How does Southlake's water compare to the national average?

The USA national average is 151 mg/L. Southlake (≈ 120–179 mg/L) is 1 mg/L softer than average.

Southlake Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

8.5

neutral = 7.0

Lead

0.006 mg/L

✓ Below action level

TDS

854.2 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Southlake, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Southlake	Soft Water City	Efficiency Loss
Kettle	6.8 yrs	8.5 yrs	-20%
Washing Machine	9.6 yrs	12 yrs	-20%
Water Heater	12 yrs	15 yrs	-20%

Regional Water Comparison

How Southlake compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Southlake, Texas	≈ 120–179 mg/L	97.8 ppt	🟠 Hard	reservoir
Grapevine, Texas	117 mg/L	289.2 ppt	🟡 Moderately Hard	reservoir
Colleyville, Texas	≈ 120–179 mg/L	78.9 ppt	🟠 Hard	reservoir
Trophy Club, Texas	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Flower Mound, Texas	≈ 180+ mg/L	290.9 ppt	🔴 Very Hard	reservoir

National Benchmark

How Southlake compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Southlake	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Southlake's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 854.2 mg/LpH: 8.5

The City of Southlake Utilities Department serves approximately 32,000 residents across 27 square miles in Tarrant and Denton Counties, Texas. Water is sourced exclusively from surface supplies — Lake Lewisville and Lake Ray Roberts on the Elm Fork Trinity River — with treatment occurring at the city's O.H. Ivie Water Treatment Plant, which blends and processes raw reservoir water to meet drinking standards before distribution.

The supply originates in the Trinity River Basin watershed, spanning Cretaceous sedimentary rocks including the Glen Rose, Paluxy, and Antlers formations. These limestone and dolomite layers, part of the broader Trinity Aquifer system in North Texas, influence surface runoff chemistry through mineral dissolution. The Lower Cretaceous Woodbine and Edwards Group carbonate formations contribute dissolved calcium and magnesium, imparting a hard character to the water as it interacts with these soluble rocks — typical of limestone-dominated terrains in the region.

Hard water promotes scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. Dry skin and soap scum are common household effects. Regular appliance deliming and heater flushing are advised; a water softener is recommended to mitigate limescale and extend equipment life. The utility maintains a Superior Water System Rating per Texas standards; the 2020 CCR confirms all contaminants below MCLs; no specific PFAS data noted in available reports; treatment involves coagulation, sedimentation, filtration, and chloramination.

Geology & Source: Elm Fork Trinity River watershed — Lake Lewisville and Lake Ray Roberts surface supplies; Lower Cretaceous Woodbine, Trinity, and Edwards Group limestones and sandstones contribute dissolved calcium and magnesium — hard supply

Other Texas Water Reports

Grapevine

117 mg/L

🟡 Moderately Hard

Colleyville

≈ 120–179 mg/L

🟠 Hard

Trophy Club

≈ 120–179 mg/L

🟠 Hard

Flower Mound

≈ 180+ mg/L

🔴 Very Hard

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Southlake's water safe to drink?

Yes. Southlake's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Southlake?

At ≈ 120–179 mg/L (Hard), Southlake's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does Southlake compare to the USA average?

The USA national average is 151 mg/L. Southlake (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Southlake is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.