Katy Water Hardness & Quality Report (2026)

The City of Katy Public Works Department manages the drinking water for about 65,000 people in Katy, Texas, and nearby unincorporated areas of Harris and Fort Bend Counties. Their water comes entirely from groundwater, drawn from multiple municipal wells tapping into the Gulf Coast Aquifer System. Specifically, the Chicot and Evangeline Aquifers are the sources, located within the Brazos-Colorado River Basin recharge zone. Treatment is handled at wellhead facilities, involving chlorination for disinfection and basic filtration, before the water is distributed. This system has consistently earned a Texas Commission on Environmental Quality 'Superior Water System' rating for over three decades.

The groundwater originates from Pleistocene and Miocene sands and clays within the Gulf Coast Aquifer System. These geological formations, influenced by Gulf Coast salt domes, are rich in shell fragments and evaporitic minerals. As water moves through these sediments, it dissolves alkaline earth metals like calcium and magnesium, resulting in a very hard water supply with elevated mineral content. Agricultural runoff from Waller and Austin Counties can leach contaminants into the aquifer recharge zones, while natural weathering processes also contribute metals to the water.

This very hard water can lead to significant scale buildup inside pipes, water heaters, dishwashers, and washing machines, which not only reduces their efficiency but also their lifespan—water heaters, for example, may fail up to three times sooner. You might also notice staining on fixtures and laundry, often due to iron present in the supply, and experience dry skin or soap scum that doesn't rinse away easily. To combat these issues, homeowners can benefit from annual descaling of appliances, using vinegar to clean showerheads, and scheduling professional inspections. Installing a water softener is highly recommended for this very hard supply, as it exchanges calcium and magnesium ions, thereby preventing appliance damage and improving the water's usability.