Doonside Water Hardness & Quality Report (2026)
Water Hardness
Source
reservoir
pH Level
7.8
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
298.7 mg/L
Est. Daily Cost
A$0.44
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 Doonside, your appliances are currently losing 19% efficiency due to mineral buildup.
| Appliance | In Doonside | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5 yrs | 8.5 yrs | -41% |
| Washing Machine | 8.4 yrs | 12 yrs | -30% |
| Water Heater | 10 yrs | 15 yrs | -33% |
Regional Water Comparison
How Doonside compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Doonside, New South Wales | 140 mg/L | 🟠 Hard | reservoir |
| Rooty Hill, New South Wales | 186 mg/L | 🔴 Very Hard | reservoir |
| Quakers Hill, New South Wales | 88 mg/L | 🟡 Moderately Hard | reservoir |
| Blacktown, New South Wales | 78 mg/L | 🟡 Moderately Hard | reservoir |
| Mount Druitt, New South Wales | 30.5 mg/L | 🟢 Soft | reservoir |
National Benchmark
How Doonside compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Doonside | 140 mg/L | 🟠 Moderate |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Doonside's Water Unique?
Local geology and source profile
Doonside's drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant incorporating a significant Hawkesbury-Nepean component for the Blacktown City LGA outer western Sydney distribution in New South Wales. Water hardness in Doonside is measured at 140 mg/L — classified as moderately hard — within the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Doonside — a large outer western Sydney suburb in the Blacktown LGA, known for the Woodcroft residential estates, the Doonside railway station precinct, and the multicultural residential character of the outer western Sydney growth corridor adjacent to Blacktown City — receives supply harder than the adjacent Seven Hills (94.5 mg/L) in the same Blacktown LGA, reflecting the higher Hawkesbury-Nepean proportion at the inner Blacktown distribution sub-zone.
Doonside's elevated hardness reflects a significant Hawkesbury-Nepean component in the Blacktown LGA inner Prospect distribution blend. The Hawkesbury-Nepean system traverses Cumberland Plain alluvial terrain and Triassic carbonate-cemented Hawkesbury Sandstone sedimentary deposits — dissolving substantial calcium bicarbonate before Prospect treatment. The Doonside inner Blacktown outer western distribution at 140 mg/L and TDS 298.7 mg/L receives a proportionally higher Hawkesbury-Nepean fraction through its inner distribution routing than the softer outer western Seven Hills sub-zone (94.5 mg/L) in the same Blacktown LGA.
Doonside residents face moderate limescale build-up on taps and in kettles — descaling every two to three weeks is typical. Hot water systems benefit from annual inspection. The elevated lead reading (0.004 mg/L) warrants briefly running the cold tap before use. Sydney Water provides water quality information at sydneywater.com.au, with all ADWG health standards consistently met. A point-of-use water filter is a practical investment for Doonside's outer western Sydney residential community.
Geology & Source: Supplied by Sydney Water via the Prospect Water Filtration Plant with a significant Hawkesbury-Nepean component — the Doonside Blacktown LGA outer western Sydney supply carries moderately hard water at 140 mg/L with elevated TDS of 298.7 mg/L, harder than the adjacent Seven Hills (94.5 mg/L) in the same Blacktown LGA, reflecting the higher Hawkesbury-Nepean proportion in the Blacktown–Doonside inner distribution sub-zone.