Does Dallas Have Hard Water? Dallas Water Hardness Explained
Short answer: yes, moderately hard to hard. In a December 2023 memo to the City Council, the City of Dallas stated that its water hardness ranges from 120 to 155 mg/L as CaCO3, about 7 to 9 grains per gallon. Dallas draws all of its water from six surface reservoirs and disinfects with chloramine, not chlorine.
How Hard Is Dallas Water?
| Measurement | Dallas | USGS Class |
|---|---|---|
| Hardness (mg/L as CaCO3) | 120 to 155 | Upper moderately hard to hard |
| Grains per gallon | About 7.0 to 9.1 | Hard water starts at about 7.1 gpg |
That puts Dallas in the middle of the pack: harder than naturally soft-water cities, but well below very hard cities like Phoenix (172 to 302 ppm). It is similar to Chicago's Lake Michigan water. Hardness at your tap can still vary, so test it before sizing a softener.
Where Dallas Water Comes From
According to the City of Dallas, the city draws water from six surface water reservoirs and uses no groundwater. Its three treatment plants draw from different lakes:
| Treatment Plant | Source Reservoirs |
|---|---|
| East Side Water Treatment Plant (Sunnyvale) | Lake Ray Hubbard, Lake Tawakoni, Lake Fork |
| Elm Fork Water Treatment Plant | Lake Ray Roberts, Lake Lewisville, Lake Grapevine, via the Elm Fork of the Trinity River |
| Bachman Water Treatment Plant | Lake Ray Roberts, Lake Lewisville, Lake Grapevine, via the Elm Fork of the Trinity River |
Reservoir water picks up calcium and magnesium from the limestone and soils of North Texas watersheds. Because different plants draw from different lakes, the hardness reaching your home may differ slightly from a neighbor's across town.
Dallas Uses Chloramine
The City of Dallas says it uses chloramine instead of chlorine, formed by combining chlorine and ammonia, to avoid the byproducts chlorine alone can produce. This matters if you are shopping for a shower filter: NSF/ANSI 177 shower filter certification covers free chlorine, not chloramine, and independent testing has shown even certified filters may not reduce chloramine. In Dallas, a shower filter will do less than in a chlorine city. For hair and skin issues linked to hardness, a chelating shampoo or water softener is a better investment. See do shower filters work?
Aquarium and dialysis note: chloramine must be removed before water is used in fish tanks or home dialysis. Use a dechlorinator labeled for chloramine, and follow your medical provider's guidance for dialysis.
Dallas Suburbs and Other Utilities
This guide covers water from Dallas Water Utilities. Many North Texas cities buy water from Dallas, while others are served by separate systems such as the North Texas Municipal Water District, which uses different sources and treatment. Hardness and disinfectant can differ, and some suppliers temporarily switch disinfectant during annual maintenance. Check the name on your water bill and read that utility's annual water quality report.
What Dallas Water Does to Hair, Skin and Appliances
Hair
At 120 to 155 mg/L, mineral buildup on hair builds gradually. Color-treated, bleached and curly hair show it first: dullness, roughness and conditioner that seems less effective. A chelating shampoo every week or two usually keeps it under control. See what the research shows.
Skin
Hard water leaves more soap residue on skin, and research links it to dry skin and higher eczema risk in young children. North Texas summers and indoor air conditioning can add to dryness. See hard water and skin.
Appliances
Expect moderate scale on faucets, showerheads, kettles and in water heaters. Regular descaling handles most of it. See how to remove limescale, water heaters and washing machines.
Best Solutions for Dallas Homes
| Problem | Best Fix in Dallas |
|---|---|
| Mineral buildup on hair | A chelating shampoo, such as OUAI Detox weekly or Ion Hard Water daily |
| Scale on fixtures and appliances | Regular descaling, or a water softener for homeowners |
| Chloramine taste in drinking water | A carbon block filter rated for chloramine, or reverse osmosis |
| Shower water | Manage expectations: shower filters are certified for chlorine, not chloramine |
Softener sizing example: a family of four at about 9 grains per gallon needs roughly 2,700 grains of softening a day (4 x 75 gallons x 9 gpg), or about 19,000 grains a week. That is a standard residential softener. See our sizing guide.
How to Check Your Own Dallas Tap Water
The city's range covers the whole system. To know your home's number:
- Check your bill to confirm Dallas Water Utilities is your supplier.
- Read the annual water quality report for your utility. Dallas Water Utilities publishes one every year; some years' reports focus on regulated contaminants and do not list hardness, so you may need to ask by calling 3-1-1.
- Test at home with hardness test strips for a quick range, or a drop-count titration kit for an exact grains-per-gallon number.
- Test more than once, a few weeks apart, since plant and lake blends can shift.
If your result is well above 155 mg/L, double-check your supplier and your home: a private well, a building with its own treatment, or an old water heater shedding scale can all change what you measure. Full instructions are in our water testing guide.
Frequently Asked Questions
Yes. The City of Dallas reports water hardness of 120 to 155 mg/L as calcium carbonate, which is moderately hard to hard on the USGS scale.
About 7 to 9 grains per gallon, based on the city's reported range of 120 to 155 mg/L.
From six surface reservoirs: Lake Ray Hubbard, Lake Tawakoni and Lake Fork for the East Side plant, and Lake Ray Roberts, Lake Lewisville and Lake Grapevine for the Elm Fork and Bachman plants. Dallas uses no groundwater.
Chloramine. The City of Dallas says it uses chloramine instead of chlorine to avoid disinfection byproducts that chlorine alone can form.
Less well than in chlorine cities. Shower filter certification covers free chlorine, not chloramine, which Dallas uses. A chelating shampoo or water softener helps more with hard water effects.
It is optional. At 120 to 155 mg/L, scale is moderate. A softener reduces scale and helps soap work better, but many homes manage with descaling and a chelating shampoo.
Hardness varies by utility and source. Check each city's water quality report; we only report figures we can trace to the utility.
Those are calcium and magnesium left behind when water evaporates. At 120 to 155 mg/L, spots on glass and fixtures are common. Wipe surfaces dry, use a rinse aid in the dishwasher, and descale with vinegar or citric acid.
Last updated: October 2026. Sources: City of Dallas memorandum (Dec. 2023); Dallas Water Utilities water quality information.