Water Quality

Rancho California Water District Water Quality

Rancho California Water District’s (RCWD’s) water comes from a variety of natural sources. Our natural sources include precipitation, untreated import water recharge basins, and regional groundwater (aquifers). RCWD also purchases treated water from Metropolitan Water District of Southern California. This agency imports water from Northern California and the Colorado River. Water delivered to homes and businesses is a blend of well water (50%) and import water (45%).

Water Demands

Vail DamThe RCWD-managed groundwater basins are estimated to hold over 2 million acre-feet of water. The annual safe yield of these basins is approximately 30,000 acre-feet per year, which meets nearly half of RCWD’s needs. An acre-foot equals about 326,000 gallons, or enough water to cover an acre of land about the size of a football field, one foot deep. An average California household uses between one-half and one acre-foot of water per year for indoor and outdoor use. Surface water from Vail Lake and Lake Skinner is used to help replenish our groundwater supplies through recharge operations.

All aquifers managed by RCWD are located in the Santa Margarita Watershed. Oversight of all groundwater production within the Santa Margarita Watershed falls under the continuing jurisdiction of the United States District Court, San Diego and is administered under the auspices of a court appointed water master (the "Santa Margarita Water Master"). Most of the remaining water demands are met with imported water purchased from Metropolitan Water District of Southern California.

Ensuring Quality

To ensure the highest quality of water is supplied to our customers, RCWD’s water quality staff collects routine samples at several locations throughout the service area. While taking samples, staff monitors chlorine, temperature, pH, and other physical characteristics of the water to verify proper levels. These samples are taken to a laboratory and analyzed for water quality compliance and routine monitoring requirements.

Water Quality Report

Ground water supplies come from production wells located throughout RCWD. These wells require routine sampling independent from the distribution system requirements. Strict sampling techniques are utilized to meet compliance and laboratory requirements. Much of California’s water is stored as snow in the Sierra Nevada Mountains. All results are published annually in the Water Quality Report. 

The annual Water Quality Reports below offer more detailed information about the quality of your drinking water. If you would like the hard copy of the most recent report mailed to you or an electronic copy of an older report, please send us an email

2019 Water Quality Report (PDF)
2018 Water Quality Report (PDF)
2017 Water Quality Report (PDF)
2016 Water Quality Report (PDF)