Gosnells Water Hardness & Quality Report (2026)
Water Hardness
Source
mixed
pH Level
8.1
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
564.6 mg/L
Est. Daily Cost
A$0.65
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 Gosnells, your appliances are currently losing 27% efficiency due to mineral buildup.
| Appliance | In Gosnells | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 2.8 yrs | 8.5 yrs | -67% |
| Washing Machine | 6 yrs | 12 yrs | -50% |
| Water Heater | 7.4 yrs | 15 yrs | -51% |
Regional Water Comparison
How Gosnells compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Gosnells, Western Australia | 205 mg/L | 🔴 Very Hard | mixed |
| Maddington, Western Australia | 166 mg/L | 🟠 Hard | mixed |
| Kelmscott, Western Australia | 237.5 mg/L | 🔴 Very Hard | mixed |
| Southern River, Western Australia | 120.5 mg/L | 🟠 Hard | mixed |
| Thornlie, Western Australia | 239.5 mg/L | 🔴 Very Hard | mixed |
National Benchmark
How Gosnells compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Gosnells | 205 mg/L | 🔴 High |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Gosnells's Water Unique?
Local geology and source profile
Gosnells' drinking water is supplied by the Water Corporation via the Integrated Water Supply Scheme (IWSS), blending Gnangara Mound limestone groundwater with desalinated supply from the Perth Seawater Desalination Plant for the City of Gosnells LGA inner south-eastern Perth metropolitan distribution in Western Australia. Water hardness in Gosnells is measured at 205 mg/L — classified as hard, marginally exceeding the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. The elevated TDS of 564.6 mg/L reflects the Gnangara Mound limestone groundwater character of the local IWSS supply, though slightly softer than adjacent Thornlie (239.5 mg/L) in the same LGA — confirming meaningful variation across the City of Gosnells distribution sub-zones.
Gosnells' hard supply reflects the Tamala Limestone groundwater character of the Gnangara Mound. The Gnangara groundwater system percolates through the Superficial Aquifer and Tamala Limestone — the porous Eocene carbonate formation underlying the Swan Coastal Plain — where calcium carbonate and dissolved salts accumulate. The inner south-east Gosnells LGA town centre distribution corridor receives an IWSS blend with a significant groundwater proportion, producing hard supply marginally above the ADWG 200 mg/L aesthetic threshold, lower than the adjacent Thornlie sub-zone (239.5 mg/L), suggesting a more favourable desalinated water blend proportion at the Gosnells distribution node.
Gosnells residents deal with significant daily limescale build-up on taps, shower screens, and in kettles — descaling every two to three weeks is common. Solar hot water systems popular in WA's sunny climate accumulate heavy scale; annual servicing is strongly recommended. Under WA water restrictions, garden irrigation is limited to two days per week. The elevated lead reading (0.004 mg/L) warrants briefly running the cold tap before use. The Water Corporation provides water quality information at watercorporation.com.au, with all ADWG health standards met throughout the Gosnells inner south-east supply zone.
Geology & Source: Supplied by the Water Corporation via the Integrated Water Supply Scheme from Gnangara Mound limestone groundwater blended with desalinated supply — the Gosnells LGA inner south-east Perth distribution carries hard water at 205 mg/L with elevated TDS of 564.6 mg/L, marginally exceeding the ADWG aesthetic guideline, reflecting the dominant Tamala Limestone Gnangara Mound groundwater in the local IWSS supply blend.