College Station Water Hardness & Quality Report (2026)

College Station, Texas — home to Texas A&M University — draws its municipal water supply through the City of College Station Water Services, sourcing from Lake Carlos and Lake Bryan (City of Bryan impoundments on the Little Brazos and Davidson Creek tributaries) delivered via the Bryan–College Station Water system, and from Brazos River water contracted through the Brazos River Authority. The Navasota River and upper Brazos watershed drains the Brazos Valley region of east-central Texas. Water hardness in College Station reaches 416.5 mg/L — classified as extremely hard.

College Station's extreme hardness reflects the highly calcareous geology of the Brazos Valley watershed in Brazos County. The Brazos River at this reach collects drainage from: the East Cross Timbers sandy terrain (lower hardness contribution); the Cretaceous Navarro–Taylor Marl and Austin Chalk calcareous formations that dominate the Brazos Valley geology; and the calcareous Cretaceous Eagle Ford Shale in the upper watershed. The Brazos Valley's Calcareous Prairie Soils and the underlying Austin Chalk–Navarro Marl sequence produce some of the highest calcium loading of any Texas river system at this latitude. The Bryan–College Station area sits squarely on the Blackland Prairie–Austin Chalk zone, where calcium bicarbonate concentrations rival those of the DFW Metroplex.

At 416.5 mg/L, College Station residents face severe scale challenges — comparable to West Texas Permian Basin cities. Heavy calcium deposits form within days on exposed water surfaces. A whole-house water softener is standard equipment for Texas A&M faculty, staff, and resident households, and the university's facilities management team routinely manages scale in campus building plumbing systems. City of College Station Water Services consistently delivers water meeting all Texas TCEQ and EPA Safe Drinking Water Act requirements.