Water Hardness in 78737
Austin, Texas · Hays County
Dataset updated March 9, 2026Matched to 14 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology
How this ZIP reading is built
This ZIP reading is built from 14 matched water systems. When more than one system is matched, the displayed value is weighted toward larger known service populations when that data is available.
Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.
Water Systems Serving 78737
These are the systems matched to this ZIP code. The displayed ZIP value is weighted toward larger known service populations when population data is available.
| Water System | Source | Hardness | Pop. Served |
|---|---|---|---|
City Of San Marcos TX1050001 | surface water | 150 PPM Moderately HardUSGS estimate: 208 PPM | |
City Of Kyle TX1050002 | surface water | 150 PPM Moderately HardUSGS estimate: 262 PPM | |
Texas State University - San Marcos TX1050003 | groundwater | 150 PPM Moderately HardUSGS estimate: 320 PPM | |
Goforth Sud TX1050019 | surface water | 150 PPM Moderately HardUSGS estimate: 262 PPM | |
County Line Sud TX1050038 | surface water | 150 PPM Moderately HardUSGS estimate: 262 PPM |
Nearby Zip Codes
What This Means For You
Recommendations are based on the displayed ZIP hardness reading. Confirm your tap reading before sizing or buying treatment equipment.
Moderately Hard Water
Your water is moderately hard. You're likely seeing scale buildup on fixtures, spotty dishes, and may notice dry skin or hair. A water softener or conditioner can help.
Recommended Products
Learn more: Do I Need a Water Softener? | Salt-Based vs Salt-Free | Size Calculator | How to Test Your Water
Know your water hardness?
If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Austin, TX (78737).
Frequently Asked Questions
Is the water hard in Austin, TX (78737)?
The average water hardness in 78737 is 150 PPM (8.8 GPG), which is classified as moderately hard.
Do I need a water softener in 78737?
With hardness of 150 PPM, a water softener is worth considering for homes in 78737.
Is hard water in 78737 safe to drink?
Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.
How many water systems serve 78737?
Zip code 78737 in Austin, Texas is served by 14 water systems.
Learn More About Your Water
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Salt-based softeners remove hardness minerals. Salt-free conditioners prevent scale but don't soften. Here's how to choose based on your water hardness level.
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We tested KDF, Vitamin C, and carbon shower filters for hard water. Here are the filters that actually reduce mineral buildup on hair and skin.
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