Best and Worst Water Quality Suburbs in Australia (2026)

Rye, a coastal suburb on Victoria’s Mornington Peninsula, scores 9.9 out of 10 on our WaterScore rating. At the other end of the scale, Tea Tree in Tasmania scores 6.2. That gap of 3.7 points reflects real differences in hardness, chlorine residuals, mineral content, and treatment outcomes across more than 8,000 scored suburbs. If you are searching for the best water quality suburbs in Australia, here is what the measured data shows for 2026.

We scored every suburb in our database using readings published by local water utilities. The results reveal clear geographic patterns: Victoria’s protected catchments produce consistently clean, soft water, while South Australia’s groundwater-fed regional towns carry heavy mineral loads. This guide ranks the top 10 and bottom 10 suburbs, breaks down results by state, and explains what drives the differences.

How We Scored 8,000+ Australian Suburbs

WaterScore rates each suburb from 0 to 10 based on measured water quality parameters reported by its supplying utility. The score factors in readings for hardness, pH, total dissolved solids (TDS), fluoride, chlorine, turbidity, and other parameters where data is available. Each reading is compared against the Australian Drinking Water Guidelines (ADWG) benchmarks.

Of the 17,585 suburbs in our database, 8,256 have enough utility data to generate a score. The national average sits at 8.8 out of 10, with a median of 8.9. Scores range from 6.2 to 10.0, which means even the lowest-scoring suburb in Australia delivers water well above minimum safety thresholds.

Suburbs with more measured parameters give us a fuller picture. Some suburbs have data for 20+ parameters; others have only 3 or 4. We note the parameter count in our tables so you can judge data depth for yourself.

Top 10 Best Water Quality Suburbs in Australia

Victoria dominates. Seven of the ten highest-scoring suburbs sit in greater Melbourne, supplied by water from protected mountain catchments in the Yarra Ranges and Central Highlands. The other three top spots go to remote South Australian and Northern Territory communities with very low mineral content.

Rank	Suburb	State	WaterScore	Hardness (mg/L)	Fluoride (mg/L)	Chlorine (mg/L)	Parameters
1	Rye	VIC	9.9	—	—	0.00	3
2	Belgrave	VIC	9.9	9	—	—	4
3	Nullarbor	SA	9.8	7	0.10	—	16
4	Yunyarinyi	SA	9.8	21	0.10	—	16
5	Devon Meadows	VIC	9.7	—	—	0.86	3
6	Adelaide River	NT	9.7	1	0.34	1.00	14
7	Monegeetta	VIC	9.7	52	0.06	0.32	14
8	Plenty	VIC	9.6	28	0.83	0.28	14
9	Glenroy	VIC	9.6	18	0.74	0.46	14
10	Chum Creek	VIC	9.6	8	—	0.50	10

The standout with the richest data is Nullarbor in South Australia. Despite being in a state known for hard water, Nullarbor records just 7 mg/L hardness across 16 measured parameters, with TDS of only 25 mg/L. Adelaide River in the Northern Territory is another strong performer, with hardness of just 1 mg/L, making it one of the softest water supplies in the country.

Among the Victorian suburbs, Belgrave and Chum Creek sit in Melbourne’s outer east, where Yarra Valley Water draws from the Upper Yarra and Silvan reservoirs. Glenroy in Melbourne’s north is supplied through the Greenvale system. Plenty and Monegeetta also benefit from Melbourne Water’s protected catchment supply. All of these suburbs receive naturally soft water, typically under 30 mg/L hardness.

Why Victoria Has the Best Water Quality Suburbs in Australia

Victoria’s state average WaterScore of 9.52 is the highest in Australia by a clear margin. The reason comes down to water source.

Melbourne’s supply draws from closed catchments in the Yarra Ranges and Central Highlands. These forested mountain reserves are off-limits to farming, development, and recreation. Rainfall filters through native forest and into reservoirs like the Thomson, Upper Yarra, and Maroondah. The result is naturally soft water with minimal mineral content and low turbidity.

The three retail water companies serving Melbourne — Yarra Valley Water, South East Water, and Greater Western Water — all benefit from this shared wholesale supply. Hardness across Melbourne typically ranges from 8 to 52 mg/L, well within the “soft” classification (under 60 mg/L on our water hardness calculator). Compare that with Adelaide, where SA Water delivers 87 to 138 mg/L in metro zones and over 600 mg/L in some regional areas.

Regional Victoria also performs well. Suburbs outside Melbourne score between 9.1 and 9.5, supported by local surface water reservoirs. For a detailed breakdown, visit the Victoria state overview.

Top 10 Lowest-Scoring Suburbs in Australia

Low scores do not mean unsafe water. Every suburb on this list still delivers water that meets ADWG health guidelines. The scores reflect how far each reading sits from ideal values across all measured parameters, including aesthetic factors like hardness and taste.

Rank	Suburb	State	WaterScore	Hardness (mg/L)	Fluoride (mg/L)	Chlorine (mg/L)	Parameters
1	Tea Tree	TAS	6.2	—	0.93	0.76	6
2	Williamsdale	ACT	7.3	39	0.80	0.64	21
3	Flynn	ACT	7.3	37.9	0.80	0.62	21
4	Taylor	ACT	7.3	37	0.80	0.76	21
5	Mount Stromlo	ACT	7.4	38	0.80	0.69	21
6	Padthaway	SA	7.4	602	0.10	0.90	16
7	Melrose	SA	7.4	366	1.10	1.00	17
8	Wild Dog Valley	SA	7.5	355	1.10	0.90	16
9	Wilkawatt	SA	7.5	575	1.00	1.30	17
10	Manly West	QLD	7.6	115	0.85	1.10	18

Two distinct patterns appear in the lowest-scoring suburbs.

The ACT suburbs (Williamsdale, Flynn, Taylor, Mount Stromlo) cluster between 7.3 and 7.4 with 21 measured parameters each. Icon Water publishes more data than most Australian utilities, which means more parameters contribute to the score calculation. Their individual readings are all within normal ranges, with soft water (37–39 mg/L hardness) and standard chlorine levels. The ACT’s low ranking reflects reporting depth more than water problems.

The South Australian suburbs tell a different story. Padthaway (602 mg/L) and Wilkawatt (575 mg/L) have extreme hardness driven by groundwater from limestone aquifers. These are among the hardest water suburbs in Australia, and that high mineral load pulls their overall score down. Melrose (366 mg/L) and Wild Dog Valley (355 mg/L) follow the same pattern, all well above the ADWG aesthetic guideline of 200 mg/L.

Tea Tree in Tasmania records the lowest score nationally at 6.2. TasWater supplies this area, though limited data (only 6 parameters) makes it harder to pinpoint the exact driver. As TasWater expands its published data, the picture for Tasmanian suburbs will become clearer.

What Drives Low Water Quality Scores

Three factors account for most low scores across Australia.

Extreme hardness. Suburbs drawing from limestone groundwater, particularly in regional South Australia, record hardness levels of 300 to 600+ mg/L. The ADWG sets 200 mg/L as an aesthetic guideline for hardness. Water above that level causes scale buildup on kettles and hot water systems, reduces soap performance, and affects taste. It is safe to drink, but it scores lower on overall quality. Read more about why Adelaide has Australia’s hardest water.

Detailed testing. Counterintuitively, suburbs with more measured parameters can score lower because there are more data points contributing to the calculation. The ACT’s 21-parameter dataset gives a thorough picture but also more opportunities for minor deductions. This does not mean the water is worse — it means the scoring is more granular.

Data gaps. Some suburbs have limited published data (3–6 parameters). This can push scores in either direction, making it harder to directly compare a 3-parameter suburb against a 21-parameter one. We are working with utilities to expand data coverage nationally.

Water Quality Rankings by State

State averages smooth out suburb-level variation and show broad regional patterns. Victoria leads, the ACT trails, and most states cluster between 8.5 and 9.1.

State	Avg WaterScore	Suburbs Scored	Lowest	Highest
VIC	9.52	571	9.1	10.0
WA	9.03	1,817	8.5	9.6
NSW	8.97	1,512	8.5	9.6
NT	8.97	378	8.6	9.7
SA	8.91	2,084	7.4	9.8
TAS	8.58	797	6.2	8.8
QLD	7.75	928	7.6	7.9
ACT	7.34	169	7.3	7.4

Victoria’s lead reflects its protected catchment advantage. Western Australia and New South Wales follow closely, both averaging just under 9.0. South Australia’s average of 8.91 is pulled up by good metro Adelaide zones (87–138 mg/L hardness) while its regional towns with very hard bore water (300–600+ mg/L) drag the extremes lower.

Queensland and the ACT sit notably below other states. Queensland’s 7.75 average reflects Seqwater’s reporting profile across South East Queensland supply zones. The ACT’s 7.34 reflects Icon Water’s detailed 21-parameter testing regime rather than genuinely poor water. Canberra’s readings are all within normal ranges; the low average is a scoring artefact of having more parameters measured.

The state data also reveals coverage variation. South Australia has the most suburbs scored (2,084) thanks to SA Water’s detailed zone-level reporting. Victoria has fewer scored suburbs (571) but the highest consistency from top to bottom.

How Australian Water Compares to ADWG Guidelines

The Australian Drinking Water Guidelines set health-based and aesthetic benchmarks for drinking water. Every suburb in our database meets the health-based guidelines. That is the most important finding from our analysis.

Where suburbs differ is on aesthetic parameters. The ADWG recommends:

• Hardness: below 200 mg/L (aesthetic)
• TDS: below 600 mg/L (aesthetic)
• pH: 6.5 to 8.5 (aesthetic)
• Chlorine: below 5 mg/L (health)
• Fluoride: below 1.5 mg/L (health)

Most top-scoring suburbs sit well within all of these limits. The hardest water suburbs exceed the 200 mg/L hardness guideline by up to three times, but this is an aesthetic concern, not a health risk. Your body needs calcium and magnesium; hard water simply delivers more of those minerals than most people prefer in their tea.

The ADWG also sets guideline values for emerging contaminants like PFAS. For suburb-level PFAS data, see our guide to PFAS in Australian water.

For a suburb-level comparison against these guidelines, use our water hardness calculator or check your suburb’s individual report.

What You Can Do

Whether your suburb ranks at the top or the bottom, there are practical steps to understand and improve your water.

1. Check your suburb’s report. Search for your suburb on WaterScore to see a full breakdown of measured parameters, your WaterScore rating, and how it compares to the ADWG guidelines and state averages.

2. Understand what the score means. A WaterScore of 7.5 does not mean unsafe water. It means some aesthetic parameters sit further from ideal values. Read the individual parameter readings on your suburb page to understand the specifics.

3. Consider a filter if hardness is high. If your suburb records hardness above 200 mg/L, a reverse osmosis system removes minerals effectively. For chlorine taste, a simple activated carbon filter works well. See our best water filter guide or check the filter recommendation for Adelaide if you are in a hard water area.

4. Test your water at home. A TDS meter (under $20) gives you a quick mineral content reading. Test strips for hardness, pH, and chlorine are available from hardware stores and provide a useful cross-check against utility data.

5. Contact your utility. If you have concerns about specific parameters, your local water utility publishes annual water quality reports. SA Water, Sydney Water, and other utilities provide detailed zone-level data on request.

Frequently Asked Questions

Which suburb has the best water quality in Australia?

Rye in Victoria and Belgrave in Victoria both score 9.9 out of 10 on the WaterScore rating. Victoria dominates the top 10, with seven of the ten highest-scoring suburbs located in Melbourne’s outer suburbs. The state’s protected mountain catchments and soft water supply contribute to consistently high scores.

Which suburb has the worst water quality in Australia?

Tea Tree in Tasmania records the lowest WaterScore at 6.2 out of 10 based on available data. The ACT suburbs of Williamsdale, Flynn, and Taylor follow at 7.3. Even the lowest-scoring suburbs still deliver water that meets ADWG safety standards.

Does Victoria have the best water quality suburbs in Australia?

Yes. Victoria has the highest average WaterScore of any state at 9.52 out of 10. Seven of the top 10 suburbs nationally are in Victoria. Melbourne’s water supply comes from protected mountain catchments in the Yarra Ranges and Central Highlands, producing naturally soft water with very low hardness, typically 8 to 52 mg/L.

Is low-scoring water unsafe to drink?

No. A lower WaterScore does not mean the water is unsafe. The score reflects overall quality across multiple parameters including hardness, chlorine levels, and mineral content. Even the lowest-scoring suburb (6.2 out of 10) delivers water that meets ADWG health guidelines. Most low scores are driven by aesthetic factors like very high hardness or elevated mineral content rather than safety concerns.

How can I check the water quality in my suburb?

Search for your suburb on WaterScore.com.au to see a detailed breakdown of measured water quality parameters, your suburb’s WaterScore rating, and how it compares to state and national averages. Each suburb page shows hardness, pH, chlorine, fluoride, and other key readings from your local water utility. You can also compare two suburbs side by side.

Summary

The best water quality suburbs in Australia cluster in Victoria, where protected mountain catchments produce soft, clean water scoring up to 9.9 out of 10. The lowest-scoring suburbs sit in Tasmania, the ACT, and regional South Australia, though even the bottom of the list (6.2) meets Australian safety guidelines. State averages range from Victoria’s 9.52 down to the ACT’s 7.34, with most states sitting between 8.5 and 9.1. Whether your suburb scores high or low, the data is there to help you understand exactly what is in your water and what you can do about it. Check your suburb’s report on WaterScore to see where you stand among the best water quality suburbs in Australia.

Sources

1. Australian Drinking Water Guidelines (ADWG), National Health and Medical Research Council, 2024
2. SA Water Annual Water Quality Data, SA Water, December 2024 to November 2025 reporting period
3. Melbourne Water Annual Report, Melbourne Water, 2024-25
4. Icon Water Drinking Water Quality Report, Icon Water, 2024-25
5. TasWater Annual Drinking Water Quality Report, TasWater, 2024-25
6. Seqwater Water Quality Reporting, Seqwater, 2024-25
7. Water Corporation Water Quality Annual Report, Water Corporation, 2024-25