Melbourne
Melbourne, Australia has an estimated water hardness of 25 ppm (mg/L as calcium carbonate), which is classed as soft. Low scale risk. Use the lower end of detergent guidance.
Melbourne water hardness in every unit
| Unit | Average |
|---|---|
| mg/L or ppm (CaCO₃) | 25 |
| mmol/L | 0.25 |
| German degrees (°dH) | 1.4 |
| French degrees (°fH) | 2.5 |
| Clark degrees (°e) | 1.75 |
| Grains per US gallon (gpg) | 1.46 |
Published range: 10–108 ppm.
Where Melbourne's water comes from
- Supplier: Melbourne Water (bulk supply) with retailers Yarra Valley Water, City West Water and South East Water
- Source: Protected forested catchments in the Yarra Ranges and Central Highlands, stored in reservoirs such as Thomson, Upper Yarra and Silvan
Around 80% of Melbourne’s water comes from uninhabited forest catchments. Which retailer serves you depends on your suburb. Melbourne Water (overview) (checked 2026-10-05).
How Melbourne compares
With an average of 25 ppm, Melbourne ranks 16th hardest of the 19 cities in our directory, 41 ppm below the directory median of 66 ppm. Among the cities in our directory in Oceania, Adelaide is the hardest at 100 ppm.
What the range means
Published figures for Melbourne run from 10 to 108 ppm. That is a wide spread (98 ppm), so the figure at your own tap could differ a lot from the average. Supply zones, blending of different water sources, and the time of year can all move it. A test strip or your utility's postcode lookup is worth the extra step here.
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 25 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 Melbourne?
The estimate for Melbourne, Australia is about 25 mg/L as calcium carbonate (1.4 °dH, 2.5 °fH, 1.46 gpg), with a published range of 10–108 mg/L. That is classed as soft water. Metro estimate; outer-west zones may be harder.
Do I need dishwasher salt in Melbourne?
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 Melbourne?
At this hardness, descale every 3–4 months. Water filter: usually optional.
Do I need a water softener in Melbourne?
Almost certainly not. Soft water does not usually justify a softener.
Is hard water in Melbourne 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 Melbourne?
Melbourne Water (bulk supply) with retailers Yarra Valley Water, City West Water and South East Water. Source: Protected forested catchments in the Yarra Ranges and Central Highlands, stored in reservoirs such as Thomson, Upper Yarra and Silvan.
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 Australian utility reports summary 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
Australian utility reports summary, checked 2026-10-05. Guidance is general; your appliance manual takes priority.
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