Cathedral City Water Hardness & Quality Report (2026)

Cathedral City, California, in Riverside County in the Coachella Valley adjacent to Palm Springs — a major Coachella Valley desert community with a large Latino population, a growing arts district, and the Agua Caliente Band of Cahuilla Indians reservation boundary — draws its municipal water supply from the Coachella Valley Groundwater Basin (Mission Creek sub-basin) and Colorado River Aqueduct imports via the Coachella Valley Water District (CVWD). Water hardness in Cathedral City measures 171 mg/L — classified as hard.

Cathedral City's hard supply reflects the Coachella Valley desert aquifer's calcareous geology and imported water blend. The Coachella Valley Groundwater Basin (Quaternary bajada alluvial fans from the San Jacinto Mountains — calcareous desert alluvium with significant dissolved calcium from calcareous caliche soil and the Peninsular Ranges calcareous marble exposures in the San Jacinto Mountains) carries moderately hard groundwater. The Colorado River Aqueduct import (moderately hard Colorado River water, approximately 270–310 mg/L) blended with the local Coachella Valley groundwater produces the hard 171 mg/L at Cathedral City — elevated by the desert environment's concentration effects.

At 171 mg/L, Cathedral City residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and appliances within weeks — monthly descaling with citric acid solution is standard maintenance. Coachella Valley Water District consistently delivers water meeting all California SWRCB and EPA Safe Drinking Water Act requirements.