Little Elm Water Hardness & Quality Report (2026)

Little Elm, Texas, in Denton County on Lake Lewisville — one of the fastest-growing cities in the entire United States for the 2010s–2020s (Little Elm has consistently ranked among the top 5 fastest-growing large cities in America — the town grew from approximately 3,600 in 2000 to over 55,000 by 2023), a major new community on the shores of Lake Lewisville in the Dallas north exurban corridor, and a diverse Denton County community with a massive influx of young families and professionals in the Dallas–Fort Worth metro — draws its municipal water supply from Lake Lewisville via the Upper Trinity Regional Water District. Water hardness in Little Elm measures 197 mg/L — classified as hard.

Little Elm's hard supply reflects the Denton County Trinity River watershed's calcareous Blackland Prairie and Cross Timbers geology. The Lake Lewisville watershed drains: the Cretaceous Austin Chalk (ultra-calcareous marine chalk of the East Texas Embayment); the Cretaceous Woodbine Formation (moderately calcareous coastal sandstone and shale); the Cretaceous Eagle Ford Shale (calcareous marine shale). The Upper Trinity Regional Water District distributes this calcareous Trinity River supply to Little Elm, producing the hard 197 mg/L.

At 197 mg/L, Little Elm residents face regular hard water challenges. Monthly descaling with citric acid solution is standard maintenance. City of Little Elm Water Division consistently delivers water meeting all Texas TCEQ and EPA Safe Drinking Water Act requirements.