Dulwich Hill Water Hardness & Quality Report (2026)
Water Hardness
Source
reservoir
pH Level
8
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
393.2 mg/L
Est. Daily Cost
A$0.55
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 Dulwich Hill, your appliances are currently losing 23% efficiency due to mineral buildup.
| Appliance | In Dulwich Hill | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 3.9 yrs | 8.5 yrs | -54% |
| Washing Machine | 7.2 yrs | 12 yrs | -40% |
| Water Heater | 8.7 yrs | 15 yrs | -42% |
Regional Water Comparison
How Dulwich Hill compares to its nearest neighbours
| City | Hardness | Risk | Source |
|---|---|---|---|
| ▶ Dulwich Hill, New South Wales | 172.5 mg/L | 🟠 Hard | reservoir |
| Marrickville, New South Wales | 167 mg/L | 🟠 Hard | reservoir |
| Earlwood, New South Wales | 97.5 mg/L | 🟡 Moderately Hard | reservoir |
| Ashfield, New South Wales | 48.5 mg/L | 🟢 Soft | reservoir |
| Leichhardt, New South Wales | 110 mg/L | 🟡 Moderately Hard | reservoir |
National Benchmark
How Dulwich Hill compares to the Australia average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Dulwich Hill | 172.5 mg/L | 🟠 Moderate |
| Australia National Avg | 125 mg/L | 🟠 Moderate |
| Boronia Top Rated | 5 mg/L | 🟢 None |
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What Makes Dulwich Hill's Water Unique?
Local geology and source profile
Dulwich Hill's drinking water is supplied by Sydney Water, treated at the Prospect Water Filtration Plant with a high Hawkesbury-Nepean component for the Inner West LGA southern Sydney distribution in New South Wales. Water hardness in Dulwich Hill is measured at 172.5 mg/L — classified as hard, approaching the Australian Drinking Water Guidelines (ADWG) aesthetic guideline of 200 mg/L published by NHMRC. Dulwich Hill — an Inner West suburb undergoing urban renewal along the light rail corridor, known for the Dulwich Hill heritage conservation precinct, the Marrickville Road café and restaurant strip, the Dulwich Hill light rail terminus, and the Cooks River corridor parklands — carries a strikingly hard supply, significantly harder than the adjacent Newtown (121 mg/L), Leichhardt (110 mg/L), and Marrickville sub-zones in the same Inner West LGA.
Dulwich Hill's elevated hardness reflects a high Hawkesbury-Nepean component in the southern Inner West LGA Prospect distribution blend, delivered through a different supply main routing than the northern Inner West sub-zones. The Hawkesbury-Nepean system traverses Cumberland Plain alluvial terrain and Triassic carbonate-cemented sedimentary deposits — dissolving substantial calcium bicarbonate before Prospect treatment. The Dulwich Hill southern Inner West distribution at 172.5 mg/L and TDS 393.2 mg/L receives a proportionally very high Hawkesbury-Nepean fraction through the Cooks River sub-catchment distribution routing, distinct from the softer northern Inner West supply corridors.
Dulwich Hill residents face significant daily limescale challenges — kettle descaling every two to three weeks is typical, shower screens and tapware accumulate deposits. Hot water systems benefit from annual inspection. The elevated lead reading (0.004 mg/L) warrants briefly running the cold tap before use in Dulwich Hill's terrace homes and heritage residential properties. 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 Dulwich Hill's light rail connected inner-west community.
Geology & Source: Supplied by Sydney Water via the Prospect Water Filtration Plant with a high Hawkesbury-Nepean component — the Dulwich Hill Inner West LGA southern supply carries hard water at 172.5 mg/L with elevated TDS of 393.2 mg/L, significantly harder than adjacent Newtown (121 mg/L) and Leichhardt (110 mg/L) in the same Inner West LGA, reflecting the proportionally high Hawkesbury-Nepean fraction in the southern Inner West supply distribution corridor.