Calabasas Water Hardness & Quality Report (2026)

Calabasas, California, in Los Angeles County in the Santa Monica Mountains at the western edge of the San Fernando Valley — a celebrity enclave known for its gated communities, the Leonis Adobe Ranch, and proximity to Malibu Creek State Park — receives its municipal water from the Las Virgenes Municipal Water District (LVMWD), which draws entirely from Metropolitan Water District of Southern California (MWD) imported supply — primarily the Colorado River Aqueduct with some State Water Project blending. Las Virgenes serves the western San Fernando Valley communities of Calabasas, Hidden Hills, and the Malibu corridor.

The moderately hard 179 mg/L hardness and elevated TDS of 550.7 mg/L reflect Las Virgenes' heavy dependence on the Colorado River Aqueduct supply. The Colorado River accumulates extensive dissolved mineral loads crossing the Permian Kaibab Limestone (Grand Canyon cap rock), Triassic Moenkopi red beds, Permian Coconino Sandstone, and Jurassic Navajo Sandstone evaporite-bearing formations of the Colorado Plateau, plus concentration from Lake Mead evaporation before the aqueduct delivers water to Los Angeles. The Las Virgenes district has minimal SWP import to dilute the harder Colorado component compared to LADWP service areas with more SWP blending.

At 179 mg/L, Calabasas residents deal with moderately hard water affecting household appliances over time. Scale builds in kettles and coffee machines within weeks, dishwashers benefit from rinse aid treatment, and the elevated TDS produces a perceptible mineral character in tap water. Quarterly descaling of heating appliances is the standard schedule for this San Fernando Valley western community. The PFAS level of 7.1 ppt warrants a certified drinking water filter — Calabasas's position adjacent to former Rocketdyne/Boeing Santa Susana Field Laboratory (one of California's most significant PFAS contamination sites) contributes to elevated PFAS in the Las Virgenes service area.