Australian tap water is hard in some places and soft in others. Perth’s northern suburbs hold the hardest readings any capital city utility publishes. Melbourne, Sydney and Canberra are soft. This guide gives Australia water hardness figures city by city. Every number names its source and its year.
Hardness counts the calcium and magnesium dissolved in your water. Rock and soil put them there. Our geology guide answers one question: where does hard water come from?
How is water hardness measured in Australia?
Australia measures hardness in mg/L (as calcium carbonate). Water suppliers often write it as ppm. Both mean the same thing. The number counts the dissolved calcium and magnesium in your water. A higher number means more scale on your kettle, taps and shower screen.
Your water retailer publishes a figure for your supply zone. It doesn’t publish one for your street. The figure also moves with the season and with the source your retailer is using that month.
So treat a city average as a rough guide. Treat your own zone figure as the real number.
What do the Australian Drinking Water Guidelines say about hardness?
The Australian Drinking Water Guidelines set four hardness bands. Under 60 mg/L is soft, and it can be corrosive. Between 60 and 200 mg/L is good quality. From 200 to 500 mg/L, scaling problems grow. Above 500 mg/L, the scaling is severe.
| Hardness (mg/L as calcium carbonate) | What the guidelines call it |
|---|---|
| Under 60 | Soft, but possibly corrosive |
| 60 to 200 | Good quality |
| 200 to 500 | Increasing scaling problems |
| Over 500 | Severe scaling |
Source: the Australian Drinking Water Guidelines hardness fact sheet, published by the NHMRC (2011, updated since).
The NHMRC guidelines say hardness should stay under 200 mg/L. That limit keeps scale out of hot water systems. It’s an aesthetic guideline. It’s not a health limit. Hard water is safe to drink.
You’ll see a finer scale on many water websites. It calls 60-120 mg/L moderately hard and 120-180 mg/L hard. That’s a common industry scale. The Australian guidelines don’t use those words at all. This site uses the four bands above, and labels anything else as the industry scale.
Which Australian city has the hardest water?
Perth’s northern localities have the hardest tap water in any capital. Two Rocks averaged 228 mg/L in 2024-25. Adelaide’s metro average is about 97 mg/L. Melbourne, Sydney and Canberra all sit in the soft band. Brisbane sits mid-band, near 118 mg/L on Seqwater’s latest testing.
| City | Hardness (mg/L as calcium carbonate) | Guideline band | Source and year |
|---|---|---|---|
| Perth | 27 to 228 across localities | Soft up to increasing scaling | Water Corporation, Perth aesthetic tables, 2024-25 |
| Adelaide | about 97, metro average | Good quality | WaterScore, from SA Water data, Nov 2025 |
| Melbourne | 9 to 38 in the main storages | Soft | Melbourne Water salinity table, Oct 2024 |
| Sydney | about 57 | Soft | Sydney Water, checked Sep 2026 |
| Canberra | about 43 | Soft | Icon Water, checked Sep 2026 |
| Brisbane | about 118 | Good quality | Seqwater Brisbane zone, 12 months to Aug 2026 |
One point gets missed in most city rankings. Adelaide’s quoted metro average sits a shade above the 96 mg/L figure people quote for Perth. Perth still holds the hardest localities by a wide margin. Averages and localities answer two different questions.
Your own number decides what you need. We make hard water filters for home, built for the bathroom. Check your city below, then check your suburb.
Perth water hardness
Perth has the widest spread of any capital city. Water Corporation’s 2024-25 Perth aesthetic tables give the figures by locality.
| Locality | Average (mg/L) | Maximum (mg/L) |
|---|---|---|
| Two Rocks | 228 | 240 |
| Yanchep | 198 | 210 |
| Wanneroo | 125 | 150 |
| Mundaring | 98 | 99 |
| Mandurah | 50 | 52 |
| Dwellingup | 29 | 31 |
The lowest single reading in the Perth region was 27 mg/L, at Dwellingup.
A city average of 96 mg/L gets quoted everywhere. That number is WaterScore’s calculation from Water Corporation’s 2023-24 data. Water Corporation itself publishes no city average, so don’t credit 96 to them.
Two Rocks and Yanchep sit over the northern groundwater system. Water moving through limestone picks up calcium, and those two localities show it. Our guide to Perth water hardness goes suburb by suburb.
Adelaide water hardness
Adelaide’s metro average is about 97 mg/L. That figure comes from WaterScore, using SA Water data from November 2025. SA Water publishes no metro average of its own.
SA Water gives you your own number instead. Its Your drinking water profile tool takes a postcode or suburb. SA Water puts it plainly. It treats more than 200 milligrams per litre as hard water.
Some Adelaide suburbs run above the metro average. Some run below it. We only quote a suburb figure after an SA Water lookup, and we record the date of the lookup.
Our guide to Adelaide water hardness covers the metro suburbs.
Does Melbourne have hard water?
No. Melbourne’s tap water is soft. Melbourne Water’s main storages ran between 9 and 38 mg/L in its October 2024 table. Silvan, Sugarloaf and Greenvale supply most of the city. A few towns on the north-west edge are harder. Gisborne and Macedon sit near 107 mg/L.
Melbourne Water’s salinity table lists hardness for each storage. Upper Yarra ran 9 to 14 mg/L. Sugarloaf ran 16 to 28 mg/L. Tarago was the highest at 27 to 38 mg/L.
Werribee is soft too, at about 23 mg/L. That figure is WaterScore’s, from Greater Western Water’s 2023-24 report. Werribee and Hoppers Crossing take bulk supply from the same storages as the rest of Melbourne. Older pages that call them hard are wrong, and this one used to be one of them.
Gisborne, Riddells Creek and Macedon run near 107 mg/L. Darley is about 95 mg/L. Those four figures are WaterScore’s, from Greater Western Water’s 2023-24 report. Those towns use local sources, not the big Melbourne storages. Greater Western Water’s drinking water quality report publishes results by locality for the west and north-west.
Our Melbourne guide answers one question: does Melbourne have hard water? We go suburb by suburb.
Sydney water hardness
Sydney Water’s water analysis page puts greater Sydney at about 57 mg/L. It uses the same cut-off the guidelines use. Under 60 mg/L counts as soft.
Sydney draws from protected mountain catchments. Those catchments carry few minerals. Limescale is a small problem in Sydney homes.
Soft water behaves differently in the shower. Soap lathers fast and feels slippery on the skin. Our guide to the difference between soft and hard water covers what changes.
Our Sydney guide, does sydney have hard water, covers the catchments and the chlorine question.
Brisbane water hardness
Seqwater supplies the bulk water for south east Queensland. Its Brisbane zone averaged 118 mg/L over the twelve months to August 2026. Individual results ran from 60 to 160 mg/L. All 175 samples passed the 200 mg/L guideline.
That puts Brisbane in the good quality band. It is neither a soft water city nor a hard one. Wet weather pushes the number up. Mt Crosby is Brisbane’s main treatment plant. It recorded a single result of 250 mg/L in November 2024, after heavy rain in the Mid-Brisbane River catchment.
Brisbane has held fairly steady over fifteen years. Urban Utilities’ 2010-11 Brisbane report gave a mean of 136 mg/L, ranging from 67 to 220. Today’s figure is a little lower.
Nobody publishes Brisbane hardness by suburb. Seqwater reports by supply zone, and it says those zone boundaries can change week to week. So read the Hardness row in Seqwater’s report tool, or test your own tap.
Two corrections to the old version. This page used to say Brisbane averaged 40-70 mg/L and called it soft. That was wrong, and we’ve taken it out. Lake Macdonald supplies Noosa and the Sunshine Coast. It doesn’t supply Brisbane.
Canberra water hardness
Icon Water calls Canberra’s water soft. Its appliance page gives about 43 mg/L (as calcium carbonate). See Icon Water on water quality and your appliances, checked September 2026.
At 43 mg/L, Canberra sits well inside the soft band. Scale on a kettle or showerhead builds up slowly there.
Icon Water publishes the number because dishwashers ask for it. If your machine wants a hardness setting, 43 mg/L is the figure to work from.
What about regional and bore water?
Regional supplies vary far more than city ones. Some country schemes run above the 200 mg/L guideline. Urban Utilities reported Beaudesert and Kooralbyn at 210 mg/L in 2022-23. No utility report covers a private bore. If you’re on bore water, test it yourself.
Urban Utilities reported both schemes at 210 mg/L in 2022-23. Both sat above the aesthetic guidance value of 200 mg/L in that year’s report.
We won’t put a number on private bore water. Bore hardness depends on the aquifer under your property. Two farms in one district can test very differently.
How do you check water hardness by postcode?
Your city average hides your suburb. Go to your own water supplier for the real figure. SA Water has a postcode lookup. Water Corporation and Urban Utilities publish yearly tables by locality. Melbourne readers go to their retailer, not to Melbourne Water. A home test gives you a number today.
Where to look:
- Perth and WA: Water Corporation drinking water quality reports. Pick your region, then open the aesthetic data tables.
- Adelaide and SA: SA Water’s postcode lookup. Type in your postcode or suburb.
- Melbourne: your retailer, not Melbourne Water. Greater Western Water, Yarra Valley Water and South East Water each publish a yearly report by locality.
- Sydney: Sydney Water’s water analysis page.
- Canberra: Icon Water’s water quality pages.
- Brisbane and south east Queensland: Seqwater’s water quality report tool. Pick the Brisbane zone and read the Hardness row. It updates monthly.
Your suburb figure may differ from your city figure. It can move between summer and winter too. If you want a number today, test for hard water at home with strips or the soap test.
Hard water shows up first on your showerhead and your shower screen. A shower filter reduces chlorine, heavy metals and sediment at that one tap. It also reduces calcium and magnesium. See our hard water filters if your suburb number came back high.
Frequently asked questions
Does Australia have hard water?
Yes, in parts of it. Hardness changes sharply by city and by suburb. Perth’s Two Rocks averaged 228 mg/L in 2024-25. Melbourne’s main storages ran 9 to 38 mg/L in 2024. Most Australian city water sits in the guideline band for good quality, between 60 and 200 mg/L.
Which Australian city has the hardest water?
Perth holds the hardest localities of any capital. Two Rocks averaged 228 mg/L and Yanchep 198 mg/L in the 2024-25 Water Corporation tables. Adelaide’s metro average of about 97 mg/L is close to Perth’s commonly quoted 96. Perth wins on its worst suburbs, not on its average.
Is Brisbane water hard or soft?
Brisbane is neither. Seqwater averaged 118 mg/L across its Brisbane supply zone in the twelve months to August 2026. Results ranged from 60 to 160 mg/L. That sits in the middle of the good quality band, so Brisbane is not soft and not hard.
Is 200 mg/L a health limit for hard water?
No. The Australian Drinking Water Guidelines set 200 mg/L as an aesthetic guideline. It’s there to keep scale out of hot water systems. Water above 200 mg/L is still safe to drink. The problems are practical ones: scale, poor lather and marks on glass and taps.
How do I find my suburb’s water hardness?
Ask your own water supplier. SA Water takes a postcode and gives your profile. Water Corporation publishes yearly tables by locality for WA. Urban Utilities does the same for south east Queensland. Melbourne readers go to their retailer. A home test strip gives you a number in minutes.
Last reviewed September 2026 by Lena Hartman
Data note: every figure on this page names its source and its year. Water utilities publish new reports each year. Open the linked source for the newest number before you act on it.