Cherrybrook Water Hardness & Quality Report (2026)
Water Hardness
~120–179 mg/L
Hardestimated · not lab-verified
Source
reservoir
pH Level
7.5
neutral = 7.0
Lead
0.003 mg/L
✓ Below action level
TDS
234.6 mg/L
Est. Daily Cost
A$0.47
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 Cherrybrook, your appliances are currently losing 20% efficiency due to mineral buildup.
| Appliance | In Cherrybrook | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6.8 yrs | 8.5 yrs | -20% |
| Washing Machine | 9.6 yrs | 12 yrs | -20% |
| Water Heater | 12 yrs | 15 yrs | -20% |
Regional Water Comparison
How Cherrybrook compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Cherrybrook, New South Wales | ≈ 120–179 mg/L | 🟠 Hard | reservoir |
| West Pennant Hills, New South Wales | ≈ 0–60 mg/L | 🟢 Soft | reservoir |
| Castle Hill, New South Wales | ≈ 0–60 mg/L | 🟢 Soft | reservoir |
| Hornsby, New South Wales | ≈ 0–60 mg/L | 🟢 Soft | reservoir |
| Carlingford, New South Wales | ≈ 0–60 mg/L | 🟢 Soft | reservoir |
National Benchmark
How Cherrybrook compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Cherrybrook | ≈ 120–179 mg/L | 🟠 Moderate |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Cherrybrook's Water Unique?
Local geology and source profile
The water serving Cherrybrook residents comes from Sydney Water, primarily utilizing the Prospect Water Filtration Plant. This plant processes water drawn from the Hawkesbury-Nepean River system, a major source for the Sydney region. The supply reaches homes in the Upper North Shore, including the Hornsby-adjacent distribution areas, ensuring a consistent flow of treated water to the community. This vast network highlights the scale of operations required to meet the daily water needs of a metropolitan area.
The geology underlying this region plays a significant role in the water's characteristics. The Hawkesbury-Nepean River flows through areas dominated by Sydney sandstone bedrock. This geological formation is known to impart moderate hardness to the water as it dissolves minerals. Additionally, the proportion of Hawkesbury-Nepean supply contributes to elevated Total Dissolved Solids (TDS), a measure of all substances dissolved in the water, reflecting the natural mineral content picked up from the bedrock.
Homeowners in Cherrybrook might notice the effects of moderately hard water on their appliances and plumbing. Over time, mineral buildup, or scale, can form inside pipes and water heaters, potentially reducing their efficiency and lifespan. You may also find that soap and detergents don't lather as easily. To combat this, regular descaling of appliances like kettles and coffee makers is a good practice. If you're concerned about the impact on your home, a water softener could be considered to reduce mineral content.
Geology & Source: Hawkesbury-Nepean supply; sandstone bedrock contributes to moderate hardness and elevated TDS
Other New South Wales Water Reports
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