takes priority.
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