Water hardness in Austin
5.4 gpg moderately hard
Tap water in Austin is moderately hard: 5.4 gpg (93 mg/L · 5.2 °dH · 9.3 °fH).
Source: Austin Water 2025 Water Quality Report, Total Hardness as CaCO3 (utility web page) (2025) · data checked 2026-10-19
Range across supply zones: 70–126 mg/L.
Austin Water lists total hardness as CaCO3 from 2025 sampling at the treatment plants: an average of 93 mg/L (5.4 gpg), with a low of 70 and a high of 126 mg/L. That is moderately hard, and the figure is citywide rather than split by zone. Kettle scale builds up slowly, and a scale inhibitor can be enough for the water heater.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 5.4 gpg |
|---|---|
| Utility | Austin Water |
How Austin compares
- Tap water in Austin is 40 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1053 of 1372 in the United States (1 = hardest); 23 % of these cities have softer water.
- In Texas it is number 52 of 60 cities; the regional median is 8.6 gpg.
- Nearest city with clearly softer water: Bryan, 139 km away (0.5 gpg).
- Nearest city with clearly harder water: Round Rock, 28 km away (14.5 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Austin
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Austin water hard or soft?
It is moderately hard: 93 mg/L as CaCO₃ (5.4 gpg, 5.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Austin safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Austin water?
5.4 gpg, equal to 5.2 °dH, 9.3 °fH or 93 mg/L calcium carbonate.
What dishwasher salt setting should I use in Austin?
For 93 mg/L (5.2 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Austin?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Austin Water 2025 Water Quality Report, Total Hardness as CaCO3 (utility web page) (2025). Method: own measurement. Austin Water 2025 Water Quality Report, Total Hardness as CaCO3 (utility web page) · Outdated figure? Tell us