Moreno Valley Water Hardness & Quality Report (2026)

Moreno Valley, California receives its municipal water through the Eastern Municipal Water District (EMWD), which blends imported State Water Project (SWP) water delivered from the Sacramento–San Joaquin Delta via the Inland Feeder pipeline and Diamond Valley Lake storage facility, with locally pumped groundwater from the Perris Valley Groundwater Basin and the San Jacinto Basin in Riverside County. EMWD's Perris Valley Regional Water Reclamation Facility also contributes recycled water for non-potable irrigation uses. The blended potable supply delivers water at a hardness of 70.5 mg/L — classified as moderately soft.

Moreno Valley's moderate softness reflects the characteristics of its supply blend. State Water Project imports arrive with moderate mineralisation after blending Sacramento and San Joaquin River water. The Perris Valley Groundwater Basin draws from Quaternary alluvial sediments deposited by the San Jacinto River and ancient lake deposits of the Perris basin — relatively young, coarse-grained fluvial material that limits prolonged calcium and bicarbonate dissolution compared with deeper, older carbonate aquifers. The result is a supply noticeably softer than many Inland Empire communities that draw more heavily on groundwater.

With hardness at 70.5 mg/L, Moreno Valley residents experience light scale formation that is easy to manage. Occasional light deposits may appear on showerheads and faucet aerators after several months, and kettles develop a minor mineral ring over time — quarterly descaling with citric acid is generally sufficient. Glassware from dishwashers tends to be largely spot-free, and soap and shampoo lather well. Hot water systems experience minimal scale build-up, making annual servicing a precautionary rather than urgent measure. EMWD's blended system provides a high-quality, reliable supply throughout the Moreno Valley service area.