Saint Ives Water Hardness & Quality Report (2026)
Water Hardness
Source
reservoir
pH Level
7.9
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
332.5 mg/L
Est. Daily Cost
A$0.48
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 Saint Ives, your appliances are currently losing 20% efficiency due to mineral buildup.
| Appliance | In Saint Ives | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 4.6 yrs | 8.5 yrs | -46% |
| Washing Machine | 8 yrs | 12 yrs | -33% |
| Water Heater | 9.5 yrs | 15 yrs | -37% |
Regional Water Comparison
How Saint Ives compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Saint Ives, New South Wales | 152 mg/L | 🟠 Hard | reservoir |
| Pymble, New South Wales | 90 mg/L | 🟡 Moderately Hard | reservoir |
| Turramurra, New South Wales | 172 mg/L | 🟠 Hard | reservoir |
| Killara, New South Wales | 58 mg/L | 🟢 Soft | reservoir |
| Wahroonga, New South Wales | 123 mg/L | 🟠 Hard | reservoir |
National Benchmark
How Saint Ives compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Saint Ives | 152 mg/L | 🟠 Moderate |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Saint Ives's Water Unique?
Local geology and source profile
Saint Ives' drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant blending Warragamba Dam storage with a proportionally elevated Hawkesbury-Nepean component for the Ku-ring-gai LGA upper North Shore distribution in New South Wales. Water hardness in Saint Ives is measured at 152 mg/L — classified as moderately hard, approaching the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Saint Ives — a prestigious outer North Shore suburb of large bushland homes adjacent to Garigal National Park and Ku-ring-gai National Park — receives one of the harder supplies within the Sydney Water metropolitan network, consistent with the northward hardness gradient of the upper North Shore corridor that includes Wahroonga (123 mg/L) and the very hard Chatswood (179.5 mg/L) sub-zones.
Saint Ives' elevated hardness reflects the proportionally significant Hawkesbury-Nepean component in the upper North Shore Ku-ring-gai Prospect distribution blend. The Hawkesbury-Nepean system traverses Triassic Hawkesbury Sandstone and Cumberland Plain carbonate-cemented alluvial terrain — contributing calcium bicarbonate before Prospect treatment. The outer upper North Shore Saint Ives distribution sub-zone receives a notably higher Hawkesbury-Nepean fraction compared to the softer standard inner Sydney supply, raising hardness to 152 mg/L and TDS to 332.5 mg/L, consistent with the pattern of increasing hardness along the North Shore as the Hawkesbury-Nepean contribution rises.
Saint Ives residents face noticeable limescale build-up on taps, shower screens, and in kettles — descaling every three to four 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 in older established homes. Sydney Water provides water quality information at sydneywater.com.au, with all ADWG health standards consistently met. A water softener or quality filter is a practical household investment for this prestigious bushland suburb.
Geology & Source: Supplied by Sydney Water via the Prospect Water Filtration Plant blending Warragamba Dam with an elevated Hawkesbury-Nepean component — the Saint Ives Ku-ring-gai upper North Shore supply carries moderately hard water at 152 mg/L with TDS of 332.5 mg/L, reflecting the proportionally elevated Hawkesbury-Nepean contribution at this outer upper North Shore Ku-ring-gai distribution corridor.