Kyle Water Hardness & Quality Report (2026)

Kyle, Texas, in Hays County — one of the fastest-growing cities in the United States (Kyle has been consistently among the top fastest-growing large cities in the US — a major Hays County suburban community in the booming Austin south metro, growing from approximately 5,000 residents in 2000 to over 65,000 residents by the mid-2020s), adjacent to San Marcos and Buda in the Austin south suburban corridor along I-35, home of Seton Medical Center Hays (a major south Austin area hospital), and a diverse Hays County community with a significant Latino-American, tech professional, and University of Texas at San Marcos student population — draws its municipal water supply from the Edwards Aquifer via the City of Kyle Water Division. Water hardness in Kyle measures 147.5 mg/L — classified as moderately hard.

Kyle's moderate hardness reflects the Hays County Edwards Aquifer's calcareous Cretaceous limestone geology. The Edwards Aquifer at Kyle–Hays County draws from: the Cretaceous Edwards Limestone (highly calcareous marine limestone — the primary south-central Texas carbonate aquifer); the Cretaceous Georgetown Formation (calcareous limestone); and the Cretaceous Walnut Formation (calcareous marl). City of Kyle treatment produces the moderate 147.5 mg/L — representing effective treatment of the highly calcareous Edwards Aquifer source.

At 147.5 mg/L, Kyle residents encounter moderate scale accumulation. Monthly cleaning with citric acid solution is recommended. City of Kyle Water Division consistently delivers water meeting all Texas TCEQ and EPA Safe Drinking Water Act requirements.