Dallas-Fort Worth Water Hardness Map
Typical water hardness levels by North Texas city, in grains per gallon. Use it as a starting point \u2014 your home's exact number takes a quick water test.
Hardness is measured in grains per gallon (gpg). Anything above 7 gpg is considered hard; above 10.5 gpg is very hard. Most of Dallas-Fort Worth falls in one of those two categories.
Hardness by city
| City | Hardness (gpg) | Notes |
|---|---|---|
| Dallas | 8–11 | Hard to very hard, with chloramine disinfection |
| Plano | 7–10 | NTMWD-supplied, hard to very hard |
| Frisco | 8–11 | Very hard, common scale on glassware |
| McKinney | 8–11 | Lavon/Texoma blend, hard with chloramine |
| Allen | 8–10 | Hard surface water with chlorine |
| Prosper | 9–12 | Very hard, scaling common in new builds |
| Southlake | 8–11 | Hard to very hard, chlorinated |
| Colleyville | 8–11 | Moderately to very hard |
| Westlake | 8–11 | Hard, often paired with whole-home filtration |
| Grapevine | 8–11 | Lake Grapevine source, hard with chloramine |
| Flower Mound | 9–12 | Frequently tests very hard |
| Richardson | 8–11 | NTMWD, hard with chloramine |
| University Park | 8–11 | Hard, paired with RO in many homes |
| Highland Park | 8–11 | Hard, common in luxury filtration installs |
Frequently asked questions
What hardness counts as hard water?
The U.S. Geological Survey considers 7–10.5 grains per gallon hard and anything above 10.5 very hard.
Is my city's hardness number the same as my home's?
Close, but the only way to know your home's exact number is to test the water at your tap. Plumbing age and any pre-existing treatment can shift the reading.
Does hardness change by season?
Slightly. Surface-water sources can vary modestly through the year as reservoirs refill and treatment blends shift.
Get your home's exact hardness number
Schedule your complimentary in-home water test. We'll walk you through the results and give honest recommendations — no high-pressure sales.
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