Tap Water Quality in Karragarra Island, QLD
Postcode 4184 · Supplied by Seqwater via Redland
Quality Score
About Karragarra Island
Karragarra Island is a suburb of 240 residents in Queensland (postcode 4184). The median age is 63. It falls within the Seqwater area. Neighbouring suburbs include Lamb Island, Macleay Island, Russell Island, Peel Island.
Most residents own outright (61%), while 22% own their home with a mortgage, while 13% rent. The median household income is $45,344 per year. The top countries of birth for residents are United Kingdom (35%), New Zealand (22%), and Germany (9%).
Tap water in Karragarra Island is supplied by Seqwater. The suburb receives water via the Redland supply zone.
Water quality summary
Based on recent water quality reports, Karragarra Island achieves a WaterScore of 9.5 out of 10, rated excellent overall. Water hardness measures 70.2 mg/L, classified as moderately hard. This may cause light mineral deposits on fixtures over time. The water is fluoridated at 0.85 mg/L, within the recommended range of 0.6–1.1 mg/L for dental health, well under the ADWG maximum of 1.5 mg/L. Chlorine, used for disinfection, measures 1.3 mg/L — well within the ADWG guideline of 5 mg/L. Some residents may notice a slight taste, which can be reduced by refrigerating water or using a carbon filter. Turbidity is 0.4 NTU, indicating clear water, within the ADWG guideline of 5 NTU. E. coli was not detected in testing, meeting the ADWG standard for microbiological safety.
Compare with nearby suburbs: Lamb Island , Macleay Island , Russell Island
Census Data
Suburb snapshot
Population
Median Age
Median Income
Owner-occupied
Recommended filters for Karragarra Island
Products matched to your water profile
BRITA
Marella 2.4L Fridge Water Filter Jug (Maxtra+)
4.7 · 16,095 ratings on Amazon
Ideal for Karragarra Island — removes chlorine taste and odour.
ZeroWater
2.8L 5-Stage Jug (IAPMO Certified: PFOA/PFOS + Lead)
4.2 · 5,315 ratings on Amazon
A reliable 2.8l 5-stage jug (iapmo certified: pfoa/pfos + lead) suitable for Karragarra Island's water profile.
Purewell
8.5L Stainless Steel Gravity System
4.4 · 1,137 ratings on Amazon
Ideal for Karragarra Island — removes chlorine taste and odour.
Comparison
How Karragarra Island compares
Compared to Queensland and national averages
| Metric | Karragarra Island | QLD Avg | National Avg |
|---|---|---|---|
| Hardness | 70.2 mg/L | 76.3 mg/L | 85.3 mg/L |
| pH | — | 6.2 | 7.8 |
| Fluoride | 0.85 mg/L | 0.8 mg/L | 0.7 mg/L |
| Chlorine | 1.3 mg/L | — | — |
| Turbidity | 0.4 NTU | 0.3 NTU | 0.4 NTU |
| TDS | — | — | 275.7 mg/L |
Full Results
Detailed water quality data
All values compared against Australian Drinking Water Guidelines (ADWG)
| Parameter | Value | Unit | ADWG Guideline | Status |
|---|---|---|---|---|
| Fluoride | 0.85 | mg/L | < 1.5 | Good |
| Free Chlorine | 1.3 | mg/L | < 5 | Good |
| Total Chlorine | 1.3 | mg/L | < 5 | Good |
| Arsenic | 0.0005 | mg/L | No limit | Measured |
| Cadmium | 0.0001 | mg/L | No limit | Measured |
| Chromium | 0.001 | mg/L | No limit | Measured |
| Copper | 0.001 | mg/L | < 2 | Good |
| Lead | 0.001 | mg/L | < 0.01 | Good |
| Manganese | 0.003 | mg/L | < 0.1 | Good |
| Mercury | 0.0001 | mg/L | No limit | Measured |
| Nickel | 0.001 | mg/L | No limit | Measured |
| E. coli | 0 | CFU/100mL | < 0 | Compliant |
| Trihalomethanes | 0.07390000000000001 | mg/L | < 0.25 | Good |
| Chloride | 51.6 | mg/L | < 250 | Good |
| Hardness | 70.2 | mg/L | < 200 | Good |
| Sodium | 24.7 | mg/L | < 180 | Good |
| Aluminium | 0.042 | mg/L | < 0.2 | Good |
| Iron | 0.02 | mg/L | < 0.3 | Good |
| Zinc | 0.005 | mg/L | No limit | Measured |
| Colour | 1 | HU | < 15 | Good |
| Turbidity | 0.4 | NTU | < 5 | Good |
| Calcium | 19.3 | mg/L | No limit | Measured |
| Magnesium | 5.22 | mg/L | No limit | Measured |
| Alkalinity | 34.8 | mg/L | No limit | Measured |
| Conductivity | 278.9 | µS/cm | No limit | Measured |
| Temperature | 25.5 | °C | No limit | Measured |
| Chlorate | 0.005 | mg/L | No limit | Measured |
| Ndma | 0.003 | µg/L | No limit | Measured |
Safety
Safety assessment
Based on 28 parameters tested, all results fall within Australian Drinking Water Guidelines. E. coli was not detected, meeting the ADWG standard for microbiological safety.
Based on comparison with Australian Drinking Water Guidelines (ADWG)
Explained
What these numbers mean
Moderately hard (70.2 mg/L)
Water Hardness
Your water is moderately hard. You may notice light limescale deposits on kettle elements and taps over time. Soap lathers reasonably well, though slightly more product may be needed. Skin and hair are generally unaffected, and appliance lifespan should not be significantly reduced at this level.
Data unavailable
pH Level
pH data is not currently available for Karragarra Island.
Fluoridated
Fluoride
Fluoride at 0.85 mg/L. Within the recommended 0.6–1.1 mg/L range for dental health.
Chlorine
Disinfection
Chlorine measured at 1.3 mg/L, well within the ADWG guideline of 5 mg/L. Used for disinfection to keep water safe. May affect taste slightly — refrigerating water or using a carbon filter can help.
Learn more about these measurements in our water quality glossary — including Hardness , pH , Fluoride , and ADWG guidelines .
Advice
Practical tips for residents
Reduce Chlorine Taste
Karragarra Island's chlorine level is 1.3 mg/L. An activated carbon jug filter or benchtop unit can noticeably reduce chlorine taste and odour from tap water.
Soft Water Advantage
Karragarra Island's water is moderately hard at 70.2 mg/L. You can use less soap and detergent, as it lathers easily with softer water.
Fluoride in Your Water
Fluoride measures 0.85 mg/L in Karragarra Island. Australian guidelines allow up to 1.5 mg/L. This is added by utilities to support dental health in the community.
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FAQ
Frequently asked questions
Is tap water safe to drink in Karragarra Island?
How hard is the water in Karragarra Island?
What water utility supplies Karragarra Island?
Does Karragarra Island water have fluoride?
What is the water quality score for Karragarra Island?
What is the population of Karragarra Island?
Supplier
Water utility
- Utility
- Seqwater
- Supply Zone
- Redland
- Data Source
- Seqwater — Redland
Nearby
Nearby suburbs
Same water utility, similar water quality
Similar Quality
Suburbs with similar water quality
Suburbs scoring between 8.5 and 10.0
Utility reports average the grid — not your home
Karragarra Island's water meets ADWG standards at the source, but old pipes, roof tanks, and ageing plumbing can add lead, copper or bacteria before the water reaches your tap. These won't show up in your utility report.
Check your own tap before buying a filter or assuming the suburb average matches your home.
Tetra
EasyStrips 6-in-1 Water Test (100 strips)
4.6 · 8,650 ratings on Amazon
Tests 6 parameters in 60 seconds: hardness, chlorine, pH, nitrate, nitrite, alkalinity. Cheapest way to verify your utility data.
Test my tap →Sponsored Amazon link. Check Amazon for current price and availability.
Heavy Metals
Drinking Water Test Kit (Lead, Copper, Iron, Mercury)
4.2 · 250 ratings on Amazon
20 tests. Detects lead, copper, iron, mercury — the things utility reports miss. Mobile-app results, EPA-standard thresholds.
Check metals kit →Sponsored Amazon link. Check Amazon for current price and availability.
Guides for Brisbane and South East Queensland
In-depth articles on the water supply that serves Karragarra Island
Cite
Cite this page
Free to quote and reuse with a credit to WaterScore and a link to this page. Journalists and researchers can find key figures and contacts on our press and data page.
WaterScore. (2026). Tap water quality in Karragarra Island, QLD [Data set]. Compiled from Seqwater data (annual report). https://waterscore.com.au/water-quality/karragarra-island-qld/
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Related
Explore more
Related pages for Karragarra Island, QLD
Is tap water safe?
Safety assessment
Water hardness
70.2 mg/L
Best water filter
Filter recommendations
Queensland water quality
State coverage
Seqwater
Water utility
Compare with Lamb Island
Karragarra Island vs Lamb Island
Compare with Macleay Island
Karragarra Island vs Macleay Island
Compare with Russell Island
Karragarra Island vs Russell Island
Disclaimer: The information on this page is for general informational purposes only and does not constitute medical advice, health recommendations, or professional guidance. Water quality data is sourced from Seqwater (annual report) and reflects conditions at the time of utility testing — it may not reflect real-time water quality at your tap. Actual water quality can vary due to local plumbing, seasonal changes, and distance from the treatment plant. For specific health concerns, consult a qualified health professional. For the most current water quality information, contact your local water utility directly. See our Terms of Use.