Mount Isa Water Hardness & Quality Report (2026)
Water Hardness
Source
mixed
pH Level
7.8
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
375.3 mg/L
Est. Daily Cost
A$0.42
energy & soap waste
Source: BOM National Performance Report & ADWG · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Mount Isa, your appliances are currently losing 18% efficiency due to mineral buildup.
| Appliance | In Mount Isa | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.2 yrs | 8.5 yrs | -39% |
| Washing Machine | 8.7 yrs | 12 yrs | -28% |
| Water Heater | 10.3 yrs | 15 yrs | -31% |
Regional Water Comparison
How Mount Isa compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Mount Isa, Queensland | 133.5 mg/L | 🟠 Hard | mixed |
| Alice Springs, Northern Territory | 320 mg/L | 🔴 Very Hard | groundwater |
| Edmonton, Queensland | 76.5 mg/L | 🟡 Moderately Hard | mixed |
| Cairns, Queensland | 50 mg/L | 🟢 Soft | river |
| Kelso, Queensland | 41 mg/L | 🟢 Soft | mixed |
National Benchmark
How Mount Isa compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Mount Isa | 133.5 mg/L | 🟠 Moderate |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Mount Isa's Water Unique?
Local geology and source profile
Mount Isa's drinking water is supplied by Mount Isa City Council Water, drawing from Lake Moondarra on the Leichhardt River approximately 24 kilometres north of the city, supplemented by local groundwater extraction to meet demand for this major outback mining city in Queensland. Water hardness in Mount Isa is measured at 133.5 mg/L — classified as moderately hard — within the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Mount Isa — one of Australia's most significant outback resource cities and home to the world-class Glencore copper, lead, and zinc mining complex — sources water from an inland reservoir catchment in the semi-arid north-west Queensland outback, with supply meeting Australian urban water quality standards across all ADWG parameters.
Mount Isa's moderately hard supply reflects the Proterozoic dolomite and limestone geology of the Mount Isa Block. The Leichhardt River watershed traverses ancient Proterozoic Mount Isa Group formations — including the Urquhart Shale, Kennedy Siltstone, and dolomite members — that are the host geology for the famous copper-lead-zinc ore bodies and that dissolve moderate calcium and magnesium into surface and groundwater. The mixed source classification at TDS 375.3 mg/L indicates supplementary groundwater extraction from Proterozoic aquifers that contribute additional mineral loading beyond the surface Leichhardt catchment alone.
Mount Isa residents face moderate daily limescale build-up on taps and in kettles — descaling every three to four weeks is typical. Hot water systems benefit from periodic inspection. Water efficiency is particularly important in outback Queensland's extreme climate where high temperatures and evaporation rates make water conservation critical. Mount Isa City Council provides water quality information online, with all ADWG health standards consistently met. Residents may use filters to improve the taste profile of the moderately mineralised supply in this unique outback city.
Geology & Source: Supplied by Mount Isa City Council Water from Lake Moondarra on the Leichhardt River, supplemented by local groundwater extraction — the Mount Isa supply carries moderately hard water at 133.5 mg/L with TDS of 375.3 mg/L, characteristic of the Proterozoic dolomite and limestone of the Mount Isa Block that moderately mineralises the outback north-west Queensland surface catchment and bore supply.